Durable biofouling protection

Abstract

Disclosed are devices, methods, and / or systems for use in protecting items and / or structures exposed to, immersed in, and / or partially immersed in an aquatic environment from contamination and / or fouling due to invasion and / or colonization by certain types and / or kinds of biological organisms and / or plants, including protection from micro- and / or macro-fouling during extended exposure to the aquatic environment.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 754,574, entitled "DURABLE BIOFOULING PROTECTION," filed November 1, 2018, and U.S. Patent Application No. 62 / 817,873, entitled "BIOFOULING PROTECTIVE ENCLOSURES," filed March 13, 2019, the disclosures of each of which are incorporated herein by reference in their entireties.

[0002] The present invention relates to improved devices, systems, and methods for use in protecting items and / or structures exposed to, immersed in, and / or partially immersed in an aqueous environment from contamination and / or fouling due to infestation and / or colonization by certain types and / or varieties of biological organisms. More specifically, improved methods, apparatus, and / or systems for protecting structures and / or substrates from micro- and / or macro-fouling during extended exposure to an aquatic environment are disclosed. [Background technology]

[0003] The growth and attachment of various marine organisms to structures in aquatic environments, known as biofouling, is a prominent problem for many industries, including the boating and shipping industry, both recreational and industrial, the oil and gas industry, power plants, water treatment plants, water management and control, the irrigation industry, manufacturing, scientific research, the military (including the Corps of Engineers), and the fishing industry. Most surfaces exposed to coastal, harbor, or ocean waters (and their freshwater counterparts), such as boat hulls, underwater cables, chains, and pilings, oil drilling platforms, buoys, and those associated with fishing nets, are eventually colonized by animal species such as barnacles, mussels (as well as oysters and other bivalves), bryozoans, hydroids, tubeworms, ascidians, and / or other urochordata, as well as various plant species. Biofouling results from the interaction between various plant and / or animal species with aspects of the substrate to which they ultimately attach, which leads to the formation of adhesives that firmly bind the biofouling organisms to the substrate, which leads to biofouling. Although seemingly simple, the process of biofouling is a highly complex web of interactions influenced by a myriad of microorganisms, macroorganisms, and the ever-changing characteristics of the aquatic environment.

[0004] The economic impact of biofouling is of utmost concern to many industries. Massive biofouling of ships can result in corrosion of various surfaces exposed to the aquatic environment, a significant reduction in the vessel's operational efficiency, and in many cases, eventual deterioration of parts of the ship. The accumulation of macroorganisms also causes an increase in the roughness of the ship's surfaces, which causes the ship to experience greater frictional resistance, reduced speed and maneuverability, and increased drag, resulting in increased fuel consumption. These increased costs are experienced by commercial and recreational boaters alike, as barnacles and other animals attach to propellers, drive system components, inlets, and / or submerged hull components.

[0005] In addition to increased corrosion and other damage to structures, the weight and distribution of macrofouling on an object can also dramatically change the buoyancy or stresses and strains experienced by the object and / or supporting structure, which can lead to premature failure and / or sinking of the contaminated object. For example, a navigational buoy or pier support that contains a surface with a large amount of biofouling will experience increased stress loads resulting from increased weight and may even collapse or sink under excessive amounts of macrofouling. This increased stress often results in a reduced useful life of the structure, requiring continuous cleaning and / or replacement. Similarly, submersible sensors (including rope-type sensors and / or free-floating sensors) will often fail and / or malfunction relatively quickly (often in less than 30 days) due to invasion and / or colonization by marine organisms.

[0006] Biofouling also creates significant ecological problems due to the distribution of plant and animal species into alien environments when they "hit" on contaminated objects, and substantial legislative and financial resources have been allocated to combating the commercial and ecological impacts of biofouling.

[0007] Various methods have been used in an attempt to stop and / or reduce the accumulation of biofouling. One of the more common methods, especially in the boat and marine industry, is the removal of biofouling by scraping. However, scraping is labor intensive, can damage contaminated surfaces, and environmental concerns have been raised due to concerns that scraping increases the spread of invasive species, resulting in negative environmental impacts on local fauna. Therefore, there is a need for a device that eliminates or reduces the amount of biofouling on surfaces exposed to aquatic environments.

[0008] One strategy for protecting objects in contact with water and preventing aquatic biofouling involves the use of physical coatings. These coatings act as protective devices, desirably by shielding or isolating the structure from the water. For example, U.S. Patent No. 3,220,374 discloses a marine protective device. The invention is directed to unique means and methods for protecting marine equipment from the corrosive effects of water and / or marine growths when the boat is not in use.

[0009] U.S. Patent No. 3,587,508 discloses an outdrive protection device for easy attachment to a boat. The device protects the outdrive of an inboard / outboard motor from marine growths when the boat is not in use. A bag is disposed about the outdrive unit for easy attachment to the transom of the boat in a manner that provides a watertight seal between the bag and the transom and around the outdrive unit.

[0010] No. 4,998,496 discloses a shroud for a marine propulsion system including a watertight shroud body that can be fastened to the transom of a boat to surround an outboard portion of the propulsion system. A locking and sealing mechanism secures the shroud to the boat transom in watertight engagement, and a submersible pump is operable to remove water from the shroud body so that the propulsion system is effectively "dry-docked" when not in use.

[0011] U.S. Patent No. 5,072,683 discloses a drainable protective boat motor bag apparatus including a boot defining a bag for fitting over the propeller and stem of an outdrive of a motor mounted on the stern of a boat. The bag includes a channel extending from a mouth to a closed end of the bag for receipt of an open-ended hose so that once the bag is positioned over the stem, the hose may be inserted for pumping of residue from such bag. A tie string may be incorporated around the mouth of the bag for tying the mouth of the bag to the stem, and if desired, a separate protective sack may be included to cover the propeller blades and protect them from direct exposure to the bag itself.

[0012] U.S. Patent No. 5,315,949 discloses an apparatus for protectively covering a motor prop of a boat. The cover includes an adjustable collar, a flexible opaque bag, and an adjustable collar drawline. The bag has an open top end attached to the collar. A closed bottom end of the bag is opposite the top end and has a weight attached thereto. The adjustable collar drawline of the collar is such that with the bag positioned over the outcrop, the open end of the bag may be closed around the outcrop by pulling the adjustable collar drawline. The collar includes a locking slot for locking the adjustable collar drawline in place around the outcrop. An operating handle is removably attached to the collar for facilitating placement and removal of the cover from the outcrop. With the cover in place over the outcrop, water and light are preferably prevented from entering the interior of the bag, thereby preventing aquatic organisms, such as filter-feeding organisms and plants, from preferably reproducing within the cover.

[0013] No. 6,152,064 discloses a protective propeller cover. The cover includes a flexible sleeve in which a buoyant material is disposed to provide a buoyant enclosure. A flexible propeller cover portion is secured to the flexible sleeve and an end of the cover is releasably secured around the propeller. The buoyant enclosure is positioned adjacent to the propeller and extends above the water line when the propeller is positioned below the water line. The buoyant enclosure also functions to protect swimmers from direct contact with the propeller when swimming near the boat. The protective propeller cover apparatus further functions to protect the propeller during transportation or storage. The protective propeller cover apparatus further functions as an anchor cover when the boat is underway. The protective propeller cover apparatus further functions as an emergency flotation device.

[0014] U.S. Patent No. 6,609,938 discloses a propeller protector slipper for use on inboard and outboard motors of boats that are anchored, adrift, stranded, docked, stored, or out of the water while in transit. The propeller protector slipper protects the propeller from elements that would cause pitching and damage to the propeller, minimizing propeller-related damage. The propeller protector slipper also provides a gauge to project the distance of the towed boat's propeller from the following vehicle.

[0015] US Patent Application Publication No. 2008 / 0020657 discloses an apparatus for protecting an outdrive of a marine vessel. The apparatus comprises a positioning member adapted to mount to the underside of a marlin board of the marine vessel, and a shroud engageable with the positioning member to provide an enclosure around the outdrive. The shroud is buoyant and may be floated into sliding engagement with the positioning member. The shroud desirably has an opening that is closed upon engagement of the shroud with the transom of the marine vessel to prevent ingress of water to the inside of the shroud. Connecting and locking means are provided for releasably connecting the shroud to the positioning member.

[0016] In addition to the use of physical coatings as exemplified above, other strategies have been employed in efforts to reduce biofouling. US Patent Application Publication No. 2009 / 0185867 discloses a system and method for reducing vortex-induced vibration and drag around a marine element. The system includes, but is not limited to, a shell rotatably mounted around the marine element, the shell having opposing edges defining a longitudinal gap configured to allow the shell to snap around at least a portion of the marine element. Fins may be positioned along each opposing edge of the longitudinal gap, each fin extending outwardly from the shell. The fins may be desirably positioned on the shell to reduce vortex-induced vibration and minimize drag on the marine element. One or more anti-fouling agents may be disposed on, in, or around at least a portion of the shell, the fins, or a combination thereof.

[0017] US Patent No. 7,390,560 discloses a coating system for defouling a substrate. The system includes a ship hull submerged in water or seawater for an extended period of time. The system includes a conductive layer, an anti-fouling layer, and a means for providing an energy pulse to the conductive layer. The conductive layer includes a polymer, such as carbon-filled polyethylene, that is conductive. The anti-fouling layer includes a polymer, such as polydimethylsiloxane, that has a low surface free energy. The layers are designed such that the conductive layer separates from the anti-fouling layer when the conductive layer is exposed to a pulse of electrical, acoustic, or microwave energy, or a combination thereof.

[0018] US Patent No. 6,303,078 discloses an anti-fouling structure for protecting objects in contact with seawater, which may include a water-permeable fibrous material incorporating a molded thermoplastic or woven fabric containing a large amount of an anti-fouling agent, which leaches from the structure into the seawater. According to this reference, it is important that the leaching agent maintain a high concentration of the anti-fouling agent near the object to prevent attachment of aquatic organisms. In addition, many of the embodiments of the enclosure disclosed by this reference create an environment with very low dissolved oxygen levels (i.e., 8.3% or less), which is highly anoxic and tends to promote excessive microbial corrosion and decomposition of the protected object.

[0019] A wide variety of surface coatings, paints, and / or other materials are also known in the art for application to the exterior surfaces of underwater objects in an attempt to directly shield and / or isolate these objects from the effects of biofouling. Many of these coatings and / or other materials rely on biocidal and / or metallic additives (i.e., copper) that desirably leach into the surrounding aqueous environment over time to impede various aspects of biofouling organisms. For example, divalent Cu 2While tributyltin (TBT) biocides (now banned for use as marine biocides in many developed countries) and / or other organotin compounds kill or retard the growth of many marine organisms, many of these substances may also function as endocrine disruptors. However, the process of preparing the underwater surface(s) of an object and then applying and / or bonding such paints / coatings directly to such surface(s) is often a costly and time-consuming process (which may even require removal of the object from the aqueous environment and / or dry-docking of the vessel), and all of these coatings have a limited duration, typically lose effectiveness over time, and often have harmful (and undesirable) effects on organisms in the surrounding aqueous environment. Similar difficulties exist for systems that rely on dissolution and / or surface properties, such as hydrophobic, superhydrophobic, and / or non-adhesive (i.e., non-sticky and / or super-ciliated) surfaces.

[0020] More recently, systems that rely on the release or creation of active caustic agents such as chlorine that are released into the aqueous environment (i.e., electrochlorination systems that generate hypochlorite compounds from seawater) have been used in attempting to reduce and / or prevent biofouling, particularly in cooling and / or filtration water systems for large industrial facilities. In addition to the high cost of purchasing and / or operating such systems, such corrosive substances (which in the case of chlorine can be a strong oxidizer) can cause harmful effects far beyond the intended environment of use (i.e., once released, they can damage organisms in the surrounding aquatic environment), and many of these substances can promote corrosion and / or degradation of the very items they are intended to protect or associated system components.

[0021] Various attempts have also been made in the art to completely isolate objects from biofouling elements in an aqueous environment, such as by creating a completely sealed environment around the object intended to be protected from biofouling. However, in these cases, the liquid contained within the sealed environment (which is also in direct contact with the object to be protected) typically becomes stagnant and / or anoxic very quickly, leading to high levels of anaerobic corrosion of various materials, especially in anoxic sulfate-rich environments such as anoxic seawater. Summary of the Invention

[0022] The various inventions disclosed herein involve an understanding of the need for improved methods, apparatus, and / or systems for protecting structures and / or substrates from micro- and / or macro-fouling for extended periods of exposure to an aquatic environment, including situations where it may be impractical, impossible, and / or inconvenient for a completely sealed "enclosure" or other type of outer covering to be continuously utilized around an exposed substrate structure. This includes situations where a substrate or other object is moving through the aqueous environment or providing some form of propulsion (i.e., a ship's propeller and / or a boat's hull), where the surrounding water in the aqueous environment is being circulated, consumed, and / or utilized (i.e., for cooling water and / or distilled for fresh water), and / or where sensors or other devices are utilized to record and / or sample the surrounding aqueous environment.

[0023] The various inventions disclosed herein further include the understanding that a completely sealed enclosure that completely isolates the substrate from the surrounding aqueous environment may not adequately protect the substrate from various adverse effects of the aqueous environment, in that the "protected" substrate may be subject to corrosion or other effects from anoxic, acidic, and / or other conditions that may be present within and / or in close proximity to the substrate (and / or other conditions associated with such surrounding environments, such as the action of microbial induced corrosion). Thus, optimal protection of the substrate may be provided by an enclosure that at least partially (but not completely) isolates the substrate from various features and / or aspects of the surrounding aqueous environment.

[0024] In various embodiments, biofouling prevention "enclosures" or "barriers" are described that may be positioned around, against, and / or otherwise near a substrate or other object to filter, screen, separate, isolate, protect and / or shield the substrate from one or more features or characteristics of the surrounding aqueous environment, including the adoption of various embodiments described in co-pending U.S. patent application Ser. No. 62 / 754,574, entitled "DURABLE BIOFOULING PROTECTION," filed Nov. 1, 2018, and co-pending U.S. patent application Ser. No. 62 / 817,873, entitled "BIOFOULING PROTECTIVE ENCLOSURES," filed Mar. 13, 2019, the disclosures of which are incorporated by reference in their entireties. More specifically, various embodiments of the enclosure desirably form a "bounded," enclosed, and / or distinct aqueous environment in the immediate vicinity of the substrate, which may function to filter or insulate the substrate from direct biofouling by certain types of micro- and / or media, as well as, in at least some cases, to promote the formation of a relatively durable surface, coating, or layer on the substrate and / or enclosure walls, which may potentially inhibit, hinder, avoid, and / or prevent subsequent establishment, recruitment, and / or colonization of the substrate surface by undesirable types of biofouling organisms for extended periods of time, even in the absence of the enclosure. In many cases, the fenestrations in the enclosure walls allow for a certain amount of water exchange between the aqueous environment within the enclosure and the aqueous environment outside the enclosure, and in some cases may change the chemical composition and / or turbidity of the liquid water contained within the enclosure, leading to different levels of clay, silt, finely divided inorganic and organic matter, algae, soluble colored organic compounds, chemicals and compounds, plankton and / or other microscopic organisms suspended in the differentiated liquid compared to that of the surrounding open aqueous environment, which levels may contribute in various ways to fouling and / or corrosion (or lack of fouling and / or corrosion) of substrates contained within the enclosure.

[0025] In various embodiments, the enclosures described herein act to create an "enclosed," "localized," "contained," and / or "differentiated" aquatic environment adjacent to the submerged and / or partially submerged portions of the substrate or surface to be protected that is or becomes unfavorable to the settlement and / or recruitment of various types of biofouling-contributing aquatic organisms (which may include surfaces that create "negative" settlement cues, as well as surfaces that may lack and / or exhibit reduced levels of "positive" settlement cues for one or more types of biofouling organisms). The enclosure(s) of various embodiments may also desirably filter, reduce, and / or prevent many biofouling-contributing marine organisms from entering the enclosure and / or contacting the submerged and / or partially submerged surfaces of the substrate.

[0026] In various embodiments, the enclosure may include a permeable formable substrate, a fibrous substrate, and / or a fabric material, which in at least one exemplary embodiment may include a woven polyester fabric made from spun polyester yarns. In at least one further embodiment, the employment of spun polyester yarns may desirably increase the effective surface area and / or fibrillation of the fabric material on a microscopic and / or microscopic scale, which may desirably (1) lead to a significant decrease in the "effective" or average size of natural and / or artificial openings extending through the fabric, (2) decrease the amount and / or width of "free space" within openings through and / or within the fabric, thereby potentially decreasing the separation distance between the surface of the fabric and microorganisms (within the inflow / outflow liquids), and / or (3) alter and / or induce changes in water chemistry within the enclosure in various ways. The reduced average opening size of the fabric will desirably increase the "filtration" of liquids to reduce and / or prevent various biological organisms and / or other materials from entering the enclosed or bounded environment, while the reduced "free space" within the opening(s) will desirably reduce the opportunity for organisms to pass freely through the fabric and / or reduce the rate and / or amount of "total water exchange" between the enclosed or bounded environment and the open aqueous environment. These factors will desirably result in a significant reduction or metering in the size and / or viability of micro- and macro-organisms (as well as various organic and / or inorganic contaminants and / or other compounds) that enter and leave the enclosure. Furthermore, these aspects will also desirably reduce the amount, extent and / or rate of biofouling or other degradation that may occur within the enclosure material itself and / or its opening(s), and desirably maintain the flexibility, permeability and / or other properties of the enclosure fabric over time.

[0027] Desirably, at least a portion of the fabric wall of the enclosure will be fenestrated and / or perforated to a sufficient extent to allow some amount of liquid and / or other substance(s) to pass and / or "filter" through the wall of the enclosure in a relatively controlled and / or metered manner (i.e., from the exterior or "open" aqueous environment to the differentiated aqueous environment and / or from the differentiated aqueous environment to the exterior or open aqueous environment), desirably providing a certain level, amount, and / or percentage of "bulk liquid flow" and / or "total liquid exchange" to occur between the differentiated environment (within the enclosure) and the surrounding open aqueous environment (outside the enclosure), as well as the potential for diffusing or otherwise passing through the enclosure wall and / or their pores. These movements of liquids and / or other compositions, in combination with various natural and / or man-made processes, desirably induce, promote and / or create a relatively "different" or dynamic "man-made" environment within the enclosure, particularly an environment having properties that differ in many ways from the dynamic properties of the surrounding aqueous environment, desirably providing a differentiated environment that is "undesirable" for many biofouling organisms, thereby reducing and / or eliminating biofouling from occurring within and / or immediately outside of the enclosure. In addition, the presence of numerous small perforations in the walls of the enclosure desirably provides various levels of filtration of the exchange liquid(s), potentially reducing the number and / or survival rate of organisms entering the enclosure, as well as adversely affecting organisms outside the enclosure that may pass within and / or near the enclosure walls.

[0028] As an example, the amount of dissolved oxygen in the liquid within the enclosure will desirably differ to a significant extent from the amount of dissolved oxygen in the liquid of the external aqueous environment, with changes in dissolved oxygen in the differentiated liquid potentially reflecting, tracking, and / or "lagging" (changing in amount) the dissolved oxygen level in the external aqueous environment. Desirably, this dissolved oxygen level in the differentiated liquid will typically be below that of the surrounding aqueous environment (although in various embodiments it may be equal to or greater than that of the surrounding environment, including periodically and / or continuously), and in various embodiments the dissolved oxygen level may fluctuate above a level that encourages sulfate reduction or similar bacterial activity (i.e., microbially induced corrosion - "MIC") and / or other anaerobic decomposition / corrosion, the fluctuations themselves desirably helping to inhibit and / or control the dominance of any single undesirable type or group of micro- and / or macro-organisms within the enclosure or various sections or portions thereof.

[0029] In various embodiments, a gradient of dissolved oxygen and / or other water chemistry may develop within the enclosure liquid between the interior wall of the enclosure and the exterior surface of the protected substrate, potentially creating a "more comfortable zone" adjacent the interior wall of the enclosure and / or a "less comfortable zone" adjacent the surface(s) of the substrate, which in some embodiments may induce various microorganisms to migrate toward the inner enclosure wall and / or away from one or more surfaces of the substrate (which may be due, as one example, to increased dissolved oxygen percentages that may be present closer to the enclosure wall), and potentially propelling some microorganisms not to colonize, establish, reproduce, and / or grow on the surface(s) of the substrate. In various embodiments, this gradient may be due, at least in part, to the inflow of water through and / or into the enclosure, and / or may be due, at least in part, to the outflow of water through and / or out of the enclosure. The resulting "exchange" of water into and / or out of the enclosure, and the various concentrations of chemicals and / or compounds contained therein, will desirably reduce the amount, extent, and / or rate of biofouling or other degradation that may occur to the substrate in its native (i.e., unprotected) state.

[0030] In various embodiments, water or other aqueous medium entering and / or exiting the enclosure will desirably accomplish this passage primarily in a "bulk" manner, minimizing localized variations in the velocity and / or "flow" of the water within the enclosure. The resulting relatively stationary nature of the water within the enclosure desirably reduces and / or inhibits significant "mixing" of the water within the enclosure, desirably leading to higher levels of stratification and / or differentiation within the enclosure, which may include stratification based on oxygenation levels (i.e., chemocline) and / or other properties (i.e., salinity, density, temperature), potentially leading to the formation of localized regions of anoxia and / or euxonia within the enclosure (regions that may be suspended within the enclosure and / or separated from the surface of the substrate by other regions of water within the enclosure). Additionally, water exiting the enclosure, which may contain various metabolic waste products and / or harmful compounds (including various known and / or unknown microbial "toxins") and / or other inhibitory compounds produced within the differentiated environment, will desirably "linger" within the pores of the enclosure and / or near the exterior walls of the enclosure in a "horde" of such water / compounds for various lengths of time, desirably reducing and / or preventing colonization of the enclosure walls (including exterior-facing walls) by fouling organisms.

[0031] In one exemplary embodiment, an enclosure may be utilized in proximity to a substrate to create an oxygen-depleted zone within the enclosure, with at least a portion of the oxygen-depleted zone being in proximity to or in contact with the substrate, and in some embodiments, the oxygen-depleted zone may include the entirety of the differentiated aqueous environment (i.e., within the enclosure), while in other embodiments, the oxygen-depleted zone may include only a portion of the differentiated aqueous environment. Desirably, various aspects of the unique design and configuration of the enclosure will allow one or more natural processes to initially generate the oxygen-depleted zone, although in some embodiments, additional measures and / or activities may be taken to initiate, accelerate, maintain, retard, reduce, and / or supplement one or more natural process(es) thereby affecting the resulting oxygen-depleted region.

[0032] Desirably, the enclosure will provide a unique protected environment within the aqueous environment, and the amount and / or diversity of bacteria and / or other microorganisms within the enclosure may differ from those located outside the enclosure. Additionally, the enclosure may form multiple distinct environments within the enclosure, including a first distinct "environment" that may be quantified as "proximate to the interior wall of the enclosure" (i.e., within a few millimeters of the interior wall of the enclosure) and a second distinct "environment" that may be quantified as proximate to the exterior surface of the substrate (i.e., within a few millimeters). In various exemplary embodiments, a given distinct environment may induce or promote the formation of one or more biofilms within the enclosure, which may include the formation of a biofilm on the surface of the substrate, which may differ in various ways from a biofilm that may form on a substrate in the aqueous environment without the enclosure and / or a different biofilm on the interior surface of the enclosure wall or within the pores of the enclosure wall. For example, a substrate biofilm within an "enclosed" or differentiated environment may incorporate a lower / less diversity of bacteria or other microorganisms or may include a "thinner" layer of biofilm than would normally form on the surface of an equivalent unprotected substrate. In various instances, this differentiated biofilm may be advantageous for preventing and / or reducing micro- and / or macro-fouling of the substrate.

[0033] In some embodiments, the unique protected environment within the aqueous environment may induce a unique amount and / or diversity of bacteria and / or other microorganisms within the enclosure, which may induce or enhance the formation of one or more biofilm(s) within the enclosure, and such biofilms may be less "tightly attached" to the substrate than biofilms typically encountered in unprotected environments. Such biofilms may facilitate removal and / or "scraping" of fouling organisms from the substrate and / or intermediate biofilm layers. In such cases, the microflora and / or microfauna may include different phyla (i.e., different bacteria, cyanobacteria, and / or diatoms) than those located outside the enclosure.

[0034] In various embodiments, the presence of the enclosure and the various perforations(es) therethrough may form a "differentiated" aqueous environment that may be less conducive to micro- and / or macro-fouling of the substrate than the surrounding aqueous environment, and may include the existence and / or presence of cues for localized biofilm colonization within the differentiated environment that are at a lower positive level than cues for localized biofilm colonization in the surrounding aqueous environment. Desirably, the enclosure will create "differences" in the composition and distribution of various environmental factors and / or compounds within the differentiated aqueous environment compared to similar factors and / or compounds in the surrounding open aqueous environment, and these "differences" inhibit and / or prevent a significant amount of biofouling from occurring (1) on the surface of the protected substrate, (2) on the interior wall surfaces of the enclosure, (3) within the interstices of the openings and / or perforations in the walls of the enclosure, and / or (4) on the exterior wall surfaces of the enclosure. In some embodiments, the enclosure will create a gradient of colonization cues within the enclosure that induces and / or promotes some and / or all of the micro- and / or macrofouling organisms to be located some distance from the substrate, while in other embodiments the enclosure may create a microenvironment proximate to the substrate that is not conducive to biofouling and / or other degradation of the substrate. In still other embodiments, the enclosure may be positioned proximate to and / or in direct contact with the substrate, such as wrapped directly around the substrate, and still provide the various protections described herein.

[0035] In various other embodiments, the presence of a perforated enclosure wall may similarly affect various water chemical composition factors and / or the presence / absence of nutrients and / or waste products within the separated environment and / or portions thereof, as compared to those of the surrounding aqueous environment. For example, pH, total dissolved nitrogen, ammonium, nitrate, nitrite, orthophosphate, total dissolved phosphate, and / or silica may vary between the separated environment and the surrounding open aqueous environment, and even within the separated environment, such nutrient levels may vary across the enclosed or bounded aqueous region. In general, the water chemical composition, nutrient levels, and / or waste metabolite levels in the liquid within the enclosure at a location proximate at least a portion of the enclosure wall (i.e., the "upstream portion" based on the direction of the bulk water flow) may more closely resemble the levels of the liquid outside the enclosure, with greater variations typically being found within the enclosure and / or proximate the substrate surface.

[0036] In various embodiments, the presence of an enclosure as described herein may alter the chemical composition of the water such that fouling organisms that may land on the substrate may not settle or attach to the substrate and / or may not be able to reproduce and / or colonize the substrate due to various "unfriendly" conditions within the differentiated environment that render the organisms unable to grow (including unable to grow as fast as comparable organisms located outside the enclosure), unable to reproduce, and / or unable to go through one or more of the required natural processes and / or stages that these organisms undergo to become fully functional macrofouling organisms. For example, various chemical composition changes may occur within the enclosure (compared to the surrounding open aqueous environment), including reduced dissolved oxygen levels, changes in pH, differences in nutrient levels and / or concentrations, waste levels, and / or lack of water movement within the enclosure, etc. In many cases, fouling organisms may also be cleaved and / or "killed" from an already contaminated surface when the substrate is placed within the various enclosures described herein, potentially stopping and / or reducing fouling of the substrate as well as potentially loosening and / or detaching some existing biofouling organisms and / or skeletal remains such as shells, skeletons, exoskeletons and / or associated support structures from the contaminated surface(s).

[0037] In various embodiments, the arrangement, small size and / or distribution of the perforations in the enclosure wall, as well as the presence of various sutures and / or suture portions (i.e., cilia) located therein, may limit, prevent and / or regulate the presence and / or availability of sunlight or other light / heat energy (including artificial and / or bioluminescent energy sources) within the enclosure or various portions thereof, including limiting and / or preventing various energy sources (e.g., sunlight for photosynthesis, etc.) from being readily available for use by various microorganisms and / or other degenerative processes, particularly when the enclosure is utilized near the surface of an aqueous environment or near such other energy sources. If desired, the availability or presence of such energy sources in proximity to the enclosure wall (i.e., through the perforations) may induce some motile organisms to crowd and / or congregate in proximity to the interior walls of the enclosure, desirably reducing their presence in proximity to the substrate surface to be protected. In various alternative embodiments, light or other energy sources may be located in the surrounding aqueous environment proximate to the enclosure and / or may remain within the enclosure at various locations, including proximate to the protected substrate, thereby improving the availability of such energy sources proximate to and / or within the enclosure. Such embodiments may be particularly useful in limiting the presence and / or growth of biofouling organisms that are sensitive to the added energy source (i.e., providing a light source to inhibit zebra mussels, which typically prefer darker environments).

[0038] In various embodiments, the placement, small size and / or distribution of the perforations in the enclosure wall, as well as the presence of various threads and / or thread portions therein, may limit, prevent and / or regulate the location and / or amount of higher velocity bulk flow(s) that may occur within the enclosure or various portions thereof, including limiting and / or preventing various types of laminar and / or turbulent flow(s) of liquid within the enclosure and / or adjacent to the substrate (i.e., localized streams or "jets" of water). In some embodiments, the relatively "slow" but not completely "static" nature of the water that may be achieved within the enclosure may prevent significant numbers of non-sessile microorganisms from coming into contact with the substrate or the boundary layer adjacent thereto. Additionally, the restricted flow of liquid within the enclosure may allow a thinner / thicker aqueous liquid boundary layer to exist in close proximity to the protected substrate and / or enclosure walls, which may further limit microbial or other contact with the protected substrate as well as induce or allow the formation of a thinner / thicker biofilm layer on the substrate than would normally be present in the more vigorous flow conditions(s) of an open aqueous environment.

[0039] In at least one alternative embodiment, various advantages of the present invention may be provided by an impermeable enclosure (including plastic, wood and / or metal wall sheets or plates, etc.) incorporating supplemental and / or artificial water exchange mechanisms, such as powered pumps or "check valve" arrangements, propeller systems and / or petal systems, that provide a desired level of water exchange between the differentiated aqueous environment and the surrounding open aqueous environment.

[0040] In some embodiments of the invention, some or all of the biofouling protection and / or effectiveness described herein for the protected substrate may desirably be provided by the enclosure and its permeable formable matrix, fibrous matrix, and / or fabric wall materials without the use of various supplemental biofouling prevention agents, while in other embodiments the enclosure may include a permeable formable fibrous matrix and / or fabric wall material that incorporates one or more biocides and / or anti-fouling agents in some portion(s) of the wall structure and / or its coating. In some embodiments, the biocide and / or anti-fouling agent(s) may provide biofouling protection to the enclosure walls and / or components (the enclosure itself provides some level of biofouling protection to the substrate), while in other embodiments the biocide and / or anti-fouling agent(s) may provide some level of biofouling protection to the substrate itself, and in still other embodiments the biocide and / or anti-fouling agent(s) may provide biofouling protection to both the enclosure and the substrate, and / or various combinations thereof.

[0041] In some embodiments, the enclosure may provide biofouling protection to different degrees for both the substrate and the enclosure walls, even in the absence of supplemental biocides or other fouling protection substances, inhibitors and / or toxins that may be integrated into the enclosure structure and / or may be provided supplementally. For example, when an enclosure as described herein is placed around a substrate to form the disclosed differentiated environment(s), the environment(s) may also develop elevated concentrations of various metabolic waste products, and various processes and / or metabolic activities occurring within the enclosure may generate one or more substances (e.g., hydrogen sulfide or NH3-N-ammonia nitrogen, etc.) that are harmful, harmful, toxic, and / or have other adverse effects on fouling organisms. For example, NH3-N is the undissociated form of ammonia, also known as free ammonia nitrogen (FAN) or ammonia nitrogen, and has been found to be harmful and / or toxic to microorganisms because it can permeate cell membranes. In some embodiments, desired concentrations of such harmful compounds (including various known and / or unknown microbial "toxins") and / or inhibitory compounds may be developed within the enclosure (and these concentrations may then be continually "replenished" by various processes occurring within the enclosure), which may reside in distinct aqueous regions within the enclosure and / or elute through the enclosure walls, potentially creating a localized "swarm" of harmful chemicals that protects to some extent the exterior walls of the enclosure from fouling organisms. However, once these compounds leave the enclosure, these harmful and / or inhibitory compounds may become quickly diluted and / or degraded by various natural processes, thus eliminating significant concerns regarding the longer term effects of these substances on the environment at some distance from the enclosure. In addition, because the processes that create these compounds within the enclosure are continuous and / or cyclical, the enclosure may continually generate and / or elute these inhibitory compounds at relatively constant levels indefinitely, without the need for elution reservoirs and / or external replenishment or power sources.

[0042] In at least one exemplary embodiment, the enclosure may include a permeable formable fibrous matrix of polyester fabric made from spun polyester yarns, which may be coated on at least one side (such as the surface facing the exterior of the enclosure) with a biocidal compound or coating or paint containing a biocide, such that at least a portion of the biocidal compound permeates at least a portion of its way into the body of the fabric. In at least one further embodiment, the employment of ring-spun polyester yarns may desirably increase the effective surface area and / or fibrillation of the fabric material on a microscopic and / or microscopic scale, which may desirably (1) lead to a significant reduction in the average size of the natural openings extending through the fabric, and / or (2) reduce the amount and / or width of "free space" within the openings through and / or within the fabric, thereby potentially reducing the separation distance between microorganisms (in the inflow / outflow liquids) and the biocide coating(s) resident on the fabric. The reduced average opening size of the fabric of such embodiments will desirably increase the "filtration" of liquids to reduce and / or prevent various biological organisms and / or other materials from entering the enclosed or bounded environment, while the reduced "free space" in the opening(s) will desirably improve or amplify the effect of the biocide on organisms passing through the enclosure as the organisms pass in closer proximity to the biocidal coating (including an increased potential for direct contact between the biocide and various organisms). These factors will desirably result in a significant reduction in the size and / or viability of micro- and macro-organisms (as well as various organic and / or inorganic contaminants) passing through the enclosure. Additionally, the presence of the biocide coating(s) and / or paint(s) and / or additive(s) on and / or within the fabric of the enclosure will desirably significantly reduce the amount, extent and / or rate of biofouling or other degradation that may occur in the enclosure material itself and / or within its openings, and desirably maintain the flexibility, permeability and / or other properties of the enclosure fabric over an extended period of time.

[0043] In some embodiments and / or in some aqueous environments, the presence of a biocide coating on at least the exterior surface of the flexible enclosure material will desirably reduce the thickness, density, weight and / or extent of biofouling and / or other degradation experienced on and / or within the openings in the enclosure itself, which will optimally maintain a desired level of water exchange between the enclosure and the surrounding environment and / or extend the useful life of the enclosure in its desired location around the substrate. In many circumstances, biofouling of the enclosure can significantly increase the weight and / or stiffness of the enclosure, damaging the enclosure and / or structures attached to the enclosure (including the substrate itself), as well as adversely affecting the buoyancy of the enclosure and / or any objects attached thereto. In addition, biofouling of the enclosure itself can reduce the flexibility and / or ductility of various fabric components, which can cause and / or contribute to premature tearing and / or failure of the fabric and / or associated attachment mechanisms in dynamic aqueous environments. Additionally, biofouling formation on / within the enclosure can potentially "block" or reduce the size of and / or close the openings through and / or in the enclosure fabric, potentially changing the permeability and / or liquid exchange rates between the differentiated environment and the surrounding dynamic and / or open aqueous environment, potentially resulting in undesirable conditions (i.e., low dissolved oxygen levels and / or anoxia) and / or corrosion or other problems occurring within the enclosure.

[0044] In at least one embodiment, the enclosure may include an initial biocide treatment that is eluted and / or otherwise dispensed for a limited period of time after deployment of the enclosure, which period allows other features of the enclosure to develop a differentiated environment that may generate various inhibitory substances to provide subsequent biofouling protection to the substrate and / or enclosure after elution of the initial biocide has declined to lower and / or less effective levels and / or after elution or dispensing has ceased. [Brief description of the drawings]

[0045] The above and other objects, aspects, features, and advantages of the embodiments will become more apparent and may be better understood by referring to the following description in conjunction with the accompanying drawings.

[0046] [Figure 1] 1 illustrates one exemplary embodiment of an enclosure in the form of a bag or sack. [Diagram 2] 1 illustrates an alternative embodiment of a cylindrical enclosure. [Diagram 3] 1 illustrates another exemplary embodiment of an enclosure having one or more gapped or spaced apart sections. [Figure 4A] 1 illustrates a scanning electron microscope photomicrograph of an exemplary yarn for use within an enclosure. [Figure 4B] 4B illustrates a cross-sectional view of the yarn midbody of FIG. [Figure 4C] 1 illustrates an enlarged view of a knitted fabric containing PET yarn. [Diagram 5] 1 illustrates exemplary rolled sheet fabrics for use in various enclosure designs. [Figure 6A] 1 illustrates exemplary fabric stitching suitable for use in various enclosure designs. [Figure 6B] 1 illustrates exemplary fabric stitching suitable for use in various enclosure designs. [Figure 7A] 1 illustrates one exemplary embodiment of a rolled sheet fabric incorporating an adhesive, hook and loop fastener material. [Figure 7B] 7B illustrates a progressively wrapped enclosure incorporating the fabric of FIG. 7A. [Figure 8A] 1 graphically illustrates exemplary dissolved oxygen levels within various test enclosures compared to the dissolved oxygen levels of the surrounding aqueous environment. [Figure 8B] 1 graphically illustrates exemplary dissolved oxygen levels within various test enclosures compared to the dissolved oxygen levels of the surrounding aqueous environment. [Figure 9]Illustrated are several water chemistry factors inside the enclosure that remained the same or similar to those of the surrounding aqueous environment. [Figure 10A] 1 graphically illustrates dissolved oxygen (DO) levels within various exemplary enclosures compared to DO readings of the surrounding aqueous environment. [Figure 10B] 1 graphically illustrates dissolved oxygen (DO) levels within various exemplary enclosures compared to DO readings of the surrounding aqueous environment. [Figure 10C] 1 graphically illustrates dissolved oxygen (DO) levels within various exemplary enclosures compared to DO readings of the surrounding aqueous environment. [Figure 10D] 1 graphically illustrates dissolved oxygen (DO) levels within various exemplary enclosures compared to DO readings of the surrounding aqueous environment. [Figure 11] 1 illustrates an exemplary cross-sectional view of a substrate and associated enclosure wall within an aqueous environment. [Figure 12A] Illustrates the biological nitrogen cycle as it occurs naturally in various water bodies. [Figure 12B] 1 graphically illustrates an exemplary dependence of NH3-N on available dissolved oxygen levels in an aqueous environment. [Figure 13] Illustrates the pH water chemistry inside the various enclosures, which remained somewhat similar to that of the surrounding aqueous environment. [Figure 14] 1 illustrates an exemplary "standard" progression or colonization sequence of a fouling community on a substrate submerged in an aqueous medium such as seawater. [Figure 15] FIG. 1 illustrates the different distributions of bacterial phyla in biofilms formed on different substrates in seawater. [Figure 16A] 1 illustrates another exemplary embodiment of an uncoated woven polyester fabric. [Figure 16B] 16A illustrates an embodiment of 16A coated with a biocide coating. [Figure 17A] 1 illustrates natural uncoated burlap. [Figure 17B] 17B illustrates the fabric of FIG. 17A coated with a solvent-based biocidal coating and a water-based biocidal coating. [Figure 17C] 17B illustrates the fabric of FIG. 17A coated with a solvent-based biocidal coating and a water-based biocidal coating. [Figure 18A] An uncoated polyester fabric is shown. [Figure 18B] 18B illustrates the fabric of FIG. 18A coated with a biocidal coating. [Figure 18C] Illustrates an uncoated spun polyester fabric. [Figure 18D] 18D illustrates the fabric of FIG. 18C coated with a biocidal coating. [Figure 18E] Illustrates an uncoated spun polyester fabric. [Figure 18F] FIG. 18C illustrates the uncoated side of the spun polyester fabric of FIG. 18E after coating. [Figure 19] Illustrated are various fabrics suitable for use in various embodiments of the present invention. [Figure 20] 1 illustrates detection of rhodamine concentration over time within an exemplary enclosure. [Figure 21] 1 illustrates various plankton types and conditions identified in various enclosure embodiments. [Figure 22A] 22A illustrates a pair of bronze propellers submerged in seawater, with the propellers unprotected in FIG. 22A and protected by an embodiment of an enclosure in FIG. 22B. [Figure 22B] 22A illustrates a pair of bronze propellers submerged in seawater, with the propellers unprotected in FIG. 22A and protected by an embodiment of an enclosure in FIG. 22B. [Figure 23A] 1 illustrates the substrate protected by the enclosure after immersion in seawater for 12 months. [Figure 23B] 23B illustrates an enclosure that protects the substrate of FIG. 23A. [Figure 23C]23B and 23C illustrate an unprotected substrate submerged in seawater for 12 months in proximity to the substrate and enclosure of FIGS. 23A and 23B. [Figure 23D] 1 illustrates a protected substrate. [Figure 23E] 23D illustrates an enclosure that protects the substrate of FIG. 23D. [Figure 23F] 1 illustrates a protected substrate. [Figure 23G] 23F illustrates a natural fiber enclosure that protects the substrate of FIG. 23F. [Figure 24A] Illustrated are the inner surfaces of exemplary enclosures constructed from spun polyester and textured polyester, respectively. [Figure 24B] Illustrated are the inner surfaces of exemplary enclosures constructed from spun polyester and textured polyester, respectively. [Diagram 25] 1 graphically illustrates DO levels within various exemplary enclosures compared to DO readings of the surrounding aqueous environment. [Figure 26A] An unprotected substrate is shown after three months of submersion in fresh water, along with a substrate protected by an embodiment of the enclosure. [Figure 26B] An unprotected substrate is shown after three months of submersion in fresh water, along with a substrate protected by an embodiment of the enclosure. [Figure 27A] Various flexible fabrics suitable for use in constructing various enclosure embodiments are illustrated. [Figure 27B] Various flexible fabrics suitable for use in constructing various enclosure embodiments are illustrated. [Figure 28A] 1 illustrates exemplary biocide release rates from various enclosure embodiments. [Figure 28B] 1 illustrates exemplary biocide release rates from various enclosure embodiments. [Figure 28C] 1 illustrates exemplary biocide release rates from various enclosure embodiments. [Figure 29] 1 illustrates a cross-sectional view of an enclosure fabric with a biocide coating permeating at least partially into the fabric and its pores. [Diagram 30] FIG. 1 illustrates a perspective view of one exemplary embodiment of an enclosure for protecting a substrate from biofouling that incorporates a wall structure having multiple layers. [Diagram 31] 1 illustrates an alternative embodiment of the enclosure and supplemental pumping system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Although the disclosure of the various embodiments described herein is provided with sufficient specificity to satisfy statutory requirements, these descriptions are not necessarily intended to limit the scope of the claims. The subject matter of the claims may be embodied in a wide variety of other ways, may include different steps or elements, and may be used in combination with other technologies, including past, present, and / or future developments. The descriptions provided herein should not be construed as suggesting any particular order or arrangement among or between the various steps or elements, except when the order of arrangement of the individual steps or elements is explicitly described.

[0048] Disclosed herein are various easy to assemble and / or use enclosures and / or other devices that may be placed in close proximity to, around, in, over and / or under substrates or other objects located in (or disposed within) aqueous environments or aqueous holding tanks susceptible to biofouling. In various embodiments, systems, devices and methods are disclosed that may protect submerged and / or partially submerged substrates or other objects (or portions thereof) from the effects of aqueous biofouling, including the formation and potential retention of biofouling resistance by the substrate for some period of time after the enclosure may be opened and / or removed.

[0049] In various embodiments, protective enclosures are disclosed that may be formed from relatively inexpensive and readily available materials such as polyester, nylon or rayon fabrics, and / or natural materials such as cotton, linen or burlap (or various combinations thereof). In various embodiments, the enclosure may include disposable and / or biodegradable features that allow the enclosure or portions thereof to detach, decay and / or otherwise deteriorate from the substrate and / or support structure after a certain amount of exposure to an aqueous environment, including deterioration and / or peeling after formation of a desired biofilm or other layer on the substrate.

[0050] In various embodiments disclosed herein, the terms "distinct aqueous environment" and / or "local aqueous environment" are meant to broadly encompass some and / or all of the aqueous area in which the chemical composition of the water has been or will be altered due to the influence and / or presence of the enclosure, and may include one or more (and / or any combination thereof) of: 1) any water inside the interior walls of the enclosure (i.e., an "enclosed" or "distinct" aqueous environment); 2) any water in any pores or spaces between the interior and exterior surfaces of the enclosure (i.e., an "entrained" aqueous environment); and / or 3) any water immediately adjacent to the exterior surface of the enclosure (i.e., a "proximal" aqueous environment).

[0051] In some embodiments, the enclosure may substantially surround and / or include the exterior surface of the substrate, while in some alternative applications the enclosure may desirably be positioned and / or configured to protect a substrate located adjacent to and / or outside the enclosure, and an "open aqueous environment" may be considered to be located within the enclosure, and an "enclosed" or "distinct" aqueous environment may be located between the exterior walls of the enclosure and the interior walls of the substrate. For example, in a water tank, the interior walls of the tank may constitute the "substrate" to be protected, and some or all of the water pumped into the tank (i.e., from an external environmental source such as a stream, lake, harbor, or reservoir) may constitute the "open aqueous environment" in which the substrate is sought to be protected. In such cases, an enclosure as described herein may be positioned around the water inlet (or the enclosure walls may be positioned at some point between the water inlet and the tank wall), with the enclosure desirably creating "different" environmental condition(s) in close proximity to the tank wall, thereby protecting the tank wall from the various effects of biofouling as described herein.

[0052] In a similar manner, for embodiments potentially involving "filtering" and / or "straining" of liquids using the enclosure and / or portions thereof, the "open aqueous environment" may be considered to be the upstream source of aqueous water (or other liquid) prior to passing through the enclosure wall, and the "distinct aqueous environment" may be considered to be the liquid after passing through the enclosure portion(s). At least one alternative embodiment may include an enclosure element that may line the interior wall of a water tank, holding cell, or dispensing unit.

[0053] In various alternative embodiments, it should be understood that "enclosing" a substrate as described herein encompasses partially enclosing the substrate with an enclosure to an extent sufficient to induce some and / or all of the desired filtration and / or changes in the chemical composition of the water proximate to the protected substrate, and includes enclosures that do not completely seal or isolate the substrate from the surrounding aqueous or other environment. For example, an enclosure protecting the hull of a boat or ship or other submerged and / or partially submerged portion may be considered to "enclose" the hull as described herein, even if the enclosure only encompasses some or all of the underwater portion of the hull, and portions of the enclosure may be open to the surrounding air (i.e., including portions open to the "above water" environment), may be open to portions of the aqueous environment, and / or may be open to other objects, such as wooden structures, rock walls, solid metal sheets, etc. In a similar manner, an enclosure having various breaks, openings, seams, cracks, crevices, and / or missing wall elements may be considered to "enclose" a substrate as described herein if sufficient enclosure structure is present to desirably induce some and / or all of the desired water chemistry changes and / or filtration functions to occur in proximity to the enclosure and / or protected substrate, thereby protecting the enclosure and / or substrate from biofouling and / or reducing the amount of biofouling of the enclosure / substrate to an acceptable level and / or inducing the formation of a desired biofilm on the substrate as described herein.

[0054] In at least one embodiment, a partially open or skirt-type enclosure is disclosed, such as one having a lower edge of the enclosure wall adjacent and / or in contact with the bottom surface of the harbor floor. In at least one possible embodiment, the enclosure may include features that partially and / or completely "seal" a portion(s) of the enclosure against other objects, such as seawalls, ship hull sections, larger ship hulls, submerged and / or partially submerged structures, and / or the bottom surface / mud of the seabed. In other embodiments, the enclosure may desirably include sufficient depth to provide the biofouling protection described herein, but will be shallow enough to avoid touching the bottom of the aqueous medium at low tide (i.e., e.g., 3 feet long, 6 feet and / or 9 feet underwater depth). If desired, the bottom portion of the vertically oriented sheet may include fenestration, slits, fringes and / or perforations that inhibit, but do not completely prevent, the flow of water into and / or out of the space between the bottom of the enclosure and the seabed.

[0055] In various embodiments, a skirt-type protective system may include individual elements of an enclosure or "skirt" comprising multiple vertically oriented "sheets" or similar structures that may be deployed in the water surrounding an object or portion thereof, with some portions of the sheets extending downwardly below the object to be protected and, in some embodiments, extending into some portion of the euphotic zone (i.e., the sunlit zone) of the body of water, the protective system desirably creating a partial or complete euphotic zone (i.e., a zone that is not sufficiently illuminated) of the water adjacent to the object, or forming a partially or completely bounded region of water that desirably induces and / or maintains a desired change in the chemical composition of the water adjacent the protected object that inhibits biofouling. In various embodiments, the protective system may desirably further induce some degree of permeability change to sunlight passing therethrough, which in some embodiments may reduce and / or prevent the passage of large amounts of usable sunlight (i.e., usable by living organisms) through the top of the enclosure into this low light zone, involving the incorporation of barrier materials such as sheets, meshes, screens and / or other obstructions to reduce and / or eliminate the passage of sunlight (and / or various wavelengths and / or components thereof) between the object and the upper portion of the enclosure wall. In various embodiments, these barrier materials may also inhibit or prevent the physical mixing of oxygen with the water within the barrier due to wave and / or wind action.

[0056] In other embodiments, a skirt or perimeter enclosure may be placed around the perimeter of an offshore oil platform, desirably reducing and / or eliminating biofouling around various portions of the platform's support structure or "legs." In such embodiments, the enclosure walls may be deployed around most of the perimeter of the entire support structure, extending vertically downward into the water from a drum-type dispenser or "float" (or may be fixed directly to the platform and / or to the legs), and the depth of the enclosure wall(s) may be increased and / or decreased as needed. Desirably, the enclosure walls will completely and / or partially surround the platform support (which may include surrounding individual support legs with individual enclosures, or the entire support structure within a single enclosure), and will extend to a depth sufficient to induce a desired change in the water chemistry of portions of the enclosed or bounded body of water, including shallow portions and / or adjacent to the surface of the enclosed or bounded body of water. If desired, one or more of the enclosure walls can be raised and lowered when desired, which can induce a desired change in the chemical composition of the water if the chemical composition of the water is being monitored (i.e., for example, around the rig or at a remote monitoring station). In a similar manner, one or more openings, partitions, and / or partitions within or between the enclosure walls can be opened and / or closed as needed to desirably change the chemical composition of the water in a desired manner.

[0057] If desired, the fouling prevention system may include a free-floating enclosure, with the enclosure walls supported by a floating boom that may surround or encircle the protected vessel. In various embodiments, the disclosed structures and / or components thereof may be attached directly to and / or suspended directly from a dock or boat slip. For example, a U-shaped enclosure may be positioned within a standard boat slip, with the enclosure walls connected to an adjacent dock(es) and / or other structure. If desired, a submerged hanging curtain or other movable wall structure may be provided adjacent the stern of the boat to close the open "U" section, which may be opened and / or closed to allow the boat to enter and exit the dock and / or enclosure. If desired, the hanging curtain may include an underwater wall of the enclosure that may be swung or rotated away from and / or towards the enclosure (i.e., in a manner similar to opening and / or closing a door) to open and / or close the enclosure to allow a boat or other floating structure to enter and / or exit the enclosure. Alternatively, the hanging curtain may incorporate features that allow the curtain and / or portions thereof to be raised and / or lowered to allow a vessel to enter / exit the enclosure in a normal manner (i.e., when the curtain section is lowered a sufficient amount, the vessel may float in and / or out of the enclosure over the lowered curtain section). As another alternative, one or more sections of the enclosure wall material and / or some or all of the support structure(s) (i.e., support pipes or wire cable supports) may "slide sideways" (in a manner similar to opening and / or closing a shower curtain) to allow entry and / or exit of the enclosure. In this embodiment, the upper edge of the enclosure wall may be suspended at least one or two feet above the water surface so that water and / or wave action desirably does not penetrate beyond the top of the enclosure wall (the enclosure desirably extends below the water surface to the desired extent).In various alternative embodiments, the hanging curtains and / or other structures may be attached to various surfaces, including attachment to the protected substrate itself, floating structures, fixed structures, above water surfaces, underwater surfaces and / or the bottom of a body of water and / or subsurface harbor structures and / or on / in the seabed. In some embodiments, direct contact of the enclosure with the seabed may be less desirable where stronger undercurrents and / or excessive siltation may occur, or where undesirable organisms on the seabed may invade and / or attempt to colonize the enclosure components, while in other embodiments, partial and / or complete sealing with the bottom surface (i.e., natural and / or artificial surfaces) may be desirable.

[0058] In various embodiments, the enclosure may be utilized to provide biofouling protection periodically to the protected substrate, which may include interruption of biofouling protection when water flow adjacent to the protected substrate may increase, with biofouling protection potentially resuming during periods when water flow adjacent to the protected substrate is reduced. For example, the enclosure may include one or more subsurface openings, which may be automated and / or controlled by a user, that may be opened when increased water flow into and / or out of the enclosure may be desired. Such occasions may include removal of the substrate from the enclosure, the need for sampling of the water quality of the outside environment, and / or the need for significant levels of cooling and / or other water (e.g., via submerged intakes and / or drains in the substrate's hull). In other embodiments, the enclosure may be designed to provide increased water flow through the enclosure walls for desired periods of time, which may reduce and / or eliminate some or all of the biofouling protection provided by the enclosure during the period(s) of increased flow, but may provide resumption of biofouling protection once the water flow rate is reduced below a predetermined design threshold.

[0059] In at least one exemplary embodiment, the enclosure design may be provided with particular utility as a biofouling prevention and / or filtration system for systems that use seawater and / or freshwater as a cooling water source. In this embodiment, a floating enclosure or "reservoir" in an aqueous environment may be provided, the enclosure containing a much larger amount of aqueous fluid than is required by the cooling system on a normal usage basis. For example, if the cooling system requires 1000 gallons of water per minute during normal operation, the reservoir would desirably contain at least 10,000 gallons, at least 20,000 gallons, at least 50,000 gallons, at least 100,000 gallons, at least 500,000 gallons, and / or at least 1,000,000 gallons and / or more of water. The water inlet, which may desirably be near the top of the reservoir, will draw water having a relatively low dissolved oxygen level into the inlet for use in the cooling device, and water having a relatively high dissolved oxygen level will be drawn into an opening or gap at the bottom and / or any side of the reservoir. During the time it takes for water molecules and / or droplets to pass through the water column in the reservoir, natural and / or artificial oxygen scavengers in the water column will desirably reduce the dissolved oxygen level in the water, so that the dissolved oxygen level is somewhat depleted before moving into the inlet. However, in at least one alternative embodiment, the water inlet may be near the bottom of the enclosure and / or the bottom surface of the reservoir, which is generally the coldest water in the enclosure / reservoir for use in the cooling device.

[0060] In at least one exemplary embodiment, the method for determining the appropriate design, size, shape, and / or other characteristics of the enclosure may desirably be utilized to determine a recommended minimum enclosed or bounded volume and / or water exchange rate to reduce and / or eliminate biofouling within the enclosure. In some embodiments, such as membrane filter configurations where the enclosure may be utilized to provide a cooling water source and / or other source water for a manufacturing plant (i.e., power plants, desalination plants, refineries, and / or other manufacturing facilities), the disclosed methods may potentially be utilized to reduce and / or eliminate biofouling within the water and / or other conduits of the plant, and in some embodiments, without the need for additional filtration and / or microfiltration of the water.

[0061] In various embodiments, the design and use of the enclosure may potentially enhance, induce and / or promote the formation of layers, biofilms and / or material deposits on the substrate and / or enclosure walls under certain conditions, which may reduce, repel, inhibit and / or prevent micro- and / or macro-organisms from subsequently attempting to colonize, recruit and / or foul some or all of the protected substrate (i.e., providing a level of "biofouling inoculum" to the substrate). For example, various embodiments of the enclosure disclosed herein may cause the generation of a unique aqueous environment within the enclosure, resulting in the formation of a unique mixture of microorganisms and / or microflora within that environment, including within one or more aqueous layers proximate the substrate surface. In many embodiments, the unique mixture and / or distribution of microorganisms / microflora within the enclosure may induce and / or induce the formation of a biofilm or other layer of microorganisms on the substrate, which, in combination with various surface bacteria, may release compounds that affect the establishment, recruitment and / or colonization of fouling organisms on the substrate. In various embodiments, once a unique microbial biofilm layer is established, the layer may remain durable and / or self-replenishing, which may continue to protect the substrate from a particular type and / or amount of biofouling for extended periods of time in the absence of the enclosure (i.e., when the enclosure may be temporarily and / or permanently removed and / or damaged).

[0062] In various embodiments, chemicals and / or compounds that affect the settlement, recruitment and / or colonization of fouling organisms on a substrate may include toxins and / or biocides, chemicals and / or compounds that inhibit such settlement, recruitment and / or colonization, chemicals and / or compounds that may lack positive settlement, recruitment and / or colonization cues, and chemicals and / or compounds that may generate lower levels of positive settlement, recruitment and / or colonization cues than are generated on surfaces within the surrounding aqueous environment and / or compared to chemicals and / or compounds that generate positive settlement, recruitment and / or colonization cues for beneficial organisms (e.g., organisms that may not generally be considered significant biofouling organisms). In some embodiments, the lack of certain "welcoming cues" on the protected substrate and / or associated biofilm may provide extended fouling protection to the substrate. In various embodiments, "welcome cues" may include nutrients and / or chemicals that micro- and / or macroflora need, desire, and / or facilitate establishment, recruitment, colonization, growth, and / or replication on a given surface, and such "disinhibitory cues" may include waste metabolites and / or other chemicals that inhibit, inhibit, and / or prevent the establishment, recruitment, colonization, growth, and / or replication of micro- and / or macroflora on a given surface.

[0063] In various embodiments, inhibition of fouling may be represented by a reduction in the total coverage of the substrate and / or enclosure surface(s) / interstices by fouling organisms compared to the total fouling coverage of a substantially similar substrate (without a protective enclosure) submerged and / or partially submerged in a substantially similar aqueous environment. This reduction in fouling may be a 10% or greater reduction in fouling, a 15% or greater reduction in fouling, a 25% or greater reduction in fouling, a 30% or greater reduction in fouling, a 40% or greater reduction in fouling, a 50% or greater reduction in fouling, a 60% or greater reduction in fouling, a 70% or greater reduction in fouling, a 80% or greater reduction in fouling, a 90% or greater reduction in fouling, a 95% or greater reduction in fouling, a 98% or greater reduction in fouling, a 99% or greater reduction in fouling, a 99.9% or greater reduction in fouling, and / or a 99.99% or greater reduction in fouling. Alternatively, inhibition of fouling of the protected article(s) may be expressed as a percentage of the amount of fouling coating and / or fouling mass (i.e., by volume and / or weight) formed on an equivalent unprotected substrate. For example, the protected article may exhibit less than 10% of the fouling coating of the unprotected substrate (such as when the protected substrate exhibits a fouling coating less than 0.1 inches thick and the equivalent unprotected substrate exhibits a fouling coating 1 inch or more thick), which would reflect a greater than 10-fold reduction in the fouling level of the protected substrate and / or enclosure wall compared to the fouling level of the unprotected substrate. In other embodiments, the protected article may exhibit less than 1% fouling, or a greater than 100-fold reduction in the fouling level of the protected substrate and / or enclosure wall. In yet other embodiments, the protected article may exhibit less than 0.1% fouling, which is more than a 1000-fold reduction in fouling levels of the protected substrate and / or enclosure wall.In yet other embodiments of the present invention, the protected substrate and / or enclosure wall may have no visible fouling in any affected area(s) of the substrate and / or enclosure wall, which may represent a fouling level of the protected substrate and / or enclosure of 0.01% (or more) or even 0% (i.e., a reduction in the fouling level of the protected substrate and / or enclosure wall of greater than 10,000 or more) compared to the unprotected substrate. ASTM D6990 and Naval Ships Technical Manual (NSTM) are known reference standards and methods used to measure the amount of fouling percentage range and fouling thickness on a substrate.

[0064] In various additional embodiments, inhibition of fouling may be represented by a reduction in the total increase in coverage of both the substrate and enclosure surfaces by fouling organisms compared to the total increase in fouling coverage of a substantially similar substrate (i.e., without a protective enclosure) immersed and / or partially immersed in a substantially similar aqueous environment, which may be measured by visual inspection, physical measurement, and / or based on the increased weight and / or volume of the combination of substrate and enclosure when removed from the aqueous medium (i.e., the increased weight due to the weight of the fouling organisms attached thereto). The reduction in fouling can be a 10% or greater reduction in fouling, a 15% or greater reduction in fouling, a 25% or greater reduction in fouling, a 30% or greater reduction in fouling, a 40% or greater reduction in fouling, a 50% or greater reduction in fouling, a 60% or greater reduction in fouling, a 70% or greater reduction in fouling, an 80% or greater reduction in fouling, a 90% or greater reduction in fouling, a 95% or greater reduction in fouling, a 98% or greater reduction in fouling, a 99% or greater reduction in fouling, a 99.9% or greater reduction in fouling, and / or a 99.99% or greater reduction in fouling.

[0065] Altered water areas and enclosures FIG. 1 illustrates one exemplary embodiment of an enclosure 10 in the form of a bag or sack having an open proximal end 20 and a closed distal end 30. In use, the enclosure 10 may be placed around a substrate 40, with the open proximal end constructed large enough to pass all around and / or around the substrate and / or any associated support structures, and the open proximal end may be reduced in size, for example, to desirably separate or enclose an aqueous environment within the enclosure (i.e., a "distinct aqueous environment" or "enclosed environment") from the surrounding "open" aquatic environment. For example, a drawstring or pullwire type closure 50 may be used to reduce in size. Desirably, once the enclosure is "separated," "enclosed," or otherwise closed in this manner, some amount of liquid from the open environment may still permeate through the walls of the enclosure into the differentiated environment, and similarly, some amount of liquid from the differentiated environment may still permeate through the walls of the enclosure into the open environment.

[0066] One important feature of the present invention is that while the enclosure may form a "distinct aqueous environment" in close proximity to the substrate, the enclosure also allows for a controlled amount of "mixing" and / or other transport between liquids and / or other materials within the enclosure with liquids and / or other materials in the surrounding aqueous environment (i.e., outside the enclosure). This controlled transport, which may occur both within the enclosure and / or outside the enclosure, desirably creates a unique aqueous environment within the enclosure portion that inhibits and / or prevents significant amounts of biofouling from forming on the substrate. For example, dissolved oxygen in seawater comes from one of three sources: (1) atmospheric oxygen that dissolves, diffuses, and / or mixes into the water surface (i.e., by aeration); (2) oxygen released by algae, submerged plants, and / or other biological processes resulting from photosynthesis or other metabolic pathways; and / or (3) oxygen present in the water flow of streams and rivers that mixes into the seawater. When properly designed and deployed in a suitable environment, the enclosure structure will desirably block and / or inhibit significant amounts of sunlight from penetrating into the differentiated aqueous environment, thereby reducing the amount of dissolved oxygen provided from photosynthesis within the enclosure. In addition, the presence of the enclosure walls will desirably reduce and / or inhibit bulk physical flow of water into, through, and / or out of the enclosure due to horizontal and / or vertical water flow (or a combination thereof) due to various factors, including allowing the enclosure walls to flex to varying degrees and thus provide at least a partial barrier to water flow, while also allowing the enclosure walls to change shape and / or orientation to some significant degree to reduce flow resistance, and reducing pressure differentials driving water flow through the pores of the wall fabric, since flexible enclosure walls may "move" and / or deform with the water flow to varying degrees.

[0067] In at least one exemplary embodiment, when an enclosure of the present invention is initially placed around a substrate, the dissolved oxygen in the differentiated aqueous environment may be quickly depleted from the interior of the enclosure by biological, metabolic, and / or other processes and / or activities within the enclosure to create oxygen-depleted regions within the enclosure. However, because the enclosure allows for some bulk flow of water into and / or out of the enclosure (i.e., water exchange between the enclosure and the surrounding "open" body of water), some amount of oxygen replenishment will occur with the influx of oxygen-saturated water through the enclosure walls, and some amount of oxygen-depleted water will exit through the enclosure walls. In general, oxygen replenishment within the enclosure occurs at a slower rate than is normally utilized by the microflora and / or microfauna of the open water, which induces and / or forces at least a portion of the microflora and / or microfauna within the enclosure to change their activity, behavior, reproduction, metabolism, diversity, composition, and / or relative distribution to adapt to the artificial conditions within the enclosure, as well as affecting various natural chemical processes such as oxidation and / or free radical activity. Furthermore, as the oxygen levels and / or exchange rates of the open water vary due to various factors (day / night cycles, currents / tides, and / or other water movements, aeration of the water due to wind and / or storm activity, etc.), the influx of dissolved oxygen will change, which will change the levels of oxygen and / or other chemicals within the enclosure, which will induce further changes in the activity, behavior, reproduction, metabolism, composition, and / or relative concentrations of the microflora and / or microfauna within the artificial environment inside the enclosure. Desirably, the artificial environmental conditions created by the enclosure will thereby inhibit and / or prevent settlement, recruitment, growth and / or colonization of the substrate by fouling organisms, and will also induce a unique mix of metabolic and / or other processes to occur within the enclosure.

[0068] FIG. 8A illustrates dissolved oxygen levels within various enclosure embodiments submerged in seawater over a period of several months. For each of these embodiments, the dissolved oxygen levels within the enclosure are generally lower than that of the surrounding open water, creating an artificial environment that causes the microflora and / or microfauna within the enclosure to alter their activity, behavior, reproduction, metabolism, diversity, composition, and / or relative distribution to adapt to these artificial conditions. Additionally, the artificial conditions within the enclosure are constantly changing, as shown in FIG. 10A, causing the dissolved oxygen levels within the enclosure (i.e., the lower line labeled "spun poly bag") to "follow" or "lag" behind the changing oxygen levels outside the enclosure.

[0069] In general, a change in the net amount of dissolved oxygen within an enclosure as described herein should be attributable to any inflow of dissolved oxygen contained in the water flowing into the enclosure through the enclosure walls (i.e., typically an increased source of oxygen) minus the amount of oxygen consumed within the enclosure by various processes occurring within the enclosure, including oxidation or similar processes, and / or metabolic processes of the flora and / or fauna therein (i.e., a decreasing oxygen supply) (and to some extent any dissolved oxygen flow of deoxygenated water flowing out of the enclosure). If the external dissolved oxygen level is higher and / or the inflow of water brings more oxygen into the enclosure than is consumed and / or leaves the enclosure, the net oxygen level within the enclosure should increase to some extent, and if the external dissolved oxygen level is lower and / or the inflow of water is slower and brings less oxygen into the enclosure than is consumed within the enclosure, the net oxygen level within the enclosure should decrease to some extent. Thus, the dissolved oxygen levels within the enclosure "respond" or "lag" behind the dissolved oxygen levels of the waters surrounding the enclosure, and the DO levels of the enclosure are typically (but not always) below the DO of the surrounding waters. Moreover, as best seen in Figures 10A and 10B, the DO levels within the enclosure (lower line labeled "spun polybag") often resemble the diurnal and / or seasonal variations in dissolved oxygen outside the enclosure (upper line labeled "open configuration"), although generally at reduced levels. Each of these changes in the differentiated environment will desirably cause the macro- and microflora and / or macro- and microfauna within the enclosure to further alter their activity, behavior, reproduction, metabolism, diversity, composition, and / or relative distribution to adapt to the changes in the artificial conditions.

[0070] In addition to inducing generally lower dissolved oxygen levels than those outside within the enclosure, various embodiments of the present invention may reduce and / or limit the amount of variation between the highest and lowest oxygen levels in the open environment, and additionally have the ability to reduce or "smooth out" many of the temporal variations in oxygen levels that may contribute to fouling in the open environment. Such moderation or smoothing of DO levels within the enclosure can be seen in Figures 10A and 10B, where the variations in dissolved oxygen within the enclosure undergo much smoother changes than those of an open body of water, and the changes in DO levels within the enclosure are moderated or smoothed out compared to the more "jagged" and / or abrupt changes in DO levels of the open environment outside the enclosure.

[0071] In various enclosure embodiments, dissolved oxygen levels within the local aquatic environment will desirably be maintained on average over a 24 hour period or above other dissolved oxygen levels, including concentrations of greater than 5%, or 8%, or 10%, or 12%, or 15%, or 20%, or 25%, or 50%, or 60%, or 75%, or 80%, or 85%, or 90%, or 100%, or 105%, or 110%, or 115%, or 120%, or 125%, or greater than 15%, greater than 14%, greater than 13%, greater than 12%, greater than 11%, greater than 10%, greater than 9%, greater than 8%, greater than 7%, greater than 6%, greater than 5%, greater than 4%, greater than 3%, greater than 2%, greater than 1%, and / or greater than 0% dissolved oxygen. However, in some embodiments, it may be acceptable and / or even desirable for the dissolved oxygen levels within the enclosure to be reduced to anoxic levels, which may include oxygen concentrations of less than 0.5 milligrams of oxygen per liter of liquid in some or all of the enclosure. Such anoxic conditions desirably will not be maintained for extended periods of time, but rather tend to be a relatively temporary phenomenon having a duration of less than 1 minute, or less than 10 minutes, or less than 30 minutes, or less than 1 hour, or less than 3 hours, or less than 12 hours, or less than 24 hours, or less than 1 week, depending on the associated enclosure design, local water conditions, substrates to be protected, associated season(s), local fouling pressures, and / or other factors. Desirably, such reduced and / or anoxic oxygen levels will not be maintained for periods of time that are significantly detrimental to the underlying substrate and / or structure of the enclosure.

[0072] The reduced dissolved oxygen levels created within the enclosure are believed to contribute significantly to the reduction of biofouling of the substrate in that the reduced availability of oxygen may make it difficult for some fouling organisms to colonize and / or reproduce within the enclosure and / or on the substrate. In addition, the reduction of dissolved oxygen levels within the enclosure may increase the formation of waste products such as hydrogen sulfide and / or ammonia nitrogen (i.e., free ammonia nitrogen, nitrogen-ammonia or NH3-N) and / or may significantly reduce the opportunity for other organisms to process and / or eliminate such waste products, both of which are harmful and / or even toxic to various aquatic organisms and / or microorganisms. For example, FIG. 12A illustrates the biologically conducted nitrogen cycle that occurs naturally in various water bodies, which may contribute significantly to the reduction of free oxygen within the enclosure, and FIG. 12B graphically illustrates an exemplary dependence of NH3-N on available dissolved oxygen levels. Additionally, in some embodiments, anaerobic ammonia oxidation reactions may potentially be initiated and / or sustained by bacteria within the enclosure, which may produce hydrazine and / or other by-products that also inhibit marine growth. Generally, the concentrations of these by-products will be higher inside the enclosure than outside the enclosure (although various of these harmful compounds, including various known and / or unknown microbial "toxins" and / or inhibitory compounds, may elute through the enclosure walls at different rates), and in some embodiments, the individual concentrations and / or comparative ratios of these by-products within the enclosure may vary for a variety of reasons.

[0073] For example, in various embodiments, the enclosures described herein may induce the formation of metabolic waste products, toxins, or other inhibitory compounds such as NH3-N at concentrations ranging from 0.53 mg / L to 22.8 mg / L within the enclosure, which may be toxic to various freshwater organisms (typically pH and / or temperature dependent). In other embodiments, the concentration of NH3-N generated within the differentiated environment within the disclosed enclosure may range from 0.053 to 2.28 mg / L, which may inhibit biofouling formation within the enclosure and / or on the exterior surface of the enclosure. Additionally, at levels of NH3-N as low as 0.002 mg / L or greater, the ability of various aquatic flora and / or fauna to colonize and / or reproduce may be significantly reduced.

[0074] In some exemplary embodiments, it is further proposed that fluctuations and / or changes in the individual levels of the chemical composition components of the water within the enclosure, such as dissolved oxygen, ammonium, total dissolved nitrogen, nitrate, nitrite, orthophosphate, total dissolved phosphate, and / or silica (as well as various other chemical components described herein), form an important aspect of some embodiments of the present invention in that the artificial environment created within the enclosure will desirably "promote" and / or "inhibit" the proliferation of different macrofouling and microflora and / or macrofouling and microfauna at different time periods. Such continuous changes in the differentiated environments desirably cause the various organisms present within and / or adjacent to the enclosure to constantly adapt and / or change to accommodate new environmental conditions, which tends to inhibit the dominance of a single species or grouping of species within and / or adjacent to the enclosure. This can have the effect of enhancing competition between the various flora and / or fauna within the enclosure, which can inhibit and / or prevent domination of the enclosure by a single species, species, and / or distribution of flora and / or fauna, thereby reducing the potential for a dominant species of bacteria or other micro- or macro-entity to thrive and / or have the opportunity to expend energy fouling the substrate or form a base onto which other fouling organisms can attach.

[0075] In various embodiments, the enclosure may induce the formation of a water chemistry factor that inhibits fouling, such as ammonia nitrogen, at a higher concentration within the enclosure than outside the enclosure. If desired, a concentration of ammonia nitrogen within the enclosure may be obtained, which may be 0.1 parts per billion (ppb) or more, 1 parts per billion (ppb) or more, 10 parts per billion (ppb) or more, and / or 100 parts per billion (ppb) or more. In various embodiments, the enclosure may induce the formation of a water chemistry factor that inhibits fouling, such as nitrite, at a higher concentration within the enclosure than outside the enclosure. If desired, a concentration of nitrite within the enclosure may be obtained, which may be 0.1 parts per billion (ppb) or more, 0.1 parts per million (ppm) or more, 0.5 parts per million (ppm) or more, and / or 1 parts per million (ppm) or more.

[0076] Another important aspect of the enclosure of many embodiments of the present invention is that the enclosure desirably inhibits, but does not completely prevent, the flow of water into and / or out of the enclosure under typical water conditions. Often, the substrate to be protected is secured, connected, attached, and / or tethered to one or more solid, immovable objects, such as the ocean floor, anchors, walls, piers, pilings, quays, wharves, and other structures that may constrain the substrate's movement to various degrees relative to the water in which it is placed, which may induce some level of bulk water flow past the substrate's various surfaces. However, the various embodiments of the enclosure described herein (typically attached to the substrate, its various support structures, and / or other adjacent objects) will desirably interrupt and / or impede the ambient flow of water immediately adjacent to the substrate surface to some degree, and more desirably maintain the enclosed or bounded body of water in direct contact with the substrate under many water flow conditions. The various enclosure designs disclosed herein achieve this goal through the flexibility of the various enclosure components, which allows the enclosure and the body of water enclosed or bounded therein to deform and / or displace to different degrees in response to impact and / or movement of the surrounding body of water.

[0077] If desired, the enclosure may be formed into a shape that approximates the size, shape, and / or general contour of the substrate (or portion thereof) to be protected, such as a bladed bag shape (see FIG. 1) for protecting one or more individual propeller blades, or a cylindrical or non-cylindrical "bag" shape 150 (see FIG. 2), which may include a flexible wall 152, a bottom cap 153, and / or a top end cap 154 ​​that substantially encloses the substrate 159 (i.e., a sensor or other structure) as shown. FIG. 2 also illustrates a support 156 that supports and / or substantially isolates the substrate 159 from the inner walls of the enclosure and / or end caps, with the enclosure assembly attached to a rope or tether 158. If desired, such enclosure designs may be utilized to protect girders, supporting cables or ropes, and / or cylindrical sensors or sensor supports. In various embodiments, the enclosure may include one or more substantially flexible curved walls, which may optionally incorporate few or no macroscopic exterior-facing corners, "sharp" depressions, and / or exteriorly oriented gaps that may be particularly hospitable to biofouling organisms. In various designs, the exterior-facing walls of the enclosure are desirably flexible, including the side structures and, optionally, the surfaces facing the top and / or bottom of the enclosure. In various embodiments, enclosures of virtually any shape, size, and / or configuration may be provided, including enclosures that are "prefabricated," as well as enclosures having prefabricated or modular subsections that can be assembled into a final enclosure of a desired size, shape, and / or configuration, etc. If desired, the enclosure may be designed in a relatively simple shape to accommodate a substrate having a highly complex shape (i.e., a valve, a perforated substrate, or a sensor), or the enclosure may be designed in a relatively complex three-dimensional shape to accommodate a substrate having a highly simplified external shape.

[0078] In various embodiments, it may be desirable for the permeable walls of the enclosure to remain spaced apart from the surface of the substrate, while in other embodiments, occasional, periodic, and / or constant contact between portions of the enclosure and various surfaces of the substrate may provide little or no modification of the biofouling protection provided thereby. In still other embodiments, occasional, periodic, and / or constant contact between portions of the enclosure and various surfaces of the substrate may provide significant improvement in the biofouling prevention effectiveness of the enclosure. In some embodiments, the enclosure walls may be in direct contact with the protected substrate, such as when a fibrous substrate may be wrapped around a substrate such as a submerged and / or partially submerged pipe, girder, and / or stake.

[0079] In various embodiments as shown in FIG. 3, the enclosure 310 may include one or more gapped or spaced apart sections 325 (i.e., spaced apart from the substrate 300), including a portion located proximate the bottom or lower portion 340 of the substrate 300, which may provide additional space within the enclosure for sediment 320 and / or other matter that resides or collects in a differentiated environment without permanently remaining in direct contact with the substrate (i.e., leaving the "space" 330 between the sediment and the substrate). Such sediment(s) may include dead, dying, and / or decaying bodies of microorganisms that may not exit through openings within the enclosure, which may result in a "pile" and / or "mud" of sediment that gradually rises within the enclosure. If desired, the openings in the enclosure in such "lower areas" may be made larger and / or more numerous than corresponding openings in other areas of the enclosure, desirably to allow such sediment or other material to pass through and / or drain from the enclosure over time, and to allow incoming / outgoing liquid or water currents to "flush" the sediment out of the enclosure in a controlled manner. In other embodiments, the openings in the enclosure in such "lower areas" may be made smaller and / or less numerous to minimize water exchange due to "upwelling" and / or "downwelling" plumes of water that may be caused by local temperature fluctuations, or may be increased in number and / or size to allow additional water exchange in certain circumstances, if desired.

[0080] In various descriptions of the present disclosure, "permeability" is desirably utilized as an indication of some aspects of the enclosure and / or its components, since it may be somewhat difficult to measure and / or determine the "effective" porosity of the entire opening of the spun poly and / or burlap material due to the "fuzziness" and / or randomness in the architecture of this fabric, which may be compounded by changes in the flexibility and / or morphology of the fabric in wet and / or dry conditions, and which applicant believes may be optionally important to the effectiveness of various embodiments of the disclosed systems and devices. In various embodiments, the enclosure may include one or more walls comprising a flexible material, with openings and / or pores formed therethrough. In some desirable embodiments, some or all of the openings through the wall(s) may include a tortuous or "curvy" flow path, with the tortuosity being the ratio of the actual length of the flow path (L) to the linear distance between the two ends of the flow path. t ) is defined as:

number

[0081] In one exemplary embodiment, woven fabrics made from textured or spun polyester yarns may be highly desirable for use in making the exemplary enclosure wall, with spun polyester yarns potentially having a significant number of fiber ends extending from the yarn in various locations (i.e., relatively high levels of "hairiness" or pilus) and in multiple directions, desirably leading to a more complex three-dimensional macrostructure and / or a more tortuous path(s) from the exterior surface to the interior surface of the fabric. In various preferred embodiments, these fiber ends may extend into natural openings that may be present in the woven fabric, potentially reducing and / or eliminating some "straight path" openings through the fabric and / or increasing the tortuosity of existing paths through the fabric (which may extend a significant distance through the topography of the three-dimensional fabric in some cases). In various embodiments, it may be desirable for portions of the fabric to incorporate openings with a tortuosity ratio of greater than 1.25, while in other embodiments, a tortuosity ratio of greater than 1.5 may be more desirable for various openings in the fabric.

[0082] FIG. 4A illustrates one exemplary scanning electron microscope (SEM) micrograph of an exemplary spun yarn 400, illustrating a central body or yarn bundle 410 of intertwined filaments 420 with various filament ends 430 extending transversely to the central body 410. FIG. 4B illustrates a cross-sectional view of the central body 410, highlighting the very fine size of the individual filaments 420 within the yarn bundle 410. As best seen in FIG. 4C, which illustrates a close-up view of a knitted fabric 450 including PET spun yarn, a series of gaps or openings 480 are positioned between the yardage bundles 470 during the knitting process, with one or more extending fibers or fiber ends 490 extending across the various openings (with multiple fiber ends desirably traversing each opening in various embodiments).

[0083] In various embodiments, the enclosure walls and the substrate(s) protected therein may be separated and / or spaced apart by an average distance (i.e., between the inner wall of the enclosure and the outer surface of the substrate) of about 200 inches, or about 150 inches, or about 144 inches, or about 72 inches or less, or about 36 inches or less, or about 24 inches or less, or about 12 inches or less, or about 6 inches or less, or about 1 inch or less, or about 1 inch or more, or about 6 inches or more, or about 1 inch to about 24 inches, or about 2 inches to about 24 inches, or about 4 inches to about 24 inches, or about 6 inches to about 24 inches, or about 12 inches to about 24 inches, or about 1 inch to about 12 inches, or about 2 inches to about 12 inches, or about 4 inches to about 12 inches, or about 6 inches to about 12 inches, or about 1 inch to about 6 inches, or about 2 inches to about 6 inches, and / or about 4 inches to about 6 inches. In various alternative embodiments, at least some or all of the enclosure may be in direct contact with the substrate in one or more areas (including but not limited to, closed portions of the enclosure), and thus, in some embodiments, there may be substantially little or no distance between the structure and the substrate.

[0084] In various other embodiments, it may be desirable for the spacing between the enclosure wall and the substrate to fall within a particular range of average distances, or the desired spacing may be proportional to the width, length, depth, and / or other characteristics of the enclosure and / or substrate to be protected. For example, maintaining a predetermined spacing between a smaller substrate and a smaller enclosure containing only a few gallons of water may be more important compared to spacing between a relatively large hull and a large enclosure containing thousands or millions of gallons of water in its "separate environment" within the enclosure, especially when there is a relatively small amount of water in the differentiated environment that may be more susceptible to changes in water exchange levels and the resulting water chemistry thereto. In such cases, the desired spacing between the enclosure walls and the opposing surface of the substrate may be 2% or less of the distance between the opposing enclosure walls, 5% or less, or 10% or less, or 20% or less, or 30% or less, or 40% or less, or up to 49.9% of the distance between the opposing enclosure walls, depending on the substrate size, type, enclosure design, and / or enclosure stiffness, and / or design. In another embodiment, the localized aqueous environment may extend a distance in a direction away from the surface of the substrate of 100 inches or more, 50 inches or more, 10 inches or more, 5 inches or more, 3 inches or more, 2 inches or more, 1 inch or more, 0.5 inches or more, 0.1 inches or more, 0.04 inches or more, 50 feet or less, 40 feet or less, 20 feet or less, 20 feet or less, 10 feet or less, 4 feet or less, 2 feet or less, 100 inches or less, 10 inches or less, 5 inches or less, 1 inch or less, 0.1 inches or less, 0.04 inches or less.

[0085] FIG. 5 illustrates an exemplary fabric material 100 in rolled sheet form that may be used in various ways to form the various enclosures described herein. In this embodiment, the material desirably comprises a fabric material that may include flexible fibrous materials, in this case natural fiber fabrics, as well as woven, knitted, felted, nonwoven and / or other structures of polyester or other synthetic fibers, and / or various combinations thereof. In various embodiments, the fabric may be utilized to construct the various enclosure embodiments described herein, and / or it may be possible and / or desirable to use such rolled sheet material to roll or otherwise "cover" an elongated substrate, particularly where the unrolled and unwrapped sheets may overlap other sheet sections (i.e., along stakes or support girders) that may create an "enclosure" that includes the progressively wrapped substrate, the fabric material wrapped around the substrate in an overlapping "barber pole" or maypole type technique, or to line the interior walls of a water tank or irrigation pipe. In such cases, it may be desirable for the fabric to be in direct contact with the protected substrate, with a very thin layer of liquid between the fabric enclosure walls and the substrate surface (and optionally liquid within the fabric itself) constituting the "distinguished environment" described herein.

[0086] In various alternative embodiments, the enclosure and / or its component materials may include three-dimensional fabric substrates and / or fibrous substrate structures fashioned from interwoven and / or intertwined strands of sewing threads formed in a lattice, mesh, mat, or fenestrated fabric arrangement, and in various embodiments may incorporate one or more non-flat and / or non-smooth fabric layer(s). In one overly simplified form, the enclosure may contain a plurality of horizontally positioned elements interwoven with a plurality of vertically positioned elements (as well as various combinations of other fibrous elements aligned in various directions), which may include a plurality of separate and / or interwoven layers. The flexible material may include one or more spaced apart layers, which may include baffles or various interconnecting sections. Desirably, each thread or other sewing element(s) within the envelope material will include a preselected number of individual strands, at least a portion of which extend outward from the sewing core element in various locations and / or directions, thereby creating a three-dimensional, serpentine network of sewing threads and sewing strands interwoven into the fabric. In various embodiments, the various elements of the fibrous substrate may be aligned in virtually any orientation, including diagonally, or in a parallel manner relative to one another, thereby forming right angles, or in virtually any other orientation, including three-dimensional orientations, and / or randomized distributions (i.e., felted mats) and / or patterns. In addition, in some embodiments, there may be significant spacing between the individual elements, while in other embodiments, the spacing may be reduced to a very tight pattern to form a tight pattern with little or no spacing between them. In various preferred embodiments, elements such as sewing threads and / or fibers may be made of natural or synthetic polymers, but may also be made of other materials, such as metal, nylon, cotton, or combinations thereof.

[0087] Various embodiments of the present invention may include the use of highly ciliated fibrous substrates and / or flexible materials, meaning that the material may include tendrils or hair-like appendages (i.e., fibers) that protrude from its surface or into the pores, or open spaces of the three-dimensional flexible fabric that forms the "filtration" medium. The tendrils or hair-like appendages may be part of or incorporated into the material that constitutes the three-dimensional flexible filtration material. Alternatively, the tendrils or hair-like appendages may be formed from a separate composition that is adhered or attached to the flexible material. For example, the tendrils or hair-like appendages may be attached to and protrude from an adhesive layer that is itself attached to the surface of the flexible material. In embodiments of the present invention, the tendrils or hair-like appendages may protrude from the surface of the enclosure material, while in other embodiments, the tendrils or hair-like appendages may extend inwardly from the enclosure material and / or toward and / or into other threads and / or fibers of the fibrous substrate and / or fabric of the enclosure material. In various aspects of the invention, the tendrils or hair-like appendages may be elastic and / or may vibrate and / or sway due to the movement of the enclosure and / or water. In various embodiments, the combination of the movement of the cilia themselves and / or the tendrils or hair-like appendages may also cause the establishment of biofouling organisms on or within the surface of the enclosure to be abandoned.

[0088] The presence of many small fibers in the permeable material of the enclosure can provide a significant increase in the complexity of the three-dimensional structure of the material, as these structures can extend into and / or around the open interstices of the woven pattern. This arrangement of fibers can further provide a more tortuous path for organisms attempting to traverse the depth of the fabric and enter the interior environment protected by the enclosure (i.e., improving the "filtering" effect of the material). In various embodiments, it has been determined that spun polyester has highly desirable properties as an enclosure material. In various embodiments, the shape and / or size of the three-dimensional "entry path" into the enclosure (i.e., as the microorganisms pass through the openings and / or pores of the material) will desirably provide a longer path, a larger surface area, and / or will prove more effective in filtering and / or impeding the influx of fouling organisms into the enclosure.

[0089] In various embodiments, the three-dimensional topography of the enclosure wall will desirably contribute to the anti-biofouling effectiveness of the enclosure in that such fabric construction may improve the "filtration effectiveness" of the enclosure wall and / or may adversely affect the ability of various fouling organisms to "cling" to the enclosure fabric and / or the protected substrate. However, in other embodiments, the enclosure wall and / or other components may include "flatter" and / or "smoother" materials such as textured yarns or other materials (and / or other material construction techniques) and still provide many of the anti-biofouling benefits disclosed herein. Such materials may be significantly flatter, smoother, and / or less ciliated than materials incorporating spun polyester yarns, while still providing acceptable levels of biofouling protection for various applications.

[0090] Various materials that may be suitable to various degrees for constructing the enclosure include various natural and synthetic materials, or combinations thereof. For example, jute, jute, canvas, wool, cellulose, silk, cotton, hemp, and muslin are non-limiting examples of possible useful natural materials. Useful synthetic materials may include, without limitation, the polymer classes of polyolefins (polyethylene, ultra-high molecular weight polyethylene, polypropylene, copolymers, etc.), polyester, nylon, polyurethane, rayon, polyamide, polyacrylic, and epoxy. Various types of glass fiber compositions may also be used. Combinations of polymers and copolymers may also be useful. These three-dimensional flexible materials may be formed into fibrous structures, permeable sheets, or other configurations that provide structures that can provide anti-fouling and / or filtration properties as described herein. Examples of potentially suitable flexible materials for use in constructing the enclosures described herein include, but are not limited to, jute, canvas, cotton, linen, muslin, permeable polymer sheets, fabrics constructed from polymer fibers or filaments, and permeable films and membranes. In embodiments of the invention, the flexible material may be selected from natural or synthetic fabrics such as jute, knitted polyester or other fabrics, woven polyester or other fabrics, spun polyester or other fabrics, various combinations thereof, or other fabrics having various properties, including those shown in Figures 19, 27A, 27B, and Tables 3, 4A, 4B.

[0091] In various embodiments, the flexible material forming one or more walls of the enclosure may have a structure formed by intertwined fibers or bundles of fibers (i.e., threads). As used herein, "intertwined" means that the fibers may be nonwoven, woven, knitted, braided, or otherwise interwoven to produce a fibrous matrix capable of various filtration and / or water permeability and / or water exchange characteristics as discussed herein. The material in which the fibers are intertwined may desirably create a pattern of open and closed spaces in the three-dimensional flexible material, in which the open spaces define interstices. Desirably, the fibers that may make up the flexible material may be, for example, a single filament, a bundle of multiple filaments, a filament of natural or synthetic composition, or a combination of natural and synthetic compositions. In aspects of the invention, the fibers have an average diameter (or "average filament diameter") of about 50 mils or less, about 25 mils or less, about 10 mils or less, about 6 mils or less, about 5 mils or less, about 4 mils or less, about 3 mils or less, about 2 mils or less, about 1 mil or less, about 0.5 mils or less, about 0.4 mils or less, about 0.3 mils or less, about 0.2 mils or less, or about 0.1 mils or less.

[0092] In some embodiments of the invention, the flexible material may comprise a woven or knitted fabric. For example, the woven fabric may have a picks per inch ("ppi" or weft per inch) of about 3 to about 150, about 5 to about 100, about 10 to about 50, about 15 to about 25, about 20 to about 40, and / or about 20 ppi. In other embodiments of the invention, the woven fabric may have a picks per inch ("epi" or warp per inch) of about 3 to about 150, about 5 to about 100, about 10 to about 50, about 15 to about 25, about 20 to about 40, and / or about 20 epi or about 24 epi. In still other various other aspects of the invention, the knitted fabric may have courses per inch ("cpi") of about 3 to about 120, about 5 to about 100, about 10 to about 50, about 15 to about 25, about 20 to about 40, and / or about 36 cpi or about 37 cpi. In still other aspects of the invention, the knitted fabric has wales per inch ("wpi") of about 3 to about 80, about 5 to about 60, about 10 to about 50, about 15 to about 25, about 20 to about 40, and / or about 36 wpi or about 33.7 wpi.

[0093] Thus, in at least one embodiment of the present invention, the woven fabric has a yarn size density (i.e., warp yarns multiplied by weft yarns per unit area) of about 9 to about 22,500, about 100 to about 20,000, about 500 to about 15,000, about 1,000 to about 10,000, about 2,500 to about 8,000, about 4,000 to about 6,000, about 2,500 to about 4,000, about 5,000 to about 15,000, about 10,000 to about 20,000, about 8,000 to about 25,000, about 20 to about 100, about 30 to about 50, about 45, or about 40 threads per square inch.

[0094] In another embodiment of the invention, the yarns of the woven or knitted fabric have a size of about 40 denier to 70 denier, about 40 denier to 100 denier, about 100 denier to about 3000 denier, about 500 to about 2500 denier, about 1000 to about 2250 denier, about 1100 denier, about 2150 denier, or about 2200 denier.

[0095] In yet another embodiment of the invention, the woven or knitted fabric has a basis weight per unit area of ​​about 1 to about 24 ounces per square yard (about 34 to about 814 g / m2), about 1 to about 15 ounces per square yard, about 2 to about 20 ounces per square yard (about 68 to about 678 g / m2), about 10 to about 16 ounces per square yard (about 339 to about 542 g / m2), about 12 ounces per square yard (about 407 g / m2), or about 7 ounces per square yard (about 237 g / m2), or about 3 ounces per square yard. In another embodiment of the invention, a woven fabric based on desirable spun polyester fibers may be utilized as the enclosure material, the fabric having a basis weight per unit area of ​​about 410 grams per meter. 2 (See Table 13)

[0096] In various exemplary embodiments, suitable enclosure or structural wall thicknesses may range from 0.025 inches to 0.0575 inches or more, with desirable enclosures being approximately 0.0205 inches thick, approximately 0.0319 inches thick, approximately 0.0482 inches thick, and / or approximately 0.0571 inches thick. Depending on the size of the perforations and / or openings in the enclosure, and the shape, size, and / or tortuosity of the various openings in the enclosure, enclosures of greater and / or lesser thickness than those specifically illustrated may be utilized with varying degrees of success and various enclosure designs with various enclosure materials. In various alternative embodiments, the flexible base materials, fibers, and / or threads utilized in the construction of the disclosed fibrous matrices may have wide variations in thickness and / or length, depending on the desired substrate or particular application to be protected. For example, in some embodiments of the invention, the thickness of the flexible material can be about 0.001 to about 0.5 inches, about 0.005 to about 0.25 inches, about 0.01 to about 0.1 inches, about 0.02 inches, about 0.03 inches, about 0.04 inches, about 0.05 inches, or about 0.06 inches. Thickness and permeability variations within a single structure, such as a membrane filtration structure, and multiple layers thereof, are contemplated.

[0097] It should be understood that a wide variety of materials and / or combinations of materials may be utilized as the enclosure material to achieve the various objectives described herein. For example, films or similar materials may be utilized as one alternative to fabric enclosure wall materials, which may include permeable and / or impermeable films for some or all of the enclosure walls. Similarly, natural and synthetic materials such as rubber, latex, thin metals, metal films, and / or foils, and / or plastics or ceramics may be utilized with varying results.

[0098] FIG. 30 illustrates a perspective view of one exemplary embodiment of an enclosure 3000 for protecting a substrate from biofouling that incorporates a wall structure having multiple layers, which may include a wall structure incorporating multiple layers having the same, similar or different permeabilities for each layer, the same, similar or different materials for each layer, and / or the same, similar or different thicknesses for each layer. In another embodiment, the layers may be spaced apart with minimal or no spacing between each layer, or with significant spacing between each layer. If desired, the first top layer 3010 may be removable, such that removal of the first top layer (which may include a "peel back" or other type of connection section 3015) exposes an intact second bottom layer 3020, removal of the second bottom layer exposes an intact third bottom layer (not shown), and so on, all surrounding a protected substrate. If desired, the first top layer may be removable, with the remaining bottom layer(s) remaining intact around the substrate, and then a replacement first top layer may be positioned around the intact bottom layer(s) and / or substrate, such as when the first top layer becomes sufficiently contaminated to justify removal and / or replacement. Alternatively, multiple top and / or bottom layers may include multiple sacrificial layers, each of which, when sufficiently contaminated, is removed to expose the underlying virgin or semi-virgin layers (i.e., still surrounding and protecting the substrate). In some embodiments, the bottom layer may remain in position around the substrate for an extended period of time, even 1, 2, 3, 4, and / or 5 years or more, with periodic removal, replacement, and / or renewal of the outer layers around the substrate and / or bottom layer(s) (i.e., removal of contaminated layers and immediate and / or delayed replacement with new top layers), as described above. Such systems may have application in salt water, fresh water, and / or brackish water, if desired.

[0099] In various embodiments, the enclosure design may incorporate permeable walls of various configurations, including: (1) an enclosure that completely surrounds the substrate (i.e., a "box" or "flexible bag" enclosure); (2) an enclosure with side walls that surround the perimeter of the substrate (i.e., a "skirt" or "drape" that surrounds the sides of the substrate but may have an open top and / or bottom); (3) an enclosure formed from modular walls that may be assembled around the substrate, which may incorporate various openings and / or missing modular sections (i.e., an "open geodesic dome" enclosure); (4) an enclosure that surrounds only the immersed portion of the substrate (i.e., a "floating bag" enclosure that is open at the top); and / or (5) an enclosure that protects only a single side of the substrate (i.e., a "drape" enclosure), as well as many other potential enclosure designs. In addition, the enclosure walls may be relatively smooth or flat, or curved and / or continuous, or, if desired, the enclosure walls may include highly complex structures such as undulating surfaces, corrugated or accordion-like surfaces, folded, "crinkled" or "squashed" surfaces, and / or other features that may dramatically increase the surface area and / or potentially alter the filtering capabilities of the enclosure walls.

[0100] In various embodiments, the enclosure may incorporate one or more walls comprising a three-dimensional flexible filtration fabric comprising fiber filaments and having an average base filament diameter of about 6 mils or less (i.e., 0.1524 millimeters or less). In various alternative embodiments, the enclosure material may comprise textured polyester. In addition, natural fiber materials such as 80×80 burlap may be useful in protecting substrates as enclosure materials and may be useful in various aqueous environments, even when the natural materials degrade relatively quickly in aqueous environments and the underlying decomposition process contributes to significant measurable pH differences within the enclosure. If desired, various enclosure embodiments may incorporate degradable and / or hydrolyzable materials and / or bonds (i.e., between components and / or along the polymer chains of the component materials) that allow the enclosure components to degrade in aqueous media after a period of time.

[0101] In various embodiments, the devices of the present invention will desirably provide for the formation of a desired enclosed environment that, when deployed, initiates the formation of a desired localized aqueous environment (i.e., a "differentiated environment") that reduces, stops, and / or reverses biofouling protection and / or inhibits the establishment of biofouling organisms and / or encourages the formation of a desired anti-biofouling layer and / or biofilm on the substrate, i.e., induces the formation of a favorable biofilm resulting in reduced biofouling on the protected substrate or article. In various embodiments, this "differentiated environment" can be formed within minutes or hours of deployment of the enclosure around the substrate, while in other embodiments, it can take days, weeks, or months to form the desired "differentiated environment." If desired, the enclosure can be deployed well before the substrate is placed therein, while in other embodiments, the enclosure can be deployed simultaneously with the substrate, or the enclosure can be deployed well after the substrate has been submerged and / or maintained in an aqueous environment. In various embodiments, the formation of significant water chemistry differences and / or other unique aspects of the differentiated environment may begin to form within one hour of the enclosure being placed in the aqueous environment (which may include the enclosure being placed alone in the environment and / or in proximity to the substrate to be protected), while in other embodiments, the initiation and / or formation of the desired differentiated environment (which may include the formation of the complete differentiated environment, as well as the formation of various fouling inhibiting conditions that may be altered and / or supplemented as further aspects of the differentiated environment are induced) may require the enclosure to be in place around the substrate for at least 2 hours, at least 3 hours, at least 6 hours, at least 12 hours, at least 18 hours, at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days, at least 6 days, at least 1 week, at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 1 month, at least 2 months, at least 3 months, and / or at least 6 months or more.In various embodiments, the various water chemical composition differences that may occur during these various time periods may include dissolved oxygen, pH, total dissolved nitrogen, ammonium, ammoniacal nitrogen, nitrate, nitrite, orthophosphate, total dissolved phosphate, silica, salinity, temperature, turbidity, chlorophyll, etc.), the various concentrations of which may increase and / or decrease at different times, including different concentrations of individual components at different durations of enclosure flooding.

[0102] In some cases, the device of the present invention may degrade and no longer provide the desired level of anti-fouling and / or environment-shaping effect after a period of time. In various embodiments, the amount of time before the enclosure loses its anti-fouling effect may vary based on many factors, including the particular aquatic environment, season, temperature, the composition of marine life present, temperature, light, salinity, wind, water velocity. It should be noted that based on the conditions of the aquatic environment, the enclosure may temporarily lose its anti-fouling and / or environment-shaping effect, and only regain its anti-fouling / environment-shaping effect(s) when conditions return to normal or somewhat desired standards. As used herein, "service life" may refer to the amount of time from deployment of the enclosure until the level of macrofouling becomes a problem on the substrate, while "enclosure life" may refer to the amount of time the enclosure itself remains physically intact and effective around the substrate itself (which may be exceeded by the "service life" of the biofouling protection provided by the enclosure). In various embodiments of the invention, one or both of the enclosure service life and / or enclosure lifetime can be 3 days or more, 7 days or more, 15 days or more, 30 days or more, 60 days or more, 90 days or more, 120 days or more, 150 days or more, 180 days or more, 270 days or more, 1 year or more, 1.5 days or more, 2 years or more, 3 years or more, 4 years or more, or 5 years or more.

[0103] If desired, the enclosure or portions thereof may be constructed of degradable materials, which may optionally include biodegradable, photodegradable, oxidizable, and / or hydrolyzable materials, desirably resulting in a reduction in molecular weight, reduced mass, and / or reduced strength or durability (and other potential effects) of the enclosure or portions thereof over time under certain conditions. In various embodiments, continued exposure to an aquatic environment with such materials may eventually result in the delamination of the enclosure (or one or more layers thereof) from the substrate, and / or environmentally friendly degradation of the enclosure and / or its various components. Such delamination may include delamination of the entire enclosure and / or delamination of different layers in a manner that is released with time release and / or degree of fouling (i.e., weight-based, drag-based, and / or reduced wall flexibility).

[0104] Whatever the type of material used, the enclosure may optionally be constructed to be formable such that the structure can be expanded three-dimensionally, radially, longitudinally, and / or various combinations thereof. This type of construction desirably allows it to be positioned on the object in various configurations, which may include positioning, if desired, such that the enclosure walls may mirror the contours of the surface of the object to which they are attached. In some embodiments, the enclosure may be formed in a mirror image shape of one or more surfaces of the substrate, and will generally be at least slightly larger in size to accommodate the substrate therein.

[0105] In some exemplary embodiments, the enclosure may be constructed of entirely natural materials such as burlap or hemp and deployed to protect substrates in particularly sensitive waters such as drinking water reservoirs and / or wildlife refuges where the use of artificial materials and / or biocidal toxins may be prohibited and / or discouraged. In such cases, the enclosure will desirably provide protection to the underlying substrate for a desired period of time without posing a significant potential to contaminate the water and / or harm the local aquatic environment, even if the enclosure were to be peeled away from the substrate and / or associated support structure (as additional opening(s) in the peeled away structure would now prevent development of the protected aqueous environment and its attendant benefits). In such cases, once the substrate no longer requires protection or if the enclosure becomes contaminated and / or damaged for various reasons, the enclosure may be removed and / or replaced with a new enclosure and / or enclosure components of similar materials, and fouling prevention restored to the substrate as needed.

[0106] Enclosure Assembly In various embodiments, the enclosure may be constructed in a single piece or may include multiple modular pieces that may be assembled in a variety of enclosure shapes. For example, an enclosure design may desirably include multiple wall structures, each wall structure attached and / or assembled to one or more adjacent wall structures (if any) by stitching, weaving, hook-and-loop fasteners, Velcro, etc., which may include coating and / or encapsulation of any seams and / or stitched / glued areas. 6A and 6B illustrate an exemplary stitching technique that may be particularly well suited for use in constructing the various enclosures of the present invention, with the stitching thread 630 forming the seam 600 between a first fabric section 610 and an adjacent second fabric section 620 being positioned toward the differentiated (i.e., interior) environment such that the stitching thread and / or associated irregular surfaces of the seam or overlapping fabric folds are desirably not exposed to the exterior environment and thus desirably do not provide an exterior-facing surface that is open to biofouling of the enclosure (slight gaps formed along the exterior surface of the enclosure may not be optimal, but may be tolerable in various embodiments). Alternatively, other connection techniques such as thermal bonding, ultrasonic welding, and / or other energy-based bonding techniques, adhesives or glues, as well as other stitching and / or two-dimensional weaving / knitting techniques may be utilized as desired. In other alternative embodiments, three-dimensional fabric molding techniques may be used to create a "tube" or bag of material for the enclosure that has no exterior facing seams on the sides and / or only one or more seams and / or openings on the top and / or bottom. In some particularly desirable embodiments, the attachment and / or bonding of the various wall sections of the enclosure will preferably be accomplished such that some level of flexibility is maintained within the attachment areas.

[0107] In a similar manner, various embodiments of the enclosure will desirably incorporate permeable and / or flexible attachment mechanisms and / or enclosures such that relatively hard, uninterrupted, and / or impermeable surfaces are desirably not presented by the enclosure to the exterior of the surrounding aqueous environment. In many cases, biofouling entities may prefer a hard, uninterrupted surface for settlement and / or colonization that may provide such entities with a "foothold" for subsequent colonization on adjacent flexible fabric sections such as those of the enclosures described herein. By reducing the potential for such "foothold" locations, many of the disclosed enclosure designs may significantly improve the biofouling resistance of the various disclosed embodiments and / or their provided substrate protection. In at least one embodiment, the enclosure may be specialized for substrates that are fabricated as a single construction with no seams and / or impermeable wall sections.

[0108] In the case of hook-and-loop or "Velcro" fasteners, the employment of such connection devices may be particularly well suited to various enclosure embodiments in that such fasteners may be permeable to aqueous media in a manner similar to the permeable enclosure walls. Such design features may allow liquids within the enclosure to leach through the fastener components and / or enclosure walls in a similar manner, thereby inhibiting fouling of the fastener surface as described herein. Alternatively, the connection "flaps" of a flexible hook-and-loop fastener may be placed over a corresponding flexible or non-flexible attachment surface to provide additional protection to the attachment surface.

[0109] In various embodiments, the enclosure may desirably incorporate one or more features that reduce, mitigate, inhibit, and / or prevent the effects of hydrostatic pressure from damaging the enclosure, various enclosure components, protected substrates, and / or any connected objects and / or anchoring systems. For example, many of the enclosures may comprise flexible fabric materials (compared to non-flexible solid enclosures or enclosure walls) that may desirably reduce, reduce, and / or eliminate many of the effects of external water movement (i.e., currents, waves, and / or tidal action) on the enclosure and / or its components. In a similar manner, the presence of perforations and / or permeability of the enclosure walls desirably reduces and / or mitigates hydrostatic pressure acting on various portions of the enclosure and / or its supporting structure in that at least a portion of any hydrostatic pressure effects will desirably "pass" through the enclosure (typically resulting in a desired level of fluid exchange between the enclosure and the surrounding aqueous environment) and other portions of the enclosure will flex, bend, and / or "flap" in the moving water. Additionally, the employment of flexible compliant fabrics and / or other materials throughout most of the enclosure desirably reduces the potential for work hardening and / or fatigue failure of the various enclosure components, improving the durability and functional life of the enclosure. Thus, at least one exemplary embodiment of the enclosure may include one or more wall components (or the entire enclosure design) that may move and / or flex due to tides, currents, and / or wave motion in the vicinity of the enclosure.

[0110] In various embodiments, the permeability of the fabric may be influenced and / or altered by a variety of techniques, including mechanical processes, such as by the use of perforating devices (i.e., needles, laser cutting, stretching to create micropores, etc.), abrasive materials, and / or pressure and / or vacuum effects (i.e., water and / or air jets), or chemical means (i.e., etching chemicals). In a similar manner, low permeability fabrics are desirably treated to increase the permeability of the fabric to within a desired range, while in other embodiments, more permeable fabrics may be modified to a desired amount of lower permeability (e.g., by using paints, coatings, clogging, or coagulants).

[0111] In many embodiments, the type and / or permeability level of the enclosure wall material(s) selected will be a prominent consideration in the design and placement of the enclosure and / or various enclosure components. Upon initial placement of the enclosure in an aqueous medium, the permeable material will desirably allow sufficient water exchange to occur between the open environment and the enclosed and / or bounded environment to allow a differentiated environment to form that protects against biofouling. However, because various fouling pressures and / or other factors can potentially alter and / or otherwise affect the permeability and / or porosity of a given enclosure wall material over time in an aqueous medium, it is often important that the permeable material continue to allow the desired water exchange level that maintains the differentiated environment, and desirably avoids the occurrence of long-term anoxia within some enclosure embodiments. Due to these concerns, it may be desirable to select a higher permeability level for the enclosure wall material such that clogging and / or closure of some of the pores of the material should not significantly affect the anti-fouling performance of the enclosure, even though the water exchange rate may decrease, increase, and / or remain the same at different times during the enclosure's service life.

[0112] Alignment and Spacing In use, embodiments of the enclosure may desirably be applied around the substrate prior to submersion of the substrate in an aqueous medium. This includes protection of the object before it is first submerged in an aqueous medium (i.e., "virgin" submersion of the object in an aqueous environment), and protection of a previously submerged object that has been removed from an aqueous medium and cleaned and / or descaled, with the enclosure being applied to the object prior to subsequent submersion. In other embodiments, the enclosure may be applied to an object that has already been submerged in an aqueous environment, including an object that may have previously been submerged for an extended period of time and / or that already has a significant amount of biofouling thereon. Once the enclosure is applied to the object, it may be secured in several ways around one or more exposed surfaces of the substrate, thereby isolating the aqueous environment within the enclosure from the surrounding aqueous environment to various degrees partially and / or completely. It should also be understood that in various embodiments, the enclosure may not "completely" surround the substrate, such as when the enclosure may have relatively large gaps and / or openings therethrough. In such cases, the enclosure may still be sufficiently "closed" to effect desired environmental changes within the enclosure that reduce and / or prevent biofouling of the substrate and / or portions of the substrate, as described herein.

[0113] Non-limiting examples of substrates include, but are not limited to, sporting, commercial and military watercraft, boats, vessels and marine vessels, civilian boats, boats, vessels and marine vessels such as jet skis, propulsion systems for boats, vessels, vessels and marine vessels, drive systems for boats, vessels, vessels and marine vessels and their components such as stern drives, inboard drives, pod drives, jet drives, outboard drives, propellers, impellers, drive shafts, stern and bow thrusters, brackets, rudders, bearings, housings, etc. inlets for boats, ships, vessels, and offshore vessels, such as cooling water inlets, HVAC water inlets, and propulsion system inlets; marine work support equipment, such as docks, slips, pilings, piers, rafts, floating paint platforms, floating scaffolding platforms, and floating winch and towing equipment platforms; restraining and holding equipment, such as anchors, ropes, chains, metal cables, moorings, synthetic and natural fiber cables; pH measurements marine instrumentation, such as, for example, tachometers, dissolved oxygen meters, salinity meters, temperature meters, seismic meters, and motion sensor instruments and associated arrays; mooring equipment, such as, for example, anchor chains, anchor cables, attachment chains, attachment cables, mooring chains, mooring cables, fittings, floats, bollards, and associated attachments; buoys, wooden piles, metal piles, concrete dock piles, wharf piles, pier piles, channel marker piles, such as marker buoys, channel marker buoys, inlet marker buoys, diver buoys, and depth indicator buoys; , subsea structures such as marine pilings, such as subsurface structural pilings, seawalls, oil and gas rig exploration and production structures, municipal structures, commercial structures, and military structures, marine filtration systems, industrial filtration system equipment such as membrane filters, water inlet filters, piping and / or storage tanks, marine lift and boat storage structures, irrigation water storage tanks and irrigation piping and / or equipment, and / or any parts thereof, including water management systems and / or system components such as locks, dams, valves, gates and seawalls.Other mechanisms affected by biofouling that can be addressed using the present disclosure include microelectrochemical drug delivery devices, paper and pulp industry machinery, underwater equipment, fire protection system piping, and sprinkler system nozzles. In addition to obstructing mechanisms, biofouling also occurs on the surface of living marine organisms when they are known as epibenthic organisms. Biofouling is also found in almost any situation where water-based liquids are in contact with other materials. There are significant industrial impacts on marine cultures, membrane systems (e.g., membrane bioreactors and reverse osmosis spiral wound membranes), and cooling water cycles in large industrial equipment and power plants. Biofouling can also occur in oil pipelines that carry oils with entrained water, especially oil pipelines that carry used oils, cutting oils, oils that have become water-soluble through emulsification, and hydraulic oils.

[0114] In various embodiments, the substrate(s) to be protected can be a surface or subsurface made of any material, including, but not limited to, a metal surface, a fiberglass surface, a PVC surface, a plastic surface, a rubber surface, a wood surface, a concrete surface, a glass surface, a ceramic surface, a natural fiber surface, a synthetic fiber surface, and / or any combination thereof.

[0115] 7A illustrates one exemplary embodiment of a rolled sheet fabric 700 that incorporates adhesive, hook-and-loop material 710 (and / or stitching) along various portions of the fabric that may desirably self-adhere to other fabric portions, with the majority of the fabric including perforated or permeable portions 720 (and in various embodiments the fastener material itself may include permeable and / or non-permeable portions as well) as described herein. If desired, flaps of material covering some of the other fabric portions may be non-permeable to protect underlying structures.

[0116] In use, the fabric may be wrapped around a pile or support girder 730 (see FIG. 7B) to form an enclosure around several portions of the pile, which may include a progressive wrapping method 740 (i.e., a "barber pole" type wrapping) or a circular wrapping method 750 (i.e., a "round robin" type wrapping) to create various enclosures of similar functionality to those described herein to protect various portions of the pile from biofouling organisms and / or other degradation. In various embodiments, attachment using hook-and-loop or similar fasteners may be particularly desirable as such fastening techniques may be permeable, allowing water exchange therethrough in a manner similar to the various permeable materials described herein.

[0117] If desired, the enclosure may be constructed using individual component sections that may be assembled into a three-dimensional (3D) structure. For example, individual wall sections of the enclosure may be provided to be attached to one another in a variety of configurations, including triangles, squares, and / or other polygons. If desired, the wall sections may be supported by a relatively rigid frame, or the sections may be highly flexible and / or provided on rollers or other carriers and unfolded to release each individual section prior to assembly. In at least one alternative embodiment, an open enclosure frame or support may be provided, with elongated sheets or enclosure wall material provided that may be wrapped around and / or overlaid on the frame segments (and applied to the frame, e.g., in a manner similar to a "shipping wrap" of an object for shipping by a carrier).

[0118] Table 1 shows additional experimental results of microfouling experienced by various enclosure designs utilized in a seawater environment to protect various substrates, along with a control substrate (i.e., PVC pipe) in both a coated and uncoated condition (the coating containing a biocidal leaching component), the enclosure incorporating various fabrics wrapped around the PVC pipe. After 240 days of submersion in seawater, the various enclosures successfully protected the underlying PVC pipe substrate from fouling and were also highly successful in preventing biofouling entities from depositing on / within the fabric structure of the enclosure wall itself. These results were particularly striking when compared to the amount and type of biofouling accumulated on the uncoated control pipe, as well as the significant amount of fouling that deposited on a pair of control PVC pipes (WB Pnt pipe and SB Pnt pipe) that were directly applied / coated with a biocidal paint. [Table 1]

[0119] Visual analysis of the above enclosures and associated protected substrates after 240 days of submersion revealed that all of the intact enclosures protected the substrates to a highly desirable level. Specifically, the exterior surfaces of the substrates inside each of the enclosures were essentially free of fouling, with most substrate surfaces having, if any, a light coating of easily removable deposits and / or residues, and some horizontal surfaces on the substrates having developed deeper pockets of deposit buildup that were also easily removable. In addition, the enclosures protecting each of the substrates were only lightly fouled on their exterior surfaces, and each enclosure was still generally flexible despite the light coating of fouling. Importantly, all intact enclosures prevented macrofouling on the underlying PVC substrate. WB10 and WBDUK suffered some level of damage and / or decomposition to the enclosure walls that allowed some fouling to access the test section within the enclosure. The solvent-based biocidal coated enclosure was still in good condition, with some edge fraying and edge splitting after 240 days of submersion in salt water. After prolonged immersion, the water-based biocidal coated enclosure appeared to become progressively weaker, with noticeable edge splitting and some holes in the windings. In contrast, significant fouling occurred on both the solvent- and water-based coated pipes, but there was less fouling on the solvent-based coated pipes. The unprotected pipes were completely obscured under multiple layers of fouling in some areas, to a depth exceeding the diameter of the pipe.

[0120] In various instances in the above tests where the enclosures underwent unexpected openings, breaches, and / or became misaligned, the underlying substrates underwent very light fouling on their exterior surfaces in areas proximate to the unexpected opening(s) and / or breach(s), with many "exposed" areas of the substrates having little or no fouling coverage. In many cases, it was unclear when the failure of the various enclosures occurred, but most "failed" areas had the associated substrates exposed to the environment for at least a month or more. In these cases, it is believed that the initial placement of the enclosures caused and / or induced the formation of a "protective" biofilm layer on the surface of the substrate, which subsequently protected the substrates from significant additional fouling after the integrity of the enclosure was breached and the substrates were directly exposed to the outside environment.

[0121] water exchange rate In various embodiments, an optimal, desired, and / or average "water exchange rate" can be determined for protecting a given substrate in a given aqueous environment using a given enclosure design, which can include a range(s) of desired water exchange rate(s) that can vary due to a wide range of water and / or other environmental conditions. For example, the desired water exchange rate can be optimized to protect a particular type and / or shape of substrate material, can be designed and / or specified for a particular size, shape, and / or volume of enclosure and / or enclosure wall material, can be designed and / or specified for a particular area or water depth, can be dependent on seasonal variations and / or temperature and / or tidal activity, and / or can vary due to water salinity, dissolved oxygen, nutrients, waste, water velocity, the particular application, and / or numerous other considerations. In various embodiments, the water exchange rate will desirably be sufficient to create a desired gradient of conditions (i.e., dissolved oxygen, waste, available nutrients, etc.) between the external open environment and the internal environment within the enclosure to protect the underlying substrate surface from undesirable levels of biofouling without creating conditions that could unacceptably damage the substrate, e.g., to avoid the deleterious effects of anoxic conditions (i.e., in some embodiments, dissolved oxygen levels of approximately 0.5 mg / L or less) for extended periods of time that could lead to unacceptable levels of substrate corrosion.

[0122] In various embodiments, it would be highly desirable to allow the metered inflow of the "open" environmental waters to induce changes in the desired water chemistry (which may include desired concentrations of metabolic waste products and / or harmful, inhibitory and / or toxic by-products within the enclosure) within the enclosure and in the metered outflow of the enclosure water, such that various harmful compounds, including various known and / or unknown microbial "toxins" and / or inhibitory compounds, and / or other water chemistry factors may elute through the enclosure walls and protect the enclosure's exterior surface and / or pores from excessive fouling (in some embodiments, the water flow conditions may create a "swarm" of such compounds that substantially surrounds some or all of the enclosure's exterior walls). In these embodiments, the presence of the enclosure may provide differing degrees of biofouling protection to both the substrate and the enclosure walls, even in the absence of supplemental biocides or other fouling protection toxins supplementally provided to the enclosure. For example, when various enclosure embodiments are placed around a substrate to form the disclosed differentiated environment, the differentiated environment may also develop elevated concentrations of various metabolic waste products, and various processes and / or metabolic activities occurring within the enclosure may generate one or more substances (e.g., hydrogen sulfide or NH3-N, etc.) that are harmful and / or have adverse effects on fouling organisms. These harmful compounds may then increase in concentration and reside and / or elute on the walls of the enclosure, creating a localized "swarm" of harmful compounds that to some extent protects the exterior walls of the enclosure from fouling organisms. However, once the harmful compounds leave the enclosure, they become quickly diluted and / or decomposed by various natural processes, many of which utilize the abundant dissolved oxygen outside the enclosure, thus eliminating any concerns regarding the longer term effects of these substances. Additionally, because the processes that create these harmful compounds within the enclosure are continuous and / or cyclical, the enclosure may potentially generate a new supply of these compounds at a relatively constant level indefinitely.

[0123] In various embodiments, a desired water exchange rate of at least 0.5% or more of the total water volume within the protective enclosure exchanged between the protective enclosure and the surrounding aqueous environment per minute may provide a wide variety of anti-fouling and / or anti-corrosion effects on the protected substrate as described herein, while exchange rates of less than, equal to, and / or greater than 0.5% per minute may desirably provide various anti-fouling and / or anti-corrosion benefits as described herein. This exchange rate may optionally be determined as an average rate over a particular period of time, such as per minute, per hour, per day, and / or per week, and during periods of moving and / or non-moving water, such as during slack water and / or tides. In other embodiments, a desired water exchange rate of up to 5% of the total water volume within the enclosure per minute exchanged between the protective enclosure and the surrounding aqueous environment may provide a wide variety of anti-fouling and / or anti-corrosion effects on the protected substrate as described herein, while exchange rates of less than, equal to, and / or greater than 5% per minute may desirably provide various anti-fouling and / or anti-corrosion benefits as described herein.

[0124] In one exemplary embodiment, an enclosure that allows for a water exchange rate of approximately 0.417% of the enclosed or bounded water volume per minute (i.e., approximately about 25% of the total enclosed or bounded volume per hour) has been shown to provide a substrate with better biofouling resistance. The enclosed or bounded water volume within an exemplary enclosure may be calculated as the enclosed or bounded total volume of the enclosure minus the volume of the substrate within the enclosure. In other embodiments, the water exchange rate may be approximately 25% of the enclosed or bounded total volume of the enclosure per hour, without taking into account the volume of the substrate within the enclosure.

[0125] In various embodiments, a water exchange rate of less than 0.1% per minute may provide the desired level of anti-fouling and / or corrosion protection, while in other embodiments a desired water exchange rate within 0.1%-1% of the total water volume per minute may be effective, in other embodiments a water exchange rate of 1%-5% of the total water volume may provide the desired level of anti-fouling and / or corrosion protection, while in other embodiments a desired water exchange rate of 5%-10% of the total water volume per minute may be effective. In other embodiments, the desired exchange rate may range from 1% to 99% of the total water volume per minute, 5% to 95% of the total water volume per minute, 10% to 90% of the total water volume per minute, 15% to 85% of the total water volume per minute, 25% to 75% of the total water volume per minute, 30% to 70% of the total water volume per minute, 40% to 60% of the total water volume per minute, or approximately 50% of the total water volume per minute. In other embodiments, the water exchange rate may vary from 10% to 50% or 10% to 15%, 15% to 25%, and / or 25% to 50% per minute, or various combinations thereof (i.e., 1% to 10% per minute or 5% to 25% per minute, etc.). In various embodiments, such water exchange rates may be obtained within an enclosure using various permeable fabrics disclosed in FIG. 19 and Table 3 (below).

[0126] It will also be appreciated that where local water conditions provide for higher water flow rates on and / or off the enclosure, and / or where the enclosure may be moved (i.e., by being moved and / or attached to a moveable object), a lower permeability of the enclosure material will be more desirable in that the higher velocity of water contacting and / or impinging on the enclosure wall(s) will cause a sufficiently large amount of liquid to permeate through the permeable fabric than would normally occur in a fibrous substrate and / or a relatively still body of water, thereby causing the water exchange rates desired to provide biofouling protection as described herein. In a similar manner, when local water conditions provide for slower water flow over and / or away from the enclosure, a higher permeability of the enclosure material is more desirable in that the slower water velocity contacting and / or impinging on the enclosure wall(s) will allow a sufficiently smaller amount of liquid to permeate through the permeable fabric than would normally occur in a fibrous substrate and / or relatively active body of water, thereby causing the water exchange rates desired to provide biofouling protection as described herein. [Table 2]

[0127] In various embodiments, it may be desirable to employ an enclosure design that contains a sufficient amount and / or volume of "aqueous medium" to allow the described differentiation of the enclosed environment to occur, while also containing a sufficient "reservoir" of fluid to allow for the "accumulation" of sufficient concentrations of toxic and / or harmful chemicals and / or compounds to maintain the desired concentrations of such chemicals / compounds during the desired water exchange period. In some cases, the enclosed volume of aqueous medium (i.e., water) within the enclosure may be several times the volume of the enclosed substrate, particularly for relatively small substrates such as sensors and / or water intakes, while in some other embodiments, the enclosed volume of aqueous medium within the enclosure may be a fraction of and / or equal to the volume of the enclosed substrate (i.e., in some cases for ship hulls and / or other large structures). In various embodiments, the surface-to-volume ratio may be utilized to describe various enclosure designs, which may include three exemplary enclosure embodiments having surface-to-volume ratios ranging from 0.4 to 800 inverse feet, as shown in Table 2, such as a pumping cube enclosure design having a surface-to-volume ratio of 0.4 inverse feet or less, a boat hull enclosure design having a surface-to-volume ratio of 800 inverse feet or more (for vessels 50 feet or greater), and a stern mimicking enclosure design having a surface-to-volume ratio of 350 inverse feet (less than or equal to).

[0128] In other embodiments, the enclosure may be designed with a particular surface area ratio and / or range of surface area ratios compared to the surface area of ​​the enclosed substrate, which may vary widely depending on the enclosure design and / or surface enclosure design and / or surface texture, and / or fully or partially submerged and / or other features of the substrate. For example, a given enclosure design and / or size may be utilized to protect a generally smooth surface of the substrate as well as a more complex substrate surface (i.e., a valve and / or a propeller), with a surface area ratio of approximately 1:1 or 1.1:1 for enclosure / smooth substrate, or approximately 1:2 or greater for enclosure / complex substrate. In a similar manner, a complex enclosure design may have a ratio of 1.1:1 or greater for a less complex substrate. In various embodiments, the enclosure will have a surface area ratio in the range of 1:1.1 to 1.1:1 for a given protected substrate, and this range can extend to 1:2 to 2:1 or more in both directions for various degrees of substrate and / or enclosure complexity. In general, the enclosure design is expected to be at least slightly larger than the substrate (for some amount of water in the enclosure) and the surface features of the enclosure are expected to be somewhat less complex than those of the substrate, so that in many embodiments the surface area ratio of the enclosure to the substrate will be approximately 1:1, or 2:1, or 3:1, or 10:1, or 50:1, or 100:1, or more. In other embodiments, the surface area of ​​the enclosure design is expected to be less than the surface area of ​​the substrate. This can occur when the substrate is partially submerged in the unit, whether it is 1%, 5%, 10%, 20%, 25%, 50%, 60%, 75%, 80%, 95%, 99% or less of the substrate being submerged. In some embodiments, the surface area ratio of the enclosure to the substrate will be approximately 1:1, or 1:2, or 1:3, or 1:10, or 1:50, or 1:100, or lower.

[0129] transparency One important aspect of the various enclosure embodiments disclosed herein is the incorporation of permeable elements, components, and / or structures into some and / or all of the enclosure components, which allow some bulk transport of water into and / or out of the enclosure in a controlled manner and / or rate. Desirably, the material(s) selected for the enclosure will include one or more walled structures that have a level of permeability that allows some level of "bulk fluid exchange" between the enclosure and the surrounding aqueous environment. This permeability will desirably be optimized and / or suitable for the local environment in which the enclosure will be placed, but generally the enclosure may incorporate a low to moderate level of permeability since an enclosure material with very high permeability may be somewhat less effective at altering the chemical composition of the water within the enclosure and / or limiting or reducing biofouling on the protected article, whereas an enclosure material with very low or no permeability (or which may become very low permeable over time for a number of reasons, including due to fouling on and / or in the fiber surfaces) may lead to unacceptably low levels of liquid exchange through the fabric walls, which may lead to various substrate corrosion or other problems resulting from low oxygen levels (i.e., anoxic or other conditions) or other chemical levels within the protected environment. In various locations and / or environmental conditions (including various changes in seasons and / or weather patterns), increased or decreased permeability or other enclosure design changes may be desired. In many cases, local environmental conditions (i.e., water flow, temperature, bio-floral type, growing season, salinity, available nutrients and / or oxygen, contaminants, etc.) and / or local water conditions / velocities (i.e., due to currents and / or tides) may affect the desired permeability and / or other design considerations; for example, higher velocity liquid impingement on the enclosure may result in increased water exchange rates for a given permeability of the material, which may require or suggest the use of a less permeable material in such conditions.

[0130] In various embodiments, the enclosure may desirably inhibit biofouling of a substrate or substrate portion at least partially immersed in an aquatic environment, the enclosure comprises a material that is or becomes water permeable during use, the enclosure is adapted to receive the substrate and form a distinct aquatic environment extending from the surface of the substrate to at least the interior / exterior surface of the structure, and the structure or portion thereof has a water permeability of about 100 milliliters / second of water per square centimeter of substrate or less during or after positioning the structure about the substrate. In various embodiments, the water permeability of the structure may be achieved by forming a structure that allows water to pass therethrough, such as by manufacturing a fiber to have a desired permeability. In some embodiments, the structure may be designed to become water permeable over time as it is used. For example, an otherwise water-permeable structure may initially include a coating that renders it substantially impermeable (which may be particularly useful for "jump-starting" desired hypoxic conditions within the enclosure immediately after initial placement), but as the coating dissolves, erodes, or dissolves, the underlying permeability increases and / or becomes useful (which may help prevent oxygenated water from permeating into the enclosure and creating undesirable sustained anoxic conditions within the enclosure after hypoxic conditions have been reached).

[0131] In various embodiments, the optimum and / or desired permeability level for the enclosure fabric may approximate any of the fabric permeabilities identified in Table 3 (below), and in some embodiments, 100 ml / sec / cm 2 ~0.01ml / sec / sm 2 In various alternative embodiments, the fabric or other permeable material may have a permeability in the range of 0.06 ml / sec / cm 2 ~46.71ml / sec / cm 2 , or 0.07 ml / sec / cm 2 ~46.22ml / sec / cm 2 , or 0.08 ml / sec / cm 2 ~43.08ml / sec / cm 2 , or 0.11 ml / sec / cm 2~42.54ml / sec / cm 2 , or 0.13 ml / sec / cm 2 ~42.04ml / sec / cm 2 , or 0.18 ml / sec / cm 2 ~40.55ml / sec / cm 2 , or 0.19 ml / sec / cm 2 ~29.08ml / sec / cm 2 , or 0.32 ml / sec / cm 2 ~28.16ml / sec / cm 2 , or 0.48 ml / sec / cm 2 ~25.41ml / sec / cm 2 , or 0.50 ml / sec / cm 2 ~22.30ml / sec / cm 2 , or 0.77 ml / sec / cm 2 ~21.97ml / sec / cm 2 , or 0.79 ml / sec / cm 2 ~20.46ml / sec / cm 2 , or 0.83 ml / sec / cm 2 ~15.79ml / sec / cm 2 , or 0.90 ml / sec / cm 2 ~14.72ml / sec / cm 2 , or 1.05 ml / sec / cm 2 ~14.19ml / sec / cm 2 , or 1.08 ml / sec / cm 2 ~14.04ml / sec / cm 2 , or 1.11 ml / sec / cm 2 ~13.91ml / sec / cm 2 , or 1.65 ml / sec / cm 2 ~11.27ml / sec / cm 2 , or 2.09 ml / sec / cm 2 ~11.10ml / sec / cm 2 , or 2.25 ml / sec / cm 2 ~10.17ml / sec / cm 2 , or 2.29 ml / sec / cm 2 ~9.43ml / sec / cm 2 , or 2.36 ml / sec / cm 2 ~9.20ml / sec / cm 2, or 2.43 ml / sec / cm 2 ~9.02ml / sec / cm 2 , or 2.47 ml / sec / cm 2 ~8.24ml / sec / cm 2 , or 2.57 ml / sec / cm 2 ~8.16ml / sec / cm 2 , or 2.77 ml / sec / cm 2 ~8.11ml / sec / cm 2 , or 3.68 ml / sec / cm 2 ~6.04ml / sec / cm 2 , or 3.84 ml / sec / cm 2 ~5.99ml / sec / cm 2 , or 4.43 ml / sec / cm 2 ~5.40ml / sec / cm 2 , and / or 4.70 ml / sec / cm 2 ~4.77ml / sec / cm 2 The present invention may be utilized in or on one or more walls of the enclosure, including a material having a permeability of .

[0132] In various embodiments, the optimal and / or desired water exchange rate between the distinct environment within the enclosure and the open environment is between about 0.1% to about 500%, about 0.1% to about 400%, about 0.1% to about 350%, about 20% to about 375%, about 0.1% to about 100%, about 0.1% to about 250%, about 20% to about 500%, about 50% to about 200%, about 100% to about 200%, about 0.1% to about 2 ... The hourly rate may be in the range of about 00% to about 200%, about 25% to about 200%, about 25% to about 100%, about 10% to about 75%, about 25% to about 275%, about 100% to about 500%, about 100% to about 250%, about 50% to about 150%, about 75% to about 200%, about 20% to about 350%, about 50% to about 100%, about 0.2% to about 120% per hour, about 0.2% to about 20% per hour, about 20% to about 50% per hour, or approximately 25% per hour.

[0133] When an enclosure is utilized to protect a substrate as disclosed herein, the biological colonization sequence on the substrate will be significantly different from the normally expected open water sequence. For example, when an enclosure as described herein is utilized, the biological colonization sequence on the substrate can be disrupted (disrupted, altered, etc.) to reduce and / or minimize the settlement, recruitment, and eventual macrofouling of the substrate. Once positioned around or within the substrate (when protecting the substrate's interior surface), the permeable protective fabric wall of the enclosure can desirably filter and / or impede the passage of various micro- and / or macro-organisms into the enclosure, and the different water conditions created between the enclosure wall and the substrate can prevent some and / or all of the organisms from settling and / or colonizing the substrate when the organisms are already located within the enclosure and / or when the organisms eventually pass through the enclosure. For example, as microscopic plankton and other traditionally non-settling and other sedentary organisms pass through the permeable fabric membrane of the enclosure, the various water conditions within the enclosure may harm or injure some of the plankton, while other plankton that survive and remain active will avoid settling and / or colonizing the substrate surface.

[0134] In various embodiments, an apparatus may be prepared in which the permeability of candidate materials may be evaluated in a laboratory, such as a water column pressure test apparatus commonly known to those skilled in the art. For example, an exemplary test apparatus may utilize a pump to supply water from a reservoir to a water column of a particular height, with the test sample being inserted at the bottom of the column. Optionally, if desired, an overflow may be integrated into the design so that the height of the water in the column is desirably kept constant. The test sample size may be varied as needed. In one test setup, the water in the column above a 4" x 4" fabric coupon may be kept constant at a height of approximately 3 inches, providing a "head" pressure of 0.25 PSI. The permeability of each fabric coupon may then be calculated by measuring the volume per unit area per unit time exposed to the water column. If desired, the material may be tested in a pre-wet condition, while in other tests, the material may be dried prior to the start of testing. In at least one exemplary embodiment, it was observed that using dried samples for permeability testing did not allow the water to flow evenly through the test apparatus, preventing accurate measurements. [Table 3]

[0135] Tables 4A and 4B show experimental permeability results for various fabrics and coated fabrics, both at pre-immersion conditions and after 23 days of immersion in an aqueous environment (i.e., seawater). From Table 5B, it can be seen that the permeability of the burlap test samples was significantly lower than that of the spun polyester. However, both burlap and spun polyester performed somewhat similarly to anti-foulant fabrics, at least in part, by excluding larger larval macroorganisms from the substrate environment. In various cases, the permeability of the fabric may decrease as a function of time associated with surface fouling and / or other fabric degradation. One notable result of this test is that due to the decomposition and / or other characteristics of burlap, as well as production challenges that may exist with various natural fibers, such as pest control, cleaning, sterilization, and / or contamination of production equipment (i.e., natural fibers may require more extensive and frequent equipment cleaning during the process than synthetic materials), spun polyester may be a preferred material over burlap (which may be less preferred, but still acceptable in various applications). [Table 4] [Table 5]

[0136] The water permeability of a material may be a function of a number of factors, including the composition of the material, the method and type of construction of the material, whether the material is coated or uncoated, whether the material is dry, wet, or saturated, whether the material itself is contaminated in any way, and / or whether the fabric is "pre-moistened" prior to testing and / or use in an aqueous environment. Furthermore, the permeability of a given material may change over time, so that even for a single material, there may be a range of acceptable and / or optimal water permeabilities. In various aspects of the invention, the water permeability of the enclosure may desirably be an initial minimum permeability sufficient to avoid the formation of constant anoxic conditions in the local (i.e., protected within the enclosure) aquatic environment, while in other embodiments the permeability may be greater. In various aspects of the invention, the encapsulant material has a viscosity of about 100 or less, about 90 or less, about 80 or less, about 70 or less, about 60 or less, about 50 or less, about 40 or less, about 30 or less, about 25 or less, about 20 or less, about 10 or less, about 5 or less, about 4 or less, about 3 or less, about 2 or less, about 1 or less, about 0.5 or less, about 0.1 or less, about 1 or more, about 0.5 or more, about 0.1 or more, about 0.1 to about 100, about 0.1 to about 90, about 0.1 to about 80, about 0.1 to about 70, about 0.1 to about 60, about 0.1 to about 50, about 0.1 to about 40, about 0.1 to about 30, about 0. The water permeability (milliliters of water per second per square centimeter of substrate) is from 1 to about 25, from about 0.1 to about 20, from about 0.1 to about 10, from about 0.1 to about 5, from about 0.5 to about 100, from about 0.5 to about 90, from about 0.5 to about 80, from about 0.5 to about 70, from about 0.5 to about 60, from about 0.5 to about 50, from about 0.5 to about 40, from about 0.5 to about 30, from about 0.5 to about 25, from about 0.5 to about 20, from about 0.5 to about 10, from about 0.5 to about 5, from about 1 to about 100, from about 1 to about 90, from about 1 to about 80, from about 1 to about 70, from about 1 to about 60, from about 1 to about 50, from about 1 to about 40, from about 1 to about 30, from about 1 to about 25, from about 1 to about 20, from about 1 to about 10, or from about 1 to about 5.

[0137] Dissolved oxygen In various embodiments, the placement of the enclosure in the aqueous medium around the substrate desirably "conditions" the dissolved oxygen and creates a dissolved oxygen differential between the water bodies inside and outside the enclosure, which desirably provides a significant improvement in preventing fouling of the protected article. In many cases, the dissolved oxygen conditioning of the differentiated environment may involve the creation of a significantly lower dissolved oxygen level within the enclosure compared to the external environment, which may fluctuate to various degrees in response to internal oxygen consumption and external dissolved oxygen levels. In addition, a secondary gradient may also exist between the dissolved oxygen of the "bulk water" within the differentiated environment and the dissolved oxygen in the water within the "boundary layer" at the surface of the protected substrate or article, which is at least partially due to the low energy environment within the enclosure compared to the external environment and / or the absence of significant turbulent and / or eddy currents that may "mix" the water within the enclosure. These localized differential conditions may be caused by consumption of oxygen and / or nutrients by organisms and / or other factors in the water column at the substrate or on the surface of the article and / or within the enclosure, which may lead to a more depleted "boundary layer" that contributes to a lack of biofouling and / or the formation of an anti-biofouling biofilm on the protected article.

[0138] Generally, 100% DO ("dissolved oxygen") means that the water contains as many dissolved oxygen molecules as possible at equilibrium, while DO above 100% means that the water is "supersaturated" with oxygen (this can often occur in seawater due to the effects of photosynthesis, atmospheric exchange, and / or temperature changes). At equilibrium, the percentage of each gas in the water can approximate, but is rarely the same as, the percentage of each gas in the atmosphere. Thus, at equilibrium, the percentage of oxygen in the water (relative to other gases in the water) can be comparable to the percentage of oxygen in the atmosphere (relative to other gases in the atmosphere). However, the specific concentration of dissolved oxygen in a body of water will typically vary based on other factors such as temperature, pressure, salinity, and the availability of photosynthesis and / or surface agitation. First, the solubility of oxygen decreases as temperature increases. Thus, hotter water contains less dissolved oxygen at 100% saturation than cooler water, and therefore cooler water can carry more oxygen. For example, at sea level and 4°C, 100% air saturated water will hold 10.92 mg / L of dissolved oxygen. However, when the temperature is increased to room temperature of 21°C, 100% air saturation will only hold 8.68 mg / L of DO. Second, dissolved oxygen increases with increasing pressure. Deeper water can hold more dissolved oxygen than shallower water. Due to hydrostatic pressure, gas saturation decreases by 10% with each meter of depth. Thus, if the concentration of dissolved oxygen is at 100% air saturation at the surface, 3 meters below the surface, there will be only 70% air saturation, even though there is still the same amount of oxygen available for biological demand. Third, dissolved oxygen decreases exponentially with increasing salinity. Thus, at the same pressure and temperature, salt water holds about 20% less dissolved oxygen than fresh water. Additionally, the dissolved oxygen at any particular time may not be in equilibrium with the environment because the factors mentioned above change (e.g., air or water temperature may vary throughout the day) and equilibrium may not yet be achieved.Additionally, wind and other water agitation can lead to aeration of the water beyond that expected under ambient conditions, and local oxygen use and / or production by biological and / or other processes can continually increase or decrease the amount of dissolved oxygen.

[0139] In various embodiments, once the enclosure described herein is placed around the substrate in an aqueous environment, the dissolved oxygen within the enclosure will desirably be utilized by various naturally occurring biological and / or other processes, which will cause the localized dissolved oxygen level within the enclosure to begin to change relative to the dissolved oxygen level in the water outside the enclosure. Because osmotic transport of dissolved oxygen occurs very slowly in water, and because there is typically little or no sunlight energy entering the enclosure to allow oxygen production via photosynthesis, the primary source of additional dissolved oxygen into the enclosure generally comes from the bulk transport of water outside the enclosure (which typically carries a higher percentage of dissolved oxygen) through openings in the enclosure walls and other components. This additional dissolved oxygen is then utilized within the enclosure in a manner similar to that described above, and the cycle continues to repeat until the dissolved oxygen level within the enclosure, typically a stable level, is reached that is generally above the anoxic level, but significantly lower than the oxygen level outside the enclosure.

[0140] Exemplary Dissolved Oxygen Measurement Protocol In determining the dissolved oxygen content of a given area, and the difference between two aqueous areas, dissolved oxygen (DO) sensing probes may be utilized. For continuous monitoring, individual probes may be preferred over bundled sensor packages, primarily due in part to the manner in which DO values ​​are determined from collected measurements.

[0141] For various measurements, the DO sensor will collect a reading(s), which can then be processed against readings from other sensor types to output a usable value. DO concentrations such as mg / L may then require a reference to a salinity / temperature data file. DO percent saturation measurements may require an atmospheric pressure data file in addition to the salinity / temperature file. All sensors may be calibrated within acceptable tolerances, and the chances that any two sensors will hold the same calibration are extremely low. This variability in calibration is one reason why individual probes are more likely to give better results than bundled sensors.

[0142] When groups of sensor readings are all processed with the same temperature, salinity, and pressure files, the DO data produced is directly comparable. Conversely, each sensor bundle typically processes its raw data internally. The inherent variability of each probe in such cases may be compounded when the data is calculated. This may lead to a greater margin of error when comparing sensor bundles than when comparing individual DO probes. To further support reliability, the calibrations of all DO probes should be compared.

[0143] New probes and recently repaired probes (such as replacement of sensor face) should be calibrated according to manufacturer specifications. All of the DO probes should be placed in a bucket or other container of water so that readings can be compared (along with the temperature / salinity gauges). The water should be bubbled or pumped to maintain an even flow, and the probes should be evenly distributed. The pressure sensors should be in close proximity. Once processed, data collected in this manner is likely to show any significant variability between probes. This comparison should be done at the beginning and end of the sensor deployment.

[0144] In one exemplary method, utilizing a HOBO brand water quality monitoring probe, the method of use may be to (1) install the sensor cap and perform both 100% and 0% calibration for all U26-001 DO loggers according to the manufacturer's specifications. (start-up details may be set at this point if desired); (2) determine appropriate logging intervals; (3) for deployments longer than one day, sample every 0.5 hours; for shorter deployments, more frequent sampling may be desirable; (4) to synchronize data, all loggers should be set to sample at the same intervals and should be set to start at the same time and data, utilizing the delayed start feature; (5) consider performing a "bucket comparison" when setting start times; (6) start up pressure sensors (U20L water level logger), temperature / salinity sensors (U24-002-C conductivity logger) and all DO sensors (U26-001 dissolved oxygen logger) according to manufacturer's specifications; (7) prepare all sensors and test fixtures for deployment; (8) offload sensor data immediately prior to deployment to eliminate irrelevant data; (9) deploy all sensors; (10) test all sensors deployed for open water readings (and Recall that sensors that are not adequately protected from macrofouling (and sensors not adequately protected from macrofouling) will need to be maintained to avoid data drift associated with macrofouling (depending on location and season, this can be as frequent as every other day, but typically in tropical and subtropical regions every few days is sufficient; the goal is to gently wipe the slime layer off the logger, especially the sensor face, before macrofouling can form; removing macrofouling from the sensor face can damage the coating on the optical sensor; if possible, alternating between taking the two sensors in and out of the water on a twice-weekly schedule, gently wiping before each redeployment, is very effective; these two data sets must then be combined to create one continuous open water data set; when the logger is swapped out, the data is offloaded to a waterproof shuttle.This will give one "underwater" and one "out of the water" data set from each swap out, which can simply be combined to create the desired data set; select the two loggers with the closest calibration results from the "bucket test" for the open water data); (11) offload sensor data at appropriate intervals; for long term deployments, monthly data acquisition is sufficient; (12) process the data using the dissolved oxygen assistant in HOBOware Pro or other suitable software; when combining large data sets in excel, the comma separated data import assistant is very efficient; (13) when an experiment has run its course or a logger can be introduced for sensor face replacement (every 6 months per manufacturer's specifications), do a "bucket compare" for calibration reliability and store the results for future reference.

[0145] Bucket Comparison If desired, a comparison of the sensors can be performed, which can be used to verify the reliability of the calibration and store the results for future reference. Some of the steps in such a comparison include (1) placing the DO logger and conductivity logger in a 5 gallon plastic bucket 1 / 2 filled with water at least 15 minutes before the first sampling interval, (2) holding the pressure sensor near the bucket for the duration of the test, (3) distributing the sensors evenly within the bucket, (4) placing an air stone in the center and middle of the water column to generate water movement for the duration of the test, (5) allowing the test to run for at least 24 hours, (6) offloading the data from the loggers using a waterproof shuttle (U-DTW-1) or similar device following manufacturer's specifications, and (7) processing the data using the Dissolved Oxygen Assistant in HOBOware Pro or equivalent software, i.e., opening the DO dataset with HOBOware pro, selecting process data with the Dissolved Oxygen Assistant, specifying the conductivity file to use, specifying the pressure file to use, and once the dataset is generated, exporting it to an excel file for processing and comparison, completing the process for all DO loggers, combining the data from the excel file and comparing the calibrations).

[0146] 8A and 8B graphically illustrate exemplary dissolved oxygen levels within the various test enclosures compared to the dissolved oxygen levels of the surrounding aqueous environment (i.e., the "open" readings). In these embodiments, the dissolved oxygen levels were consistently lower within the enclosures than the open readings of each of the enclosures, thereby creating a "different environment" from the surrounding aqueous environment. However, because the various enclosures were capable of various levels of "fluid exchange" with the external aqueous environment, many other characteristics of the overall water quality within the enclosures (including pH, temperature, and salinity) were the same or similar to the characteristics of the surrounding aqueous environment (see FIGS. 9 and 13).

[0147] Over a 24-hour period, the oxygen level outside the enclosure will typically fluctuate in a diurnal manner as shown in FIG. 10A, with high levels of dissolved oxygen occurring during the day (light areas of the graph) due to photosynthesis, and dissolved oxygen levels dropping during periods of darkness (shaded areas of the graph). Within the enclosure, the dissolved oxygen level over the same 24-hour period will typically fluctuate in a similar manner to the level outside the enclosure, as the amount of "dissolved oxygen replacement" entering the enclosure via bulk fluid transport will vary depending on the dissolved oxygen level outside. Additionally, because the replacement dissolved oxygen enters the enclosure in close proximity to the enclosure walls, there is often limited bulk movement and / or mixing of water within the enclosure, causing a gradient of high to low dissolved oxygen to typically exist between the enclosure walls and the surface of the protected substrate.

[0148] As seen in Figures 10A and 10B, the enclosures described herein may desirably control, mitigate, and / or "smooth" the dissolved oxygen levels in the differentiated aqueous environment (i.e., adjacent to the protected substrate) as compared to the DO level of the water in the surrounding open aqueous environment. In many instances, the DO level within the enclosure will desirably be lower than the DO level of the surrounding aqueous environment (see Figures 8A, 8B, 10A, and 10B), but the differentiated DO level may periodically exceed the DO level of the surrounding open aqueous environment in some embodiments and / or under some conditions. In addition, the enclosures described herein desirably maintain differentiated DO levels above anoxic DO levels, but periodic and / or intermittent differentiated DO levels that fall within the anoxic range may be acceptable in a variety of situations, including situations where the anoxic periods are short enough to allow little or no anoxic corrosion of the substrate to occur.

[0149] In various embodiments, dissolved oxygen levels of 0.5 mg / L or less may be considered undesirable and / or "anoxic" conditions, while dissolved oxygen levels of about 2 mg / L (or less) can cause significant adverse effects on the ability of aquatic organisms to colonize, thrive, and / or reproduce in an aqueous environment.

[0150] In many cases, a significant change in the dissolved oxygen content of a given aqueous environment can trigger a rapid response from many organisms, and a downward change in DO levels is one of the parameters to which organisms respond most quickly. The classification of bacteria or other organisms as anaerobic, aerobic, or facultative is typically based on the type of reaction they employ to generate energy for growth and other activities. In their metabolism of energy-containing compounds, aerobes require molecular oxygen as a terminal electron acceptor and typically cannot grow without it. Anaerobes, on the other hand, typically cannot grow in the presence of oxygen, which is toxic to them, and therefore anaerobes must rely on other substances as electron acceptors. The metabolism of anaerobes is often of the fermentation type, where anaerobes reduce available organic compounds to a variety of end products, such as organic acids and alcohols. Facultative organisms are the most versatile. Facultative organisms preferentially utilize oxygen as a terminal electron acceptor, but can also metabolize in the absence of oxygen by reducing other compounds. For example, when a molecule of glucose is completely decomposed into carbon dioxide and water in the presence of oxygen in the form of high-energy phosphate (38 molecules of ATP), much more usable energy is obtained than when it is only partially decomposed by fermentation processes in the absence of oxygen (2 molecules of ATP). In some cases, the reduction in DO levels within the enclosure may prompt the organism to change the rate and / or type of its metabolic pathways, which may include adapting to the new DO levels, while other organisms may simply enter a quiescent state and / or die. If the enclosure environment has an undesirably low level of DO, the organism will generally seek another environment with a higher DO level to colonize (and / or attempt to leave the lower DO environment), since remaining in the enclosure's lower DO environment may be negative, as it may adversely affect colonization ability and / or cause various health problems and / or death if the organism does not find an increased DO environment.

[0151] In various embodiments, the optimal and / or desired level of DO within the enclosure can be an average of at least 20% or more, an average of at least 50% or more, an average of at least 70% or more, an average of 20% to 100% DO content, an average of 33% to 67% DO content, an average of 50% to 90% DO content, or an average of 70% to 80% DO content. Alternatively, the desired DO level within the enclosure can be an average of at least 10% less DO content than the dissolved oxygen level in the water detected at some distance from the exterior of the enclosure (i.e., 1, or 2, or 5, or 10, or 12 inches, or 2, or 5, or 10 feet away from the enclosure).

[0152] In various embodiments, the modulation of dissolved oxygen within the enclosure will induce a dissolved oxygen differential of at least 10% between the differentiated environment within the enclosure and the open aqueous environment outside the enclosure. In various embodiments, this difference may occur within / after a few hours after the enclosure is placed in the aqueous medium, or may occur within 2-3 hours, 6 hours, 12 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, or even 1 month after the enclosure is placed. In various alternative embodiments, a desired dissolved oxygen differential of at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 50%, at least 70%, and / or at least 90% or more will be produced.

[0153] In many cases, dissolved oxygen levels within a given enclosure will become depleted by biological and / or other processes, and maintenance of dissolved oxygen levels within various enclosure designs potentially depends on the influx of dissolved oxygen (such DO levels being higher than DO levels within the enclosure) from the surrounding aqueous environment through the enclosure walls, which may also occur at some level via diffusion through the wall structure itself, entrainment of bulk transfer of water through permeable enclosure walls. The structures and methods described herein desirably provide enclosures with adequate levels of "water exchange" to provide sufficient water flow (and / or dissolved oxygen flow) within and / or through the structure to avoid the formation of anoxic environments within the enclosure for extended periods of time that may lead to corrosion of metal surfaces, but also desirably form localized aquatic environments and / or biofilm coatings on the substrate that minimize and / or prevent aquatic organisms from settling and / or thriving on the substrate. In particular, the devices of the present invention will desirably provide a level of permeability intended to maintain a dissolved oxygen (DO) level in a distinct aquatic environment (i.e., surrounding the object being protected) at a level that is "different" from the DO level(s) of the surrounding aqueous environment.

[0154] In one exemplary embodiment shown in FIG. 10A, the open aquatic environment DO level ranges from approximately 90% to approximately 150% DO, while the differentiated aquatic environment (i.e., containing the substrate to be protected) DO level ranges from about 50% to about 110% DO, which in this embodiment inhibits the ability of various organisms to contaminate the substrate (which is believed to substantially inhibit and / or prevent their ability to reproduce and / or colonize), and does not "dip" for extended periods of time to DO levels that may cause anoxia and promote corrosion of the substrate (although relatively short periods of periodic anoxic conditions may have occurred and may have been tolerable for various reasons). In various embodiments, including those shown in FIG. 10A-D, the presence of the enclosure may also mediate, "smooth" or "buffer" natural spikes and / or dips that may occur in the dissolved oxygen levels of the surrounding aqueous environment, which may further prevent and / or inhibit aquatic organisms from settling and / or reproducing on the protected substrate.

[0155] In at least one alternative embodiment, the enclosure design may include a wall material that may be permeable to one or more water chemistry factors, such as dissolved oxygen, while not facilitating the transport / passage of one or more other factors, chemicals, and / or even water itself, allowing sufficient levels of oxygen (or other chemical factors) to permeate the enclosure to produce some or all of the water chemistry differences described herein. Such alternative designs may have some potential to produce the various biofouling improvements disclosed herein.

[0156] In various other alternative embodiments, a particular enclosure design may include features that supplement various water chemistry components within the enclosure (e.g., dissolved oxygen, etc.) to obtain the desired fouling protection. For example, an enclosure having walls that are somewhat less permeable than optimal levels may include a supplemental source of dissolved oxygen, which may be utilized to maintain dissolved oxygen levels within the enclosure above undesirable anaerobic levels. Alternatively, an embodiment of the enclosure may include a supplemental fluid supply pump, or even an externally mounted "propeller" that may be activated to induce additional fluid outside the enclosure to pass through and / or into the enclosure, thereby providing additional supplemental dissolved oxygen and / or waste removal from the enclosure, and the pump / propeller may be activated and / or deactivated periodically and / or based on various measurements of water chemistry factors obtained within the enclosure, including water chemistry factors directly affected by the enclosure design and placement, as well as changes in water chemistry factors that may result from one or more water chemistry factors directly altered by the presence of the enclosure. Alternatively, a supplemental pump and / or pumping system may be utilized to pump water directly into and / or out of the enclosure or bounded body of water without the water passing through a permeable enclosure wall.

[0157] 31 illustrates one exemplary embodiment of an aqueous flow mechanism of a supplemental pumping system 3100 for adding and / or removing aqueous liquids and / or other materials or substances to / from an enclosed environment within an enclosure 3110. In this embodiment, the enclosure includes an exterior wall or boundary, which in some embodiments may include one or more permeable walls and in other embodiments may include one or more semi-permeable and / or non-permeable walls (some embodiments may include some or all walls of the enclosure that are non-permeable). A pumping mechanism 3120 may be provided having a flow cavity or intake 3130 and an intake pipe 3140, the pump further including an outlet 3160 and an outlet pipe or flow cavity or flow channel pipe 3170 extending from an outlet of the pump, through at least one wall of the enclosure, and through / into the aqueous environment within the enclosure. In various embodiments, at least some of the flow cavity portions 3180 of the outlet tube may extend some distance within the enclosure, with the outlet potentially located proximally and / or distally from the protected substrate (not shown) and / or one or more enclosure walls of the enclosure. In use, the pumping mechanism may be activated to supply outside water into the housing in a desired manner, and / or the pumping operation may be reversed to draw water from the enclosure to be discharged in the environment outside the enclosure. Alternatively, the pumping mechanism may be utilized to supply additional oxygen or other water chemical composition factors to the enclosed environment. If desired, some or all of the pumping mechanism and / or the flow cavity and / or the water intake 3130 may be located within the enclosure, or alternatively within and / or through some portion of the enclosure wall, or may be located outside the enclosure, if desired. In another embodiment, the aqueous flow feature may be a propeller system, a petal system, a flow pipe, a flow flume, or a flow tunnel that may be used in a similar manner to move water or create desired flow characteristics as a pump system.

[0158] Instead of and / or in addition to reducing the dissolved oxygen levels in the water contained within the enclosure, a wide variety of other water chemistry factors can be affected by the design and placement of the enclosure embodiments described herein, including water chemistry factors that can significantly slow and / or prevent fouling of the protected substrate. For example, when oxygen is depleted within the enclosure, some species of bacteria naturally occurring within the enclosure will first convert to the next best electron acceptor, which is typically nitrate in seawater. Denitrification will occur and nitrate will be consumed fairly quickly. After reducing some other trace elements, these bacteria will eventually convert to reducing sulfate, resulting in the by-product of hydrogen sulfide (H2S), a chemical toxicity to most biota and the cause of the characteristic "rotten egg" odor. This elevated level of hydrogen sulfide within the enclosure, among other chemicals, can then inhibit fouling of the substrate in a desired manner, as described herein. Additionally, hydrogen sulfide within the enclosure may also leach through the walls of the enclosure (i.e., accompanied by the bulk flow of water out of the enclosure), potentially inhibiting fouling growth within the pores and / or on the exterior surfaces of the enclosure.

[0159] In addition to creating localized conditions that inhibit fouling of the protected substrate contained within the enclosure, the various embodiments of the enclosure described herein are also very environmentally friendly in that any toxic and / or unpleasant conditions created within the enclosure are quickly neutralized outside the enclosure. For example, it can be assumed that when 1 ml of fluid enters the enclosure through an opening, approximately 1 ml of the enclosure fluid will be displaced outside the enclosure to the external environment. This displaced fluid will typically contain components that are toxic and / or unpleasant to marine life (which preferably reduces and / or prevents fouling from adhering to the substrate within the enclosure). However, once outside the enclosure, these components are quickly decomposed, oxidized, neutralized, metabolized, and / or diluted by a wide variety of naturally occurring mechanisms in the external aqueous environment and generally do not cause lasting effects in the aquatic environment, even if in close proximity to the enclosure itself. This is highly preferable over existing anti-fouling devices and / or paints that incorporate high levels of biocides and / or other agents, some of which are highly toxic to many forms of life (including fish and humans and / or other mammals) and can persist for decades in the marine environment.

[0160] In various alternative embodiments, the enclosure wall may incorporate supplemental biocides or other chemical(s) or compound(s) that may inhibit and / or prevent fouling on the surface and / or within the pores of the enclosure. In various embodiments, the biocide or other chemical(s) / compound(s) has primary biocidal activity limited to the surface and / or within the pores of the enclosure fabric, with very low and / or non-existent levels of biocide leaching into and / or outside the enclosure. In such cases, the biocide desirably protects the enclosure from fouling, while the enclosure, in turn, protects the substrate from fouling.

[0161] Various test enclosure designs were highly effective in providing biofouling protection to substrates under various daily and / or seasonal water conditions. For example, an enclosure incorporating a permeable fabric wall of spun polyester with a biocide coating was submerged in seawater and the dissolved oxygen levels of the aqueous environment inside and outside the enclosure were measured and tabulated. Figure 10A illustrates frequent sampling (i.e., every 15 minutes) of dissolved oxygen levels over a three day period in spring / early summer, which exhibited the diurnal variation of dissolved oxygen inside and outside the enclosure (i.e., light and dark areas reflect day and night). In this figure, it can be seen that the dissolved oxygen levels inside the enclosure typically lagged or "tracked" (i.e., at a lower level) the dissolved oxygen levels of the outside aqueous environment during the day and night sequence, and the DO inside the enclosure appeared "smoother" or more buffered than the DO of the outside environment. In contrast, Figure 10B illustrates a similar sampling of dissolved oxygen levels over a three day period in late summer / early fall, where the dissolved oxygen levels within the enclosure could often be equal to or greater than those of the surrounding environment, with the enclosure providing a "buffer" to the DO levels. In all cases, the enclosure was successful in limiting and / or preventing biofouling of the protected substrate, even as the relative levels of dissolved oxygen within and / or outside the enclosure changed.

[0162] 11 illustrates an exemplary cross-sectional view of a substrate 1900 and associated enclosure wall 1910 within an aqueous environment 1915. In this embodiment, the dissolved oxygen level 1920, shown by the dotted line, may be equal to and / or comparable to the DO of the surrounding aqueous environment at the boundary of the enclosure (although in some embodiments, the dissolved oxygen level may measurably decrease during passage through the enclosure wall 1910), and this DO level may begin to decrease progressively in the enclosure liquid (following along the level line 1920) as the measurement sensor (not shown) moves further into the differentiated environment 1930 toward the substrate, with the DO level desirably reaching a lower and / or lowest DO level reading proximate the substrate surface 1940. In various embodiments, the change in DO percentage from the liquid within the inner wall to the liquid near the substrate surface may be only a 1 or 2 percent change, while in other embodiments, this DO change may be very significant, such as a 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, and 25% or more difference in DO between the inner wall reading and the substrate surface reading.

[0163] Chemical composition of water In various embodiments, the design and positioning of the protective enclosure around the substrate may desirably alter various water chemical composition characteristics and / or components of the enclosed environment to a significant extent compared to those of the open aqueous environment. In various cases, the enclosure may induce some water chemical composition characteristics to be "different" compared to the surrounding aqueous environment, while other water chemical composition characteristics may remain the same as the surrounding aqueous environment. For example, while dissolved oxygen levels may often be "different" between the separated and open environments, the temperature, salinity, and / or pH levels in the separated and open environments may be similar or the same. Desirably, the enclosure may affect some water chemical composition characteristics in a desired manner, while leaving other water chemical composition characteristics minimally affected and / or "untouched" compared to those of the surrounding open aqueous environment. Some exemplary water chemical composition characteristics that may potentially "vary" and / or remain the same (i.e., depending on enclosure design and / or other environmental factors such as location and / or season) may include dissolved oxygen, pH, total dissolved nitrogen, ammonium, nitrate, nitrite, orthophosphate, total dissolved phosphate, silica, salinity, temperature, turbidity, chlorophyll, etc.

[0164] In some exemplary embodiments, measures of one or more water chemical composition characteristics may be "different" inside the enclosure compared to comparable measurements outside the enclosure (which may include measurements only 1 or 2 inches or more from the enclosure exterior wall, or at some distance away from the enclosure, such as 1, 2, 3, 5, 10, 20 feet or more to account for potential leaching outside the enclosure). Such "differences" may include 0.1% or more difference between inside / outside measurements, or 2% or more difference between inside / outside measurements, or 5% or more difference between inside / outside measurements, or 8% or more difference between inside / outside measurements, or 10% or more difference between inside / outside measurements, or 15% or more difference, or 25% or more difference, or even h50% or more difference, or 100% or more difference. Additionally, such differences may be for multiple chemical factors with unequal differences, or may include an increase in one factor and a decrease in another. Combinations of all such described water chemistry factors are contemplated, including situations in which some water chemistry factors remain essentially the same for some factors, while various differences may be observed for other factors.

[0165] Exemplary Water Chemistry Testing Protocol Hand-cast sensors are easy to use and very accurate in determining various water chemistry parameter measurements such as temperature, salinity, dissolved oxygen, and / or pH (among others). Such sensors are often tethered and equipped with a readout screen. If readings are to be taken over a relatively short time frame (minutes to hours), readings between samples can be roughly comparable without worrying about calibration concerns. If two or more probes are to be deployed simultaneously, it can be convenient to bundle them together using Velcro strips or cable ties.

[0166] When working with sensors, calibration of the handheld units should be performed against a schedule according to the manufacturer's specifications. During calibration, reliability solutions may be used as spot checks for some sensors. It is important to check handheld sensors before entering the field (battery life, reliability solutions, etc.). Prepare to take readings by unboxing the units, straightening the cables, bundling the sensors if using more than one, and marking the desired water depth (standard for static submersion is 1 / 2 meter) on the cables. Power on each handheld unit and place the probe(s) at the desired location, making sure the probe is at the desired depth. Wait for the probes to equilibrate; if equilibrium is not reached, spot readings may not be sufficient to capture differences between samples and continuous monitoring equipment may be required. Record the values ​​and repeat each asset of the steps until all desired locations have been tested. Once testing is completed, rinse the probes and cables before replacing the protective caps / bottles and allow the instruments to dry before being placed back in their respective boxes.

[0167] Exemplary Water Analysis Protocol In various embodiments, it may be desirable to quantify the difference in water inside and outside a fouling prevention enclosure, such as those described herein, including measurement readings of dissolved oxygen (DO), pH, and / or salinity. In such cases, DO (YSI, ProODO), pH (YSI, Pro10), and salinity (YSI, Pro30) may be measured using a YSI single parameter dropsonde using the following method: (1) calibrate the YSI sensor according to manufacturer's specifications, (2) place the YSI probe 0.5 m (18 inches) below the water surface, (3) allow the probe to stabilize before recording measurements, (4) record the DO, pH, or salinity value along with the water location, date and time, and (5) record the water temperature value along with the water location, date and time.

[0168] Exemplary Water Sample Collection for Water Chemical Composition Testing In various embodiments, it may be desirable to collect water samples for analysis of the water's chemical composition, including (1) nutrient testing and (2) alkalinity testing. The water collection apparatus may be a modified design of a standard 600 mL water collection apparatus using the following method: (1) use one water collection apparatus for each water sample. The water collection apparatus may consist of a 1-foot-long, 1-inch-diameter PVC pipe for water collection, attached to a 3-foot-long, 1-inch-diameter PVC pipe for handling using a slip coupler. A plug consisting of a rubber cork stopper and a stainless steel eye bolt is hung on the water collection end by a stainless steel ring on the opposite end of the water collection apparatus using 50 lb test nylon fishing line, (2) sanitize the water collection apparatus before use. Rinse all apparatus parts that encounter the water sample, the 1-inch-diameter PVC pipe, plug, fishing line with filtered water and soak in DI water for at least 12 hours, then dry. The apparatus handle and coupler should be rinsed with filtered water, and (3) sanitize all items that encounter the water sample during testing. Rinse the sampling bottle (250 mL), alkalinity analysis bottle (8 mL), funnel, and filtration syringe with filtered water, soak in DI water for at least 12 hours, then dry. Soak the nutrient analysis bottle (125 mL) in 10% HCL solution for at least 12 hours. Rinse twice in DI water, then dry, (4) Submerge the water collection device 12 inches below the water surface or when the slip coupler is just above the water surface to collect the water sample. Lift the stainless steel ring on the device handle to close the plug and collect the water sample. Ensure that the plug is fully and tightly locked before removing the device from the water. Remove the device from the water, (5) Place the water collection device over a clean funnel and collection bottle. Carefully and slowly open the plug by releasing the stainless steel ring and transfer the water sample from the water collection device to the collection bottle. Store the water sample on ice.

[0169] In some situations, immediate testing of collected water samples may not be possible, therefore, the following methods may be used to filter and store water samples for up to 28 days: (1) filter collected water samples. For dissolved chemical and alkalinity testing, filter water samples using a syringe polypropylene filter (part number 6788-2504, Whatman) with a pore size of 0.45 μm. For nutrient testing, 125 mL of filtered water may be required. For alkalinity testing, 8 mL of filtered water may be required, (2) freeze unacidified filtered water samples at -20°C for storage up to 28 days. (Strickland and Parsons, 1972, Grasshoff et al., 1999, Venrick and Hayward, 1985). Store water samples at -20°C for nutrient analysis. Store water samples at 4°C for alkalinity analysis.

[0170] In various embodiments, it may be desirable to quantify the difference in water inside and outside of an anti-fouling enclosure, such as those described herein, including measurement readings of Total Dissolved Nitrogen (TDN), Ammonium, Nitrate + Nitrite, Orthophosphate, Total Dissolved Phosphorus (TDP), and / or Silica. In many cases, the manufacturer's standard method may be used for dissolved chemical testing using a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer, following the procedure below:

[0171] For the analysis of TDN, ammonium, and nitrate+nitrite, the following method may be applied: (1) obtain a filtered water sample, (2) prepare a reference standard from RICCA ammonium (R0692500, RICCA Chemical Company), and (3) analyze the reference standard in duplicate to calibrate the absorbance readings at 540 nm on the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer. All standard absorbance values ​​should be within 10% of the known concentrations. (4) For the analysis of TDN, ammonium, and nitrate+nitrite, follow the manufacturer's method G-218-98 (SOP FIT-5008-TDN). The filtered water samples are passed over a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer to reduce nitrogen using a cadmium column, and the resulting nitrite is reacted with a diazo compound and N-(1-naphthyl)ethylenediamine dihydrochloride to form a pink azo dye, which is then measured for absorbance at 540 nm (5). The analytical precision (RSD) is approximately 2%.

[0172] For the analysis of orthophosphate, the following method may be applied: (1) obtain a filtered water sample, (2) prepare a reference standard from NIST traceable Dionex 5-Anion (Fisher Scientific), (3) analyze the reference standard to calibrate the absorbance readings at 880 nm on a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer. All standard absorbance values ​​should be within the 95% confidence interval of the standard, (4) follow the manufacturer's method SEAL Analytical G-297-03 for the analysis of orthophosphate. Pass the filtered water sample over the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer to determine the absorbance at 880 nm of the phospho-molybdenum blue complex formed when orthophosphate reacts with ascorbic acid, molybdate, and antimony, and (5) record the absorbance value. The analytical precision (RSD) is approximately 1% on average.

[0173] For the analysis of TDP, the following method may be applied: (1) obtain a filtered water sample, (2) prepare a reference standard from NIST traceable Dionex 5-Anion (Fisher Scientific), (3) analyze the reference standard to calibrate the absorbance readings at 880 nm on a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer. All standard absorbance values ​​should be within 10% of the known concentration, (4) follow manufacturer's method G-219-98 (SOP FIT-5008-TDP) for TDP. Run the filtered water sample over the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer to determine the absorbance at 880 nm of the phospho-molybdenum blue complex formed when orthophosphate reacts with ascorbic acid, molybdate, and antimony, and (5) record the absorbance value. The analytical precision (RSD) is approximately 3% on average.

[0174] For the analysis of silica, the following method may be applied: (1) obtain a filtered water sample; (2) analyze a sodium silicate reference standard (Part Number SS465, Fisher Scientific) to calibrate the absorbance readings at 820 nm on a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer; prepare a standard curve using the absorbance values ​​and known concentrations of the analyzed reference standard; (3) follow the manufacturer's method, SEAL Analysis G-177-96, for silica; pass the filtered water sample over the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer to determine the absorbance at 820 nm of the molybdenum blue complex formed when ammonium molybdate is added to the filtered water sample to obtain silicomolybdate and then reduced using ascorbic acid; (4) record the absorbance value. Compare the measured absorbance value with that of the reference standard curve to determine the concentration of silica in the filtered water sample. The average analytical precision (RSD) is approximately 3%.

[0175] To determine calcium carbonate levels, the alkalinity of the filtered water sample can be measured, which corresponds to the level of calcium carbonate in the sample. A standard method (APHA Method 2320-B: Standard Methods for the Examination of Water and Wastewater) can be used for testing utilizing the Gran function, following the following method: (1) obtain a filtered water sample, (2) obtain a reference seawater solution (OSIL, UK), and (3) analyze the reference standard for calibration. A standard curve is prepared using the alkalinity values ​​and known concentrations of the analyzed reference standard. All concentrations should be within the 95% confidence interval, (4) follow the standard method (2320-B) for alkalinity titration. Using the Gran function, the filtered water sample is titrated with 0.01N HCL, (5) the alkalinity is determined using the Gran function. The alkalinity (mg CaCO3 / L) is directly proportional to the amount of acid added during the titration, and (6) record the alkalinity value.

[0176] For various tests, enclosure embodiments with different size and / or shape structures or different materials were tested to determine whether the presence of the enclosure reduces, reduces, eliminates, inhibits, and / or prevents the establishment of macrofouling, including performing a visual comparison of the biofilm formed within the enclosure compared to the open water, and comparing the water quality and water chemistry within the enclosure to the open water. Table 5A shows the results of the saltwater tests in tabular form, indicating that ammonium, nitrate + nitrite (N+N), total dissolved nitrogen (TDN), dissolved organic nitrogen (DON), phosphate, and silica were all significantly different between the enclosure and open samples at different points during sampling, and Table 5B shows additional chemical measurements such as temperature, salinity, dissolved oxygen, and pH. Results showed that ammonium was significantly higher inside the enclosure on day 14 (6 / 22 / 18) and day 30 (7 / 9 / 18), and N+N was significantly higher inside the enclosure on day 1 (6 / 9 / 18), day 3 (6 / 11 / 19), and months 10 (4 / 15 / 19), and 12 (6 / 24 / 19). TDN and DON were significantly higher in the open samples on day 7, but switched to being higher inside the enclosure on days 14 and 30. Phosphate was significantly higher inside the enclosure on days 3, 7, 14, and 30, and months 10 and 12. Silica was significantly higher in the open samples on days 1, 3, and 14, but was higher inside the enclosure on day 30. [Table 6] [Table 7]

[0177] Various conclusions emerged from the data, including the following: (1) Dissolved inorganic nitrogen (N+N and ammonium) was higher inside the enclosure, while dissolved organic nitrogen (amino acids, urea) was higher outside the enclosure by day 7. This may indicate higher biological activity outside the enclosure by bacteria, cyanobacteria, and phytoplankton that use inorganic nitrogen for growth and produce organic nitrogen (by decay and excretion). Biofilm results from this experiment (observationally) and DNA results from previous testing verified this hypothesis. Overall dissolved organic nitrogen (DON) inside the enclosure remained similar throughout the second half of the experiment, while open DON fluctuated, likely due to the natural cycling of nitrogen within the seaport, sequestered or buffered by the enclosure; (2) phosphate levels were higher within the enclosure than in the open water, likely due to higher biological activity using phosphorus outside the enclosure; and / or (3) silica levels were higher outside the enclosure until day 14, likely due to higher activity and turnover of diatoms outside the enclosure, which switched on day 30. Overall silica levels within the enclosure were reasonably similar over time, while open levels of silica fluctuated. This variability likely indicated cycling within the open water, i.e., sequestered or buffered by the enclosure, as silica was used by diatoms.

[0178] In another example, the water chemistry and quality was observed in various enclosure embodiments. The purpose of this saltwater test was to examine the difference in water chemistry between the water in various sized enclosures (1, 2, and 4 feet diameter) and the open water. Table 5C shows the results of the 12-month saltwater test in tabular form, indicating that ammonium, nitrate + nitrite (N+N), total dissolved nitrogen (TDN), dissolved organic nitrogen (DON), phosphate, silica, and alkalinity were all significantly different between the enclosure and open samples at different points during sampling, and Table 5D shows additional chemical measurements such as temperature, salinity, dissolved oxygen, and pH. [Table 8] [Table 9]

[0179] Test results showed that dissolved oxygen and pH were significantly higher in the open water compared to the water inside the enclosure for all enclosure sizes (1, 2, and 4 foot diameter). N+N, TDN, phosphate, and silica were all significantly different in the water inside the enclosure compared to the open water. Alkalinity, N+N, TDN, and phosphate were all significantly higher inside the enclosure compared to the open water. This data shows similar trends to other water chemistry tests in saltwater. The increased water chemistry concentrations inside the enclosure compared to the open water may indicate higher biological activity outside the enclosure due to bacteria, cyanobacteria, and phytoplankton using the available nutrients for growth.

[0180] Additionally, some of the results of these water chemistry studies suggest that various enclosure embodiments may cause respiration or metabolism to be higher or exceed photosynthesis within the enclosure structure. This effect may occur due to reduced levels of dissolved oxygen or other water chemistry parameters caused by the enclosure structure. Differences in dissolved oxygen inside the enclosure may likely be related to light limitations within the enclosure. Slight day-to-day measurement variability may be related to the timing of sampling (i.e., morning sampling vs. evening sampling), as seen in Figures 10A and 10B.

[0181] The effect of respiration over photosynthesis within the enclosure structure can be demonstrated based on the phosphate results. Phosphate concentrations in the enclosure waters are consistently higher than in the open waters. Based on the phosphate cycle and the fact that phosphate is known to exchange between particles and dissolved phases, diffusion may be acting to restore equilibrium in the chemical composition of the water on each side of the permeable enclosure. The greater the difference in conditions of the water within the enclosure compared to the open water conditions, the more diffusion will generally be acting to restore equilibrium. Therefore, phosphate should likely continue to increase within the enclosure waters, but may be lost due to diffusion.

[0182] In one embodiment, the enclosure structure provides anti-fouling protection within its boundaries through the initial establishment of a nitrification and denitrification rich environment. During this test, the data consistently show higher ammonium in the water within the enclosure structure. As shown in FIG. 12A, the initial nitrogen product of respiration is reduced nitrogen or ammonium. After four days of submersion, the internal environment becomes hypoxic, resulting in the formation of non-ionized ammoniacal nitrogen (NH3-N), which is toxic to marine life within the boundaries of the device. In addition to the production of NH3-N, it is possible that nitrite (NO2) and other toxic reactive nitrogen molecules may also be generated within the media-filled boundaries of the enclosure structure. This effect appears to be enhanced as the exterior of the enclosure becomes progressively more contaminated. Additionally, microbial biofilms that form within and on the surfaces of the enclosure device may contribute to the universal nitrification and denitrification pathways.

[0183] Test data often demonstrates that nitrate + nitrite (N+N) was higher in the water within the enclosure structure when compared to the open water. This result may be related to nitrification of ammonia over oxic conditions. In some embodiments, the dissolved oxygen is lower in the bag, but may not be low enough to inhibit nitrification, and the ammonium source may come from respiration. In some embodiments, the dissolved oxygen is likely not low enough to promote dissimilatory nitrate reduction (DNRA) to ammonium or ammonification of nitrate / nitrite, but it is possible that an anoxic microenvironment (dissolved oxygen concentration in the water less than 0.5 mg / L) exists in the bag that may promote DNRA. DNRA is the result of anaerobic respiration of microorganisms that use nitrate as an electron acceptor and reduce it to nitrite and then ammonium, as shown in FIG. 12A.

[0184] Additionally, total dissolved nitrogen (TDN) was typically higher in the enclosed water compared to the open water during saltwater testing. This result is consistent with the high microbial respiration and dissolved nitrogen released from the particles as they decompose. In some embodiments, the settling of particles in the low energy environment of the enclosure results in a settling source of dissolved nutrients to the enclosed water. This settling, dead, dying, or decomposed particles at the bottom of the enclosure may, in some embodiments, explain the difference in chemical composition and water quality of the water in the enclosure and the open water. These decomposed particles or settling may be consuming most of the dissolved oxygen in the enclosure structure.

[0185] When respiration releases CO2, this can result in a drop in pH and drive or reduction to carbonate. By creating an increase in carbonic acid in seawater, the water results in more acidic conditions and therefore a lower pH reading. Organisms respond quickly to the decrease in dissolved oxygen, especially when it begins to reach levels of 3 mg / L or 2 mg / L. This difference in water can cause organisms to not produce shells or to produce thinner shells. Additionally, this difference may not allow organisms to settle or swim and / or move if the difference in oxygen is too great.

[0186] The chemical composition of carbonates also appears to be modified within the boundaries of the enclosure device, with entrained waters becoming more corrosive to calcium carbonate mineralization over time. To allow for comparison of the open and enclosed waters sampled during the experiment, the NOAA CO2 Sys program, which evaluates changes in the chemical composition of carbonate waters, can be used to generate a single integrated measurement, the aragonite saturation index (Omega-Ω), for each water mass sampled at a particular time. The aragonite (aragonite is a crystallized form of calcium carbonate mineral) saturation index (Ω) is a dimensionless number that indicates the degree of supersaturation of calcium carbonate in seawater. Values ​​above 1 indicate supersaturation (aragonite will grow in size) and values ​​below 1 indicate undersaturation (aragonite will dissolve). Chemical oceanographers rely on the Omega value to ascertain the magnitude and trend of ocean acidification for a given ocean water mass. A decreasing trend in Ω is considered to be a corrosive threat to calcium carbonate formation. The determination of Ω depends on salinity, water temperature, depth (as pressure), phosphate, silica, ammonium, alkalinity, and pH. The integration of all these parameters into a single unified scale allowed a direct comparison of water mass samples taken over the course of the settlement experiment (see Figure 12B).

[0187] The Redfield ratio or Redfield stoichiometry was analyzed to understand the atomic ratios of carbon, nitrogen, and phosphate found in marine phytoplankton within the waters inside the enclosure structure and in the open waters. According to this theory, nutrient limitation was investigated in saltwater with a ratio of carbon:nitrogen:phosphate = 106:16:1. Based on the increased concentration levels of ammonium (i.e., nitrogen) and phosphate within the waters inside the enclosure, it was determined that in some embodiments, there may not be any nutrient limitation within the waters of the enclosure compared to the open waters.

[0188] In one embodiment, the enclosure may serve as a substratum for bacterial colonization and macrofouling establishment. Free exchange of dissolved oxygen, ammonia, nitrite, nitrate may occur throughout the permeable enclosure. In one embodiment, macrofouler and / or bacterial biofilm respiration may account for the majority of oxygen and / or chemical nutrient uptake across the permeable enclosure. Consumption of oxygen, nitrogen, phosphate, and other nutrients may occur by the biofilm as water passes or exchanges into the permeable enclosure. Bacterial biofilms may begin to contribute to the OUR of the enclosure until the enclosure water reaches a steady state in terms of biofilm oxygen uptake rate (OUR). In one example, steady state of nutrients in the water within the enclosure for the biofilm may occur in less than 12 months, less than 6 months, less than 3 months, 1-60 days, 1-30 days, or 58 days. Bacterial biofilms growing in or on the surfaces of the enclosure and invertebrate macrofoulers growing on the exterior surfaces of the enclosure are responsible in many embodiments for establishing and maintaining a fixed film barrier, which can provide significant anti-fouling protection. In some embodiments, the film barrier can be a mechanism that prevents biofouling from occurring in the water compartment enclosed by the fabric structure.

[0189] In general, unionized ammonia as NH3-N is highly toxic to both aquatic and marine species at levels approaching 100 μg / L (ppb). The NH3-N concentrations observed from within the device after 7 days were approaching 20% ​​of the toxic level and may have been higher. Another potential contributor to toxicity from within the device is nitrite (NO2), which is considered toxic at 1 ppm levels. During the saltwater experiments, the dissolved oxygen within the device did not drop to hypoxic levels (hypoxia occurs at less than 2 mg / L dissolved O2), but did trend downward. This mechanism of action of the water chemistry is also relevant for freshwater applications as it does not depend on any particular microbial biofilm.

[0190] In another example, freshwater samples of water chemistry and quality were collected and analyzed from an experiment at the University of Wisconsin at Milwaukee (UWM). An enclosure structure was deployed to protect valves and boats from fouling in the Great Lakes. After one month of submersion, water samples were collected in the enclosure and in the open water. These results are presented in Tables 5E-5G. As shown in Table 5E, ammonium, nitrite, N+N, TDN, DON, phosphate, and silica were significantly different in the freshwater, and most of the chemicals were significantly different at two separate locations in the Great Lakes. The freshwater at the marina (M) demonstrated significantly higher ammonium, TDN, and phosphate concentrations in the waters inside the enclosure structure compared to the open water. Nitrite, N+N, phosphate, and silica concentrations were all significantly higher in the waters inside the enclosure compared to the open waters of the UWM seawall. These results may indicate higher biological activity outside the enclosure structure, with bacteria, cyanobacteria, and phytoplankton using the available nutrients for growth. [Table 10] [Table 11] [Table 12]

[0191] Table 5F shows one month of freshwater temperature, conductivity, dissolved oxygen, and pH results for two Great Lakes locations, the Marina (M) and the UWM seawall (UWM). The dissolved oxygen concentration in the water inside the enclosure structure is different from the dissolved oxygen in the open freshwater at each location. In a separate freshwater experiment, water chemistry samples were analyzed for the entrained water inside the enclosure protecting the metal valve, and for the open water at a similar location on the Great Lakes two months later. Freshwater temperature, conductivity, dissolved oxygen (OD), pH, turbidity, and chlorophyll test results are presented in Table 6G. Dissolved oxygen, pH, and chlorophyll show significant differences between the waters inside the enclosure and the open water. Dissolved oxygen and pH are lower in the local aquatic environment (waters inside the enclosure) compared to the open water. Chlorophyll readings are significantly higher in the local aquatic environment compared to the open water. The differences in dissolved oxygen, pH, and chlorophyll can be explained with the understanding that bacterial respiration in an oxic environment is greater or more prominent than algal photosynthesis or nutrient uptake. Similar conclusions have been made for freshwater studies as for saltwater studies.

[0192] In another exemplary embodiment shown in Tables 6A and 6B below, water chemistry results were obtained for various enclosures incorporating spun polyester fabrics coated with 154 (3500 cP, original formula) or 153 (3500 cP, formula without acrylic) water-based biocidal coatings using a commercial printing process with 30 or 40 screens (with or without vacuum), and open water samples. Overall, a total of eight treatments were tested: 154-30v, 154-30nv, 154-40v, 154-40nv, 153-30v, 153-30nv, 153-40v, and 153-40nv, and an open water sample (control). The permeability of each fabric type was collected using the disclosed methodology, and the following sample lookup table is provided. [Table 13]

[0193] Water samples were collected from the low permeability enclosures, 154-30nv, 153-40nv, and 153-30nv, the high permeability enclosures, 153-40v and 154-40v, and the open water (control) using a water chemistry core sampler. The test results demonstrated observable differences in nutrient levels between the water samples collected from within the enclosures and the open water samples. The low permeability enclosures show a greater difference in nutrient content compared to the open water samples. In general, the nutrient content levels of the water were higher inside the enclosures compared to the open water. Additionally, the pH of the water within the enclosures compared to the pH of the open water was observed. Depending on the enclosure design, substrate composition and / or other goals, as well as various environmental and / or water conditions, the pH within the enclosure may be higher than that of the open environment, or the water contained within the novel enclosure may reflect a lower or more acidic pH than the open water, which may constitute a significant water chemical composition "difference" of the differentiated environments that contributes to the biofouling effects of some enclosure designs. [Table 14]

[0194] Biofilm and / or film formation In various aspects of the invention, proper design and use of the enclosure as described herein can create a "different environment" within the enclosure that affects and / or induces the formation of a biological coating, layer and / or biofilm on the surface of the substrate that effectively reduces and / or prevents the establishment of biofouling organisms on the substrate. In some aspects of the invention, this reduction and / or prevention can be due to one or more localized settlement cues that discourage (e.g., reduce, minimize, or prevent) the establishment of biofouling organism larvae, which can include the abstention of settlement on the substrate, while in other aspects of the invention, the reduction and / or prevention can be due to the absence of one or more positive settlement cues that promote the establishment of biofouling organism larvae, which can also reduce settlement on the substrate (and / or various combinations of the presence and / or absence of settlement cues can be involved in various embodiments). In another aspect of the invention, the enclosure may promote the growth of microorganisms that create one or more localized settlement cues that dissuade the larvae of biofouling organisms from settling within the differentiated aquatic environment created by the enclosure. In further aspects of the invention, the enclosure may promote the growth of microorganisms that create one or more localized settlement cues on and / or within the enclosure material itself that dissuade the larvae of biofouling organisms from settling. Thus, in these aspects of the invention, the larvae of biofouling organisms may be unable or unlikely to settle or attach to the submerged substrate or substrate portion(s) protected by the enclosure.

[0195] In various embodiments, the biofilm may be on a protected substrate and may form on the outside of the enclosure and / or on the inside of the enclosure. The biofilm at each location may vary based on the amount of bacteria, cyanobacteria, diatoms, various bacterial phyla, diversity, thickness, and completeness, as well as by other measures.

[0196] FIG. 14 illustrates one exemplary "standard" progression or colonization sequence that typically leads to the establishment of a fouling community on a substrate submerged in an aqueous medium such as seawater, saltwater, and / or freshwater. In this sequence, submersion of the substrate in the aqueous medium immediately initiates the physical process of polymer adsorption, followed by prokaryotic cells and bacteria that rapidly land, attach, and colonize on any surface within the marine environment. In some cases, the subsequent formation of a microbial biofilm may then promote the attachment of algal spores, protozoa, barnacle cyprids, and marine fungi, followed by the colonization of other marine invertebrate larvae and macroalgae, while in other cases, macrofoulers may colonize without a biofilm, yet some other macrofoulers may prefer cleaner surfaces.

[0197] Marine fouling is typically described as following four stages of ecosystem development. The chemistry of biofilm formation describes the initial steps prior to colonization. Within the first minute, van der Waals interactions cause the immersed surface to be coated with a conditioning film of organic polymers. Over the next 24 hours, this layer allows the process of bacterial attachment to occur, with both diatoms and bacteria (e.g., Vibrio alginolyticus, Pseudomonas putrefaciens) attaching and initiating the formation of a biofilm. By the end of the first week, the abundance of nutrients and ease of attachment to the biofilm allows the secondary colonizers of macroalgae (e.g., Enteromorpha intestinalis, Ulothrix) and protozoan (e.g., Vorticella, Zoothamnium sp.) spores to attach themselves. Within 2-3 weeks, the tertiary colonizers, macrofoulae, have attached. These include tunicates, mollusks, and sessile cnidarians.

[0198] However, when an enclosure as described herein is utilized, the biological colonization sequence on the substrate may be altered. For example, the biological colonization sequence on the substrate may be interrupted (disrupted, altered, etc.) to reduce and / or minimize settlement, recruitment, and eventual macrofouling of the protected substrate. Once positioned around the substrate, the permeable protective fabric wall of the enclosure may desirably filter and / or impede the passage of various micro- and / or macro-organisms into the enclosure, as well as potentially alter various aspects of the chemical composition of the water within the enclosure.

[0199] FIG. 15 generally graphically illustrates the various distributions of bacterial phyla within biofilms formed on substrates of open samples (six bars from the left) and on substrates within various enclosure embodiments in seawater (six bars from the right), and Table 7 (below) contains the underlying data illustrated in FIG. 15. The bacterial biofilms formed on substrates or other articles protected by the enclosure were significantly different from any natural biofilms that form on substrates or other objects in open water or other aqueous environments proximate to the protected article. In various embodiments, proper design and operation of the enclosure will desirably induce and / or enhance the growth and replication of specific combinations of microorganisms, many of which are typically found at different (i.e., often relatively low) levels in natural environments, and these combinations of microorganisms may have the ability to enhance certain "recruitment and colonization" behaviors to other organisms and to identify the surface of the substrate as less welcoming and / or "less desirable" (and signal this fact through various means).

[0200] DNA analysis confirmed that the surface biofilms forming on the PVC and bronze substrates inside the various protected enclosure embodiments were significantly different from those forming on similar substrates outside the enclosure, and this also applies to the biofilm-forming communities present within the enclosures, and to the biofilms forming in / on the interior wall surfaces of the enclosures. For example, the biofilms appearing on the PVC and bronze article coupons in open water were thicker and more diverse than the biofilms appearing on the PVC and bronze article coupons protected by the enclosures of the present invention. In addition, macrofouling was observed on the articles in open water, whereas little or no macrofouling was present on the substrates protected by the enclosures. In some embodiments, the biofilms on the enclosed substrates were less diverse than the open biofilms, with different amounts of diatoms, bacteria, cyanobacteria, and distribution of different bacterial phyla. In addition, the predominant bacterial phyla and bacterial distribution within each enclosure (and / or on each substrate) were significantly different for each enclosure design. For example, as best seen in Figure 15 and supported by the data in Table 7, the PVC substrates within the spun poly enclosure (three rightmost bars) were dominated by Proteobacteria (the larger grouping at the top of the bars) and Bacteroidetes (the second largest grouping toward the bottom of the bars). In contrast, the bronze substrates within the spun poly enclosure (bars 6-9) were dominated by Proteobacteria, and the much smaller remainder was dominated by Bacteroidetes. This distribution of the dominant bacterial phyla in the biofilms is for the open bronze bars (columns 1-3), open PVC bars (columns 4-6), enclosed bronze bars (columns 7-9), and enclosed PVC bars (columns 10-12). Additionally, the biofilm "integrity" of the enclosed substrates differed from the open samples in that the biofilm on some of the enclosed substrates appeared easier to remove and / or wash from the substrate surface compared to the open substrates. [Table 15]

[0201] In several experiments, various substrates were submerged in an aqueous environment (i.e., natural seawater), and some substrates were protected by an enclosure design such as that described herein for a three-week submersion period, at which point the substrates were removed from the seawater and the enclosures and resulting substrate surface biofilms (formed on these substrates during that time) were subjected to DNA analysis. Visual comparisons between bronze substrates protected by the enclosures compared to unprotected (i.e., open) bronze substrates demonstrated a significant reduction in fouling organisms on the protected substrates. Furthermore, biofilms formed on the open bars (i.e., unprotected PVC and bronze) demonstrated significantly thicker biofilms than those on the protected substrates. Additionally, one notable difference between the biofilms of the open and differentiated samples was the predominance of Proteobacteria and Bacteroidetes in the biofilms of the protected substrates, and the virtual absence of Verrucomicrobium and Actinobacteria in the protected biofilms. The predominance and / or absence of various bacteria in the novel and / or "artificial" or "synthetic" biofilms formed on substrates in the artificial "differentiated" environments formed by the novel enclosures are believed to be unique and significantly different artificial biofilms that acquire colonization cues that are different (and potentially disadvantageous) from those normal colonization cues presented by biofilm layers formed naturally in open aquatic environments, thereby reducing the chances of colonization and / or colonization of the substrate by micro- and / or macro-fouling media even in the absence of the enclosure (i.e., after the enclosure has been permanently and / or temporarily removed).

[0202] In another experimental test, a series of clear glass substrates were submerged in an aqueous environment and analyzed to determine the thickness and type of biofilm / fouling that formed on substrates protected and unprotected by novel enclosure designs such as those described herein for periods of 30 days, 8 months, and 12 months. The results of these tests concluded that no macrofouling colonization occurred on slides inside the novel enclosures during the entire 30-day test. In contrast, slides placed in open water continued to accumulate macrofouling through day 30. Macrofouling on the open slides consisted of hydroids, encrusted and dendritic bryozoans, barnacles, tubeworms, and sponges, with significantly higher colonization on the open slides beginning at day 14.

[0203] With regard to biofilms on various substrates, the unique biofilms on slides from inside the protective enclosure were determined to be too thin to be easily visible, and the presence of biofilm was indicated by small clumps of attached sediment. The appearance of the biofilms on these protected slides changed little from days 1 to 30. Conversely, the open slide biofilms after 30 days of submersion in saltwater underwent notable changes over the course of the experiment. On day 1, the biofilms were very light and similar to differentiated biofilms. However, by day 3, the open biofilms were dominated by marginatum (predatory ciliate protozoa that feed on biofilm). On day 7, the visible portion of the open biofilm consisted of diatoms, cyanobacteria, and microalgae, as well as microscopic motile organisms (ciliates, dinoflagellates, etc.) that feed on sessile biofilm organisms. These unprotected biofilms were thicker and more developed by day 14, with accumulation of filamentous algae. In addition, dissolved oxygen levels were significantly higher in the open water than in the novel enclosure on days 1, 7, and 14. Furthermore, liquid pH was significantly higher in the open water than in the novel enclosure from day 14 onwards.

[0204] After one year of submersion in salt water, glass substrates protected with fabric biofouling prevention enclosures were examined for biological colonization. After 12 months of submersion, no major or minor biofouling or biological colonization was present on the protected glass substrates, but biofilms had formed on glass substrates protected by fabric enclosures. The 12-month biofilms ranged from patchy, uneven, and discontinuous thin layers on some substrates to continuous thin layers extending completely across the entire surface on other substrates. These 12-month biofilm structures were more developed and complex compared to biofilms on glass substrates after 30 days, but biofilms on unprotected glass substrates after 30 days were exponentially more developed, complex, and thicker than biofilms on protected glass substrates after 12 months. No cyanobacteria or diatoms were present in the biofilms on protected glass substrates after 12 months, except for a few trapped (but uncolonized) central diatoms. The structure of the 12-month biofilm on protected glass substrates contained silt trapped in extracellular polymeric substances (EPS) and a small number of glass substrates contained low-coverage tubeworms (spirorbid and Hydroides sp.).

[0205] A wide variety of larval and / or other settlement cues exist, ranging from physical to biochemical. These cues indicate the presence of habitats favorable or unfavorable to larval settlement. Physical cues may include light and color, flow direction and speed, oxygen, orientation, texture, sound, and surface energy / wetness deposition. Other cues indicating the presence of predators or superior competitors may inhibit settlement. Existing fouling may promote or inhibit settlement, the effects of which may vary depending on the existing and settling species. For purposes of this disclosure, local settlement cues may refer to current conditions and past markers in the local aquatic environment that provide information to aquatic larvae that promote or discourage (including the absence of promotion) settlement in the local aquatic environment. In aspects of the invention, the enclosure, in conjunction with the substrate and / or distinct aquatic environment, defines a local aquatic environment that generates and / or enhances the formation of localized colonization cues that do not encourage and / or actively discourage colonization of aquatic organisms on the substrate and / or on / within the enclosure. In various embodiments of the invention, novel enclosures or other devices are provided that induce, enhance, enable, and / or promote at least one exogenous localized colonization cue formation.

[0206] Once a biofilm or other layer is present or established, with or without localized colonization cues, these cues may remain in / on the substrate (e.g., the surface is sufficiently protected by the enclosure) for a period of time after the enclosure is no longer engaged with or removed from the substrate. For example, once localized colonization cues become associated with or present on the substrate, the enclosure may be removed and / or damaged, and at least a portion of the localized colonization cues should remain on the substrate to provide a continuing signal to discourage and / or promote macrofouling organisms from settling. As an example, this preventative effect of the localized colonization cues may remain on the hull of a boat after the enclosure is removed (and / or damaged), continuing to discourage settlement. This settling abandonment may extend for a period of up to about 2 years, at least 1.5 years, at least 1 year, at least 9 months, at least 6 months, at least 3 months, at least 1 month, at least 1 week, at least 3 days, at least 1 day, and / or at least 12 hours. Additionally, the biofilm or other layer(s) formed thereon may be resistant to removal and thus provide continued protection against movable and / or mobile submerged and / or partially submerged surfaces and / or items, including items used to generate propulsion such as propeller vanes and / or shafts. Thus, the enclosures and processes of the present invention described herein may allow for "inoculation" of a substrate against biofouling, which inoculation may continue for some time due to the persistence effect of local colonization cues (LSCs).

[0207] In various embodiments, it is proposed that the changes in the chemical composition of the water, including all the parameters measured, may have been at least partially due to the accumulation of biofouling organisms on the exterior, interior, or within the fabric of the enclosure structure. In one embodiment, an external biofilm developed on the exterior surface of the enclosure structure accumulated and became noticeable by day 13, and matured and developed an organized structure by day 30. At these time points (days 13 and 30), dissolved oxygen and pH were significantly decreased inside the enclosure structure. In some exemplary embodiments, it is believed that dissolved oxygen and pH may be tied together, since microbial respiration within the enclosure structure is expected to lead to a decrease in oxygen and a relative increase in carbon dioxide. An increase in carbon dioxide in the water results in more acidic conditions, thus decreasing the pH in the water.

[0208] In some embodiments, biofilm components can be used as cues to appropriate colonization sites. Furthermore, the invertebrate larvae's bacterial cue receptors can be unique to each organism. For many organisms, larval colonization occurs in response to a surface biofilm. The difference between a biofilm on a substrate surface and a biofilm on an enclosure surface can cause an organism to colonize one biofilm and not the other. Preferably, colonization will occur on the biofilm on the enclosure surface and not on the biofilm on the substrate surface.

[0209] In at least one additional embodiment, the biofilm(s) on the surface of the enclosure structure may act as a "biofilter" and / or utilize or consume nutrients (i.e., oxygen, nitrogen, carbon, phosphates, etc.), thus allowing some or all of the nutrients to pass or move into the water inside the enclosure structure, which may demonstrate where water chemistry data indicates more respiration or nutrient uptake occurs in the open water when compared to the enclosed water within the structure. These two communities, the bacterial biofilm growing within the fabric and the invertebrate macrofouling growing on the exterior surface of the structure, may be involved in establishing and maintaining a fixed film barrier that provides anti-fouling protection, which is at least one mechanism that prevents biofouling within the compartment enclosed by the structure.

[0210] In another embodiment, one or more biofilms may be grown on the surface of the enclosure structure to protect the substrate and extend the life of the enclosure. These protective biofilms may be located on the exterior surface of the enclosure, on the interior surface of the enclosure, or may penetrate or be within the wall(s) of the enclosure. In some embodiments, a three-dimensional multifilament fiber enclosure structure may provide significantly more effective contact surface area than a flat surface, and therefore the biofilm present thereon may be significantly more active and / or optimized to provide greater protection.

[0211] Optional biocide coating and / or integration In some exemplary embodiments, the disclosed enclosures may not include and / or require the use of supplemental biocide and / or antifouling agent(s) for the enclosure to provide adequate biofouling protection to the enclosure material and / or substrate, which may include the use of unprotected fabric enclosures for a period of soaking when the fouling pressure may be such that the unprotected fabric is free of macrofouling and / or when an uncoated enclosure may be sufficient to provide protection to the contained substrate for a desired period of time. Similarly, the disclosed enclosures may provide protection for substrates against destructive and / or invasive organisms such as wood-boring fouling organisms (i.e., terredo bugs or "shipworms" and their associated bacteria) using a variety of enclosure designs, including tightly rolled enclosures, bag enclosure embodiments, and / or "skirt" enclosure embodiments that provide such protection to various degrees.

[0212] However, in various alternative optional embodiments, at least a portion of the surface of the enclosure wall structure may be impregnated, infused, and / or coated with a biocidal paint, coating, and / or additive. In some additional embodiments, biocide and / or anti-fouling agent(s) may be integrated into the enclosure wall and / or other portions to desirably protect the enclosure itself from undesirable fouling. In some exemplary embodiments, a fabric or material may act as a carrier for the biocide.

[0213] In general, biocides or other chemicals, compounds and / or microorganisms capable of exerting a destroying, deterring, neutralizing, and / or controlling effect on any undesirable or unwanted organisms by chemical or biological means may optionally be incorporated in and / or on some portion(s) of the material, such as during manufacture of the material or material components, or the biocides and the like may be introduced into the material after manufacture. Desirably, one or more biocides in / on the material will inhibit and / or prevent colonization of aquatic organisms on the exterior surface and / or within openings in the enclosure, as well as repel, incapacitate, impair, and / or weaken biofouling organisms small enough to attempt or successfully penetrate openings in the enclosure, such that the biofouling organisms are less able to reproduce within the artificial or synthetic local aquatic environment between the structure and the substrate. In various embodiments, the enclosure desirably incorporates materials that maintain sufficient strength and / or integrity to allow for protection and / or inhibition of biofouling (and / or allow for the formation of a desired artificial or synthetic localized aqueous environment) for a useful life of about 3-7 days or more, 7-15 days or more, 3-15 days or more, at least 1 month, at least 3 months, at least 6 months, at least 12 months, at least 2 years, at least 3 years, at least 4 years, and / or at least 5 years or more.

[0214] In at least one exemplary embodiment of the enclosure, the enclosure may incorporate a material that is coated, painted, and / or impregnated with a biocidal coating, which desirably adheres to and / or penetrates the material to a desired depth (which may include surface coatings of the material on only one side of the fabric, coatings that may penetrate 1%-99% of the way through the fabric, and coatings that may penetrate completely through the fabric and coat some or all of the opposing side of the fabric). Desirably, the biocide will reduce and / or prevent the type, rate, and / or extent of biofouling on the material and / or may have some detrimental effect on microorganisms that attempt to pass through openings in the material and enter the differentiated aqueous environment (and may also have some effect on microorganisms already present within the enclosure). In various embodiments, the presence of a biocide coating or paint along the three-dimensional "entry path" into the enclosure (i.e., as microorganisms pass through the openings and / or pores of the material) will desirably provide a greater surface area and prove more effective than the standard two-dimensional paint biocide coatings (i.e., hard planar coatings) utilized on rigid, submerged surfaces in marine applications today. In various aspects, particularly where the fabric substrate material is highly fibrillated and / or ciliated, a coating of such material may desirably provide a greater degree of "functional surface area" of the fabric for the biocide coating to adhere to, which desirably improves the potential for anti-biofouling effectiveness since organisms are more likely to be located near and / or come into contact with these small fibers (and any biocide paints, coatings, or additives present on or within them) as they pass through the fabric.

[0215] In various alternative embodiments, the enclosure may incorporate a material that is coated, painted, and / or impregnated with a biocidal coating (which may include a surface coating of the material on only one side of the fabric, as well as a surface coating from the front and / or back of the fabric that may extend into the pores of the fabric to some extent), which may include up to 5% in the pores of the fabric, up to 10% in the pores of the fabric, up to 15% in the pores of the fabric, up to 20% in the pores of the fabric, up to 25% in the pores of the fabric, up to 30% in the pores of the fabric, up to 35% in the pores of the fabric, , up to 40% within the pores of the fabric, up to 45% within the pores of the fabric, up to 50% within the pores of the fabric, up to 55% within the pores of the fabric, up to 60% within the pores of the fabric, up to 65% within the pores of the fabric, up to 70% within the pores of the fabric, up to 75% within the pores of the fabric, up to 80% within the pores of the fabric, up to 85% within the pores of the fabric, up to 90% within the pores of the fabric, up to 95% within the pores of the fabric, up to 99% within the pores of the fabric, up to 100% penetrating a path through the pores of the fabric and / or extending out from the pores onto the opposing surface of the fabric.

[0216] In various embodiments, the additional incorporation of the biocide coating or other coating / additive of some embodiments also desirably improves the durability and functional life of the enclosure and / or its components in that biofouling organisms and / or other harmful agents are inhibited and / or prevented from colonizing the flexible fabric and / or perforations therein for a period of time following submersion, thereby desirably maintaining the flexible perforated nature of the enclosure walls, and its attendant benefits. If the biocide is primarily retained in close proximity to the fabric substrate (i.e., very low or no biocide leaching levels), the biocide will desirably significantly inhibit biofouling of the enclosure walls, while the presence of the enclosure and the "distinct aqueous environment" created therein will reduce and / or inhibit biofouling of the protected substrate. In various exemplary embodiments, the biocide can have extremely low and / or undetectable levels (i.e., less than 30 ng / L) in the water within the distinct aqueous environment and / or open water adjacent to the enclosure and still remain highly effective in protecting the enclosure and / or substrate from biofouling. As shown in Figure 28A, biocide release rates from the enclosure were detected to be 0.2-2 ppm or less in artificial seawater over 7 days, and low local concentrations (i.e., biocide release rates) were detected to be 0.2-2 ppm or less in artificial seawater over 7 days and were effective in protecting the enclosure from biofouling.

[0217] A wide variety of supplemental coatings incorporating different biocides and / or other dispensing and / or eluting materials may be incorporated into a given enclosure design to provide different anti-fouling benefits. For example, Figures 28B and 28C illustrate various biocide release rates for various coatings and / or enclosure designs, including coatings that release econea and / or pyrithione in various amounts and / or timing, including embodiments having an initially high release rate that decreases significantly after only a few days and / or weeks of submersion, as well as other embodiments having an initially low release rate that increases with submersion time.

[0218] In at least one exemplary embodiment, the enclosure material may comprise a spun polyester fabric having a surface and / or subsurface coating of a commercially available biocidal coating, including water-based and / or solvent-based coatings containing a registered biocide, the coating being applied to the fabric by virtually any means known in the art, including brushing, rolling, painting, dipping, spraying, production printing, encapsulation, and / or screen coating (with and / or without vacuum assistance). Coating of the material may be accomplished with a single-sided coating on one or both sides of the material, the inward-facing side of the material, although single-sided coating on the outward-facing (i.e., away from the substrate, toward the open aqueous environment) side of the material has demonstrated a significant level of effectiveness while minimizing biocide content, cost, and maintaining advantageous flexibility. Although water-based ("WB") biocidal coatings are primarily discussed in various embodiments herein, solvent-based ("SB") biocidal coatings may alternatively be used in various applications (and / or in combination with water-based paints) if desired.

[0219] In various embodiments, the use of various printing processes for the coating may have the added advantage of allowing for the incorporation of visible patterns and / or logos in and / or on the enclosure walls, which may include marketing and / or advertising the material to identify the source of the enclosure (i.e., the manufacturer of the enclosure), the identification of one or more users (i.e., a particular marina and / or boat owner / boat name), and / or the identification of the expected area and / or condition of use (i.e., "salt water flooding only" or "Jacksonville Harbor use only" or "summer use only"). If desired, various indicators may be incorporated to identify the age and / or condition of use of the enclosure, including printing a "replace by" date on the exterior of the enclosure. If desired, a visible pattern may be printed using the biocide coating itself, which may incorporate supplemental inks and / or dyes into the coating mixture, or additional logos and the like may be printed using a separate additive.

[0220] In various embodiments, the biocidal coating or paint may desirably be applied to the material in amounts ranging from 220 grams per square meter to 235 grams per square meter, although applications of less than 220 grams per square meter, including 100 grams per square meter, and applications of greater than 235 grams per square meter, including 300 grams per square meter or more, show significant potential. In various alternative embodiments, the coating mixture may include one or more biocides in various percentage weights of the mixture, including up to 10% by weight of the biocide, such as 2%, 5%, and / or 7% of the mixture, or greater amounts of the biocide, including 10%, 20%, 30%, 40%, 50%, and / or more by weight of the coating mixture, and ranges encompassing virtually any combination thereof (i.e., 2% to 10% and / or 5% to 50%, etc.). Where enclosure designs may be particularly large, it may be desirable to significantly increase the percentage of biocide in the coating mixture, which desirably reduces the total amount of coating required to protect the enclosure and / or substrate.

[0221] 29 illustrates a cross-sectional view of an exemplary permeable fabric 2900 with various pore openings 2910 and simplified passageways 2920 extending from a front surface 2930 to a rear surface 2940 of the fabric 2900. Also shown is a coating material 2950 containing a biocide or other debilitating substance, with some portions of this coating material extending into the pore openings 2910 and / or passageways 2920 of the fabric 2900 at least some distance "D" from the front surface 2930. In various embodiments, the coating material will desirably penetrate the openings / pores of the fabric and / or fabric walls of the material for some average distance "D" (i.e., penetration depth into the fabric of 3%, 5%, 10%, 15%, 20%, 25%, 50%, 75%, or more, see FIG. 29). Desirably, a coating material is applied that is often "stiffer" in the dry configuration than the fabric to which it is applied (i.e., the coating desirably will not visibly or severely "stiffen" the fabric to an undesirable degree), in a manner that allows the fabric to be bent and / or molded to some degree, and allows the fabric to be formed into a desired enclosure shape and / or wrapped around a structure and / or formed into a flexible bag and / or container (if desired). If a bag or similar enclosure (i.e., a closable shape) is provided, the coating desirably may be applied on / in the item after its manufacture, which may include coating and / or encapsulation of any seams and / or sewn / glued areas under one or more coating layers. In various embodiments, the coating penetration depth will be, on average, less than half the depth through the material.

[0222] Once coated with the biocidal coating or paint, the material and / or enclosure may be allowed to cure and / or air dry for the desired period of time (less than 2 minutes in some commercial applications, or in other embodiments up to an hour or more), or may be force dried utilizing gas, oil or electric heating elements. The material and / or enclosure may then be used as described herein.

[0223] In various embodiments, the enclosure may include a biocide attached, coated, encapsulated, incorporated, and / or "woven" into the sewing threads of the material. For example, the biocide may be incorporated into a strip containing one or more biocides at various concentrations, thus desirably preventing various plant and animal species from attaching to or establishing a presence on and / or within the enclosure. Alternatively, the enclosure may include a reservoir or other component containing the biocide in free or microencapsulated form. Microencapsulation desirably provides a mechanism by which the biocide may diffuse or be released into the environment in a time-dependent manner. Biocide-loaded microcapsules may be embedded into individual sewing threads and / or woven fabrics without the use of a reservoir or container, or the biocide may be coated onto the surfaces of the fibrous substrate elements (i.e., sewing threads) and / or the openings or "pores" between them.

[0224] Other methods of inserting and / or applying the biocide or anti-fouling agent are contemplated, such as the use of spray applications known to those skilled in the art of coatings. Additionally, the enclosure need not contain individual fibrous elements, but instead may be made of perforated and / or flexible sheets containing the biocide embedded therein and / or coated onto the material. To provide a fastening mechanism, the enclosure may include fastening elements, such as, but not limited to, hook-and-loop fasteners, such as VELCRO®, snaps, buttons, clasps, clips, buttons, adhesive strips, or zippers. If desired, the enclosure may include multiple wall structures, each wall structure attached to one or more adjacent wall structures (if any) by stitching, weaving, or the like, which may include coating and / or encapsulation of any seams and / or stitched / glued areas under one or more coating layers to form a modular enclosure. If desired, enclosure material may be added to extend beyond and / or over the enclosure fastening elements to protect the fastening elements from fouling.

[0225] In various embodiments, the enclosure desirably includes anti-bio-fouling properties attached to and / or embedded within the threads and / or fibers (i.e., various elements of the fibrous matrix) to inhibit and / or prevent bio-fouling of the enclosure. In a preferred embodiment, the anti-bio-fouling agent is a biocide coating including Econea™ (tralopyril, commercially available from Janssen Pharmaceutical NV, Belgium) and / or zinc omadine (i.e., pyrithione), although other currently available and / or future developed anti-bio-fouling agents, such as zinc, copper, or derivatives thereof, known to those skilled in the art, may be used. Additionally, anti-fouling compounds derived from microorganisms and their synthetic analogs may be utilized, with these different sources typically classified into 10 types, including fatty acids, lactones, terpenes, steroids, benzenoids, phenyl ethers, polyketides, alkaloids, nucleosides, and peptides. These compounds are sequestered from seaweed, algae, fungi, bacteria, and marine invertebrates, including larvae, sponges, worms, snails, mussels, and others. Any one or more of the above compounds and / or equivalents (and / or any future developed compounds and / or equivalents) (or various combinations thereof) can be utilized to create biofouling structures that prevent both microfouling, such as biofilm formation and bacterial attachment, and macrofouling, such as attachment of larger organisms, including barnacles or mussels, to one or more targeted species, or, if desired, can be utilized as a more "broad spectrum" foulant prevention against multiple biofouling organisms.

[0226] In one exemplary embodiment, a desirable spun polyester fiber based woven fabric may be utilized as the envelope material, with the fabric having a weight of approximately 410 grams per meter. 2 (See Table 8) [Table 16]

[0227] Table 9 shows several alternative fabric specifications that may be utilized as the enclosure wall material with various levels of utility. [Table 17]

[0228] For various structural or enclosure embodiments, the target weight add-on of paint / coating is currently approximately 5 grams / meter. 2 ~500 grams / meter 2 , about 50 grams / meter 2 ~480 grams / meter 2 , about 100 grams / meter 2 ~300 grams / meter 2 , about 120 grams / meter 2 ~280 grams / meter 2 , approximately 224 grams per meter 2 27A and 27B illustrate various additional exemplary embodiments including various coating weights of the fabric for use with various enclosure designs.

[0229] In various embodiments where the addition of a biocide or other coating may be desired, it should be understood that in some embodiments the coating may be applied to the enclosure after it is fully assembled and / or constructed, while in other embodiments the coating may be applied to some or all of the enclosure's components prior to assembly and / or construction. In still other embodiments, some portions of the enclosure may be pre-coated and / or pre-treated, while other portions may be coated after assembly. Additionally, where process and / or treatment steps during the manufacture and / or assembly of the enclosure may involve techniques that may adversely affect the quality and / or performance of the biocide or other coating properties, it may be desirable to perform those process and / or treatment steps on the enclosure and / or enclosure components prior to application of the coating. For example, where a heat-sensitive biocide and / or coating may be desired, material processing techniques involving high temperatures may be employed to fabricate and / or process the fabric and / or enclosure walls prior to application of the biocide coating (i.e., to reduce the chance of heat-related degradation of the biocide and / or coating).

[0230] In various embodiments, coating materials or other additives (including biocidal coatings or other materials) may be applied and / or incorporated into the enclosure fabric, potentially resulting in an altered level of permeability that may transform a material that may be less suitable for protecting a substrate from biofouling into one that is more desirable for protecting a substrate from biofouling once in the coated condition. For example, as described herein, an uncoated polyester fabric experimentally demonstrated relatively high permeability to liquids (i.e., 150 mL of liquid passed through the test fabric in less than 50 seconds) that may be less desirable for forming an enclosure to protect a substrate from biofouling. However, when properly coated to a desired level with a biocidal coating, the permeability of the coated fabric may be substantially reduced to a highly desirable level, such as a moderate permeability level (i.e., 100 mL of liquid passed through the test fabric in 50-80 seconds) and / or a very low permeability level (i.e., little or no liquid passed through the test fabric). In this manner, the planned permeability level may optionally be "dialed" or tailored for each selected fabric, if desired.

[0231] During prolonged immersion testing in an aqueous environment, one embodiment of an enclosure incorporating a polyester coated fabric exhibited no macrofouling and / or very minimal macrofouling coating. Further, one example of the polyester fabric was more permeable during the immersion period, while another example became less permeable during the immersion period.

[0232] FIG. 16A illustrates another exemplary embodiment of an uncoated 23×23 woven polyester fabric that experimentally demonstrates a relatively low permeability to liquids (i.e., 100 mL of liquid passed through the test fabric in approximately 396 seconds) that, depending on local conditions, may be on the lower end of a desired permeability range for forming an enclosure to protect a substrate from biofouling as described herein. When coated (see FIG. 16B), these materials became essentially impermeable before submersion, but more permeable after submersion. As noted above, the desired permeability level can be “dialed” or tailored for each selected fabric, if desired. In various embodiments, the permeability of a given fabric and / or enclosure component may change or differ in wet or dry conditions, if desired.

[0233] During prolonged immersion testing in an aqueous environment, the uncoated 23x23 polyester and the coated polyester fabrics were all free of macrofouling on the enclosure and / or substrate. Furthermore, each of these materials underwent a significant increase in permeability during immersion, with the 23x23 uncoated polyester fabric allowing the passage of 150 mL of liquid in 120 seconds, while the first 23x23 coated polyester fabric allowed 150 mL of liquid in 160 seconds and the second 23x23 coated polyester allowed 150 mL of liquid in 180 seconds.

[0234] In another alternative embodiment, Figures 17A-17C illustrate a natural material, burlap, that is uncoated (Figure 17A), coated with a solvent-based biocidal coating (Figure 17B), and coated with a water-based biocidal coating (Figure 17C). During permeability testing, the uncoated burlap demonstrated a permeability of 50.99 ml / sec / cm2, while the coated burlap had permeabilities of 52.32 ml / sec / cm2 and 38.23 ml / sec / cm2 for the solvent-based and water-based biocidal coatings, respectively. After 32 days of submersion in salt water, the permeability of both coated fabrics increased significantly to 85.23 ml / sec / cm2 and 87.28 ml / sec / cm2, while the uncoated burlap decreased in permeability to 20.42 ml / sec / cm2. Fouling observations showed that the uncoated burlap experienced very minimal fouling and the coated burlap experienced virtually no macrofouling.

[0235] Additionally, in another alternative embodiment, uncoated 1 / 64 polyester fabrics were coated with a solvent-based biocidal coating and alternatively with a water-based biocidal coating. During permeability testing, the uncoated 1 / 64 polyester fabric demonstrated a permeability of 26.82 ml / sec / cm2, while the coated 1 / 64 polyester fabrics had permeabilities of 44.49 ml / sec / cm2 and 29.25 ml / sec / cm2 for the solvent-based and water-based biocidal coatings, respectively. After 32 days of immersion in salt water, the permeabilities of all 1 / 64 polyester fabrics were significantly reduced to 10.99 ml / sec / cm2, 13.78 ml / sec / cm2, and 13.31 ml / sec / cm2, respectively. Fouling observations showed that the uncoated 1 / 16 polyester fabric was subject to some degree of fouling, whereas the coated 1 / 64 polyester fabric was subject to virtually no macrofouling.

[0236] A variety of different fabrics were manufactured, coated, and utilized in the construction and testing of biofouling prevention enclosures. In a first embodiment (shown in FIG. 18A with a scale of 1000 μm), a textured polyester fabric is coated with a biocide coating on a first substrate, with a substantial amount of the coating penetrating completely through the fabric to the opposing second surface (some areas of the coating on the second surface are thinner than others). FIG. 18B illustrates the coated fabric at a scale of 1000 μm. On average, the coated fabric has 523.54 (±2.33) pores / inch. 2 with approximately less than 5 percent of the pores being blocked (on average).

[0237] Figure 18C illustrates another preferred embodiment of a 100% spun polyester fabric, and Figure 18D illustrates this fabric coated with a biocidal coating. During testing, the uncoated 100% polyester fabric had a biocidal absorption rate of 10.17 ml / sec / cm of fabric. 2 The coated polycloth demonstrated a permeability of 0.32 ml / sec / cm 2 and 1.08 ml / sec / cm 2 After 23 days of submersion in water, the permeability of both coated fabrics did not change significantly, with the uncoated poly fabric experiencing very minimal fouling and the coated poly fabric experiencing virtually no macrofouling. However, in various other embodiments, other techniques for preparing spun polyester yarns, such as core-spun staple fibers around a continuous core, open-end spinning, ring spinning, and / or air-jet spinning, are expected to produce similarly favorable results.

[0238] In another embodiment (uncoated fabric shown in FIG. 18E with a scale of 500 μm), a spun polyester fabric is then coated on a first surface with a biocide coating, with a substantial amount of this coating partially penetrating through the fibers and / or pores of the fabric (in some embodiments, penetrating up to 50% or more through the fabric). FIG. 18F shows the opposing uncoated side of the fabric at 1000 μm, which also demonstrates the significant pore size reduction that can be achieved using this coating technique, if desired. On average, this coated fabric has 493 (±3.53) pores / inch. 2 with approximately 7-10 percent of the pores being completely blocked by the coating material (on average).

[0239] Experimentally, all of these fabric embodiments demonstrated desirable levels of permeability, which may be attributed to the large number of small pores, smaller size fibers, and / or various combinations thereof. Various coating methods were highly effective at coating and penetrating the fabric to the desired levels, producing highly effective materials for incorporation into protective enclosures.

[0240] Figure 19 and Table 3 show various fabrics potentially suitable for use in various embodiments of the present invention, along with exemplary permeabilities of these fabrics in their uncoated and coated states. For example, in Port Canaveral Harbor (Port Canaveral, Florida, USA), the permeability is 0.5 ml / sec / cm 2 ~25ml / sec / cm 2 ~50ml / sec / cm 2 ~75ml / sec / cm 2 ~100ml / sec / cm 2 , or about 0.1 ml / sec / cm 2 ~Approx. 100ml / sec / cm 2 ,cm 2 , or about 1 ml / sec / cm 2 ~Approx. 75ml / sec / cm 2, or about 1 ml / sec / cm 2 ~Approx. 10ml / sec / cm 2 , or about 1 ml / sec / cm 2 ~Approx. 5ml / sec / cm 2 , or about 5 ml / sec / cm 2 ~Approx. 10ml / sec / cm 2 , or about 10 ml / sec / cm 2 ~About 20ml / sec / cm 2 , or about 10 ml / sec / cm 2 ~Approx. 25ml / sec / cm 2 , or about 10 ml / sec / cm 2 ~Approx. 50ml / sec / cm 2 , or about 20 ml / sec / cm 2 ~Approx. 70ml / sec / cm 2 , or about 10 ml / sec / cm 2 ~About 40ml / sec / cm 2 , or about 20 ml / sec / cm 2 ~Approx. 60ml / sec / cm 2 , or about 75 ml / sec / cm 2 ~Approx. 100ml / sec / cm 2 , or about 60 ml / sec / cm 2 ~Approx. 100ml / sec / cm 2 , or about 10 ml / sec / cm 2 ~Approx. 30ml / sec / cm 2 It has been experimentally determined that a permeability range of 0.5 ml / sec / cm is sufficient (depending on local conditions) to prevent significant amounts of fouling from occurring on and / or within the enclosure and / or on the protected substrate, while still allowing sufficient water flow to inhibit and / or prevent anoxia within the enclosure. 2 Fabrics having the following permeabilities may be suitable for various enclosure embodiments, where occasional periods of low oxygen conditions may be acceptable and / or desirable. Permeabilities lower than these ranges may lead to anoxic conditions during periods of low water movement in some areas, which may be less desirable and / or undesirable in various embodiments. In another exemplary embodiment, a permeability of at least 0.32 ml / sec / cm 2, and up to 10.17 ml / sec / cm 2 It has been determined that a permeability range of at least 1.5 ml / sec / cm is the optimum range of desirable permeability characteristics and / or the desired range of expected permeability changes over the life of the enclosure. In other embodiments, 2 , and up to 8.0 ml / sec / cm 2 may be desirable (as well as any combination of the various ranges disclosed herein). Often, the incidence of fouling intrusion and / or rate of fouling growth in a given area and / or body of water for a particular fouling organism may be highly dependent on a multiplicity of interrelated factors, as well as the local and / or seasonal conditions of the intended area of ​​use (and, among other things, the substrate intended to be protected), and the acceptable range of permeability of a given fabric for a given enclosure design may vary widely, and thus a fabric permeability that may be optimal and / or suitable for one enclosure design and / or location may be less optimal and / or suitable for another enclosure design and / or location. In FIG. 19, the "more" and "less" fouling arrows on the graph relate to the fouling observed on the protected substrate, and these permeability numbers and ranges therein should be interpreted as general trends in permeability and / or the ability of a given fabric to provide anti-fouling protection while avoiding long periods of anoxic conditions in a given body of water, but should not be interpreted as precluding the use of a given fabric in other enclosure designs and / or water conditions.

[0241] In various embodiments, the permeability of the enclosure material may desirably be maintained within a desired permeability range over its in situ service life (or, if desired, until a desired biofilm layer is established), such that any potential increases in the permeability of the material due to changes in the enclosure structure and / or materials (by way of example) will desirably approximate any expected decreases in the permeability of the material due to clogging of pores with organic and / or inorganic debris (including any biofouling of the material and / or its pores that may occur). This balance will desirably maintain the integrity and / or function of the enclosure and the properties of the differentiated environment over extended periods of time, providing significant protection to the enclosure and / or protected substrate.

[0242] In various embodiments, the enclosure walls may incorporate various materials that undergo permeability changes during immersion testing in an aqueous environment over an extended period of time. For example, uncoated synthetic materials may generally become less permeable over time (which may be due to gradual fouling of the fabric once positioned around a substrate), while some materials coated with biocidal coatings may undergo various permeability changes, including some embodiments that become less permeable over time. Additionally, the natural test fiber (burlap) in the uncoated state became more permeable, while the biocide-coated burlap became less permeable over time. In various embodiments, variations in coating parameters (i.e., coating addition / thickness, application method, vacuum application to maintain and / or increase pore size, drying parameters, etc.) and various fiber parameters (i.e., construction, material, initial permeability, with or without constraints during drying, with or without heat setting, etc.) may allow for a wide range of desired permeability characteristics and expected permeability changes over the life of a given enclosure design. Thus, when deployed in an aqueous environment, it is possible to influence (and / or control) whether permeability increases or decreases over time over a period of time and the associated correlation with the product life cycle.

[0243] In various embodiments, the enclosure may desirably inhibit biofouling on a substrate at least partially immersed in an aquatic environment, the enclosure comprises a material that is or becomes water permeable during use, the enclosure is adapted to receive the substrate and form a distinct aquatic environment extending from a surface of the substrate to at least an interior / exterior surface of the structure, and the structure or portions thereof have a water permeability of about 100 milliliters / second of water per square centimeter of substrate, about 100 milliliters / minute of water per square centimeter of substrate, or a value therebetween, or greater / lesser, upon or after positioning the structure around the substrate.

[0244] In various embodiments, the water permeability of the structure may be achieved by forming the structure to allow water to permeate through it, such as by weaving the fibers to have the desired permeability and / or optionally coating the fibers with a biocide coating (or a non-biocide-containing coating) that provides the fibers with the desired permeability. In some embodiments, the structure may be designed to become water permeable over time as it is used. For example, other water permeable structures may have a coating that initially makes it substantially impermeable, but as the coating dissolves, erodes, or dissolves, the underlying permeability increases and / or becomes useful.

[0245] FIG. 20 and Table 10 (below) show one exemplary test of the water permeability of an enclosure incorporating a permeable fabric wall. In this embodiment, an initial high concentration of rhodamine was created within the enclosure in an aqueous environment, and then the rhodamine concentration was measured over time to determine how the concentration of this marker decreased as water exchange occurred inside and outside the permeable wall of the enclosure. Testing revealed that the residence time of rhodamine within this enclosure of that size and wall permeability was approximately 4 hours and 10 minutes, with a half-life of 3 hours, and a water permeability of approximately 0.0027 ml / cm. 2 / sec. [Table 18]

[0246] The rhodamine dye test was utilized as an analog to determine the water exchange rates within the various test enclosures. For example, a YSI Total Algae Sensor (TAL) was placed into a fully bagged stern simulant. Rhodamine at a concentration of 0.9 mg / L was added to the stern simulant. When the data returned to the background concentration of dye in the bag, the YSI was placed in open water for two days to obtain open water readings to compare to undosed bag levels. Residence times, half-lives, and flow rates were calculated from the rhodamine data. Residence times were calculated as 37% of the initial concentration of rhodamine dye. Half-life was calculated as 69.3% of residence time (using these calculations found in the literature). Flow rates were calculated by taking twice the volume (accounting for one volume in and one volume out) and dividing it by the residence time and surface area. Rhodamine concentrations in mg / L were graphed after subtracting background dye to get a better idea of ​​the dilution rate. Test results indicate that it took approximately 26 hours for the pigment concentration of the stern imitation to stabilize and return to natural levels. Based on a residence time of 4 hours 10 minutes and a flow rate of 0.0027 mL / cm 2 / sec.

[0247] In various embodiments, it may be highly desirable for the enclosure or a portion thereof to initially have high permeability, with subsequent reduction in permeability occurring after the enclosure is placed around the substrate to be protected. For example, an enclosure with very low permeability may maintain positive buoyancy after placement in an aqueous medium, which may make it difficult, if not impossible, to place the enclosure around a submerged and / or partially submerged substrate. In contrast, an enclosure incorporating more permeable elements may "sink" more easily upon deployment around a substrate. Such an enclosure may include a lower portion that is highly permeable (to allow for water inflow and rapid filling of the enclosure), with other enclosure elements that are of higher or lower permeability. Once deployed around the substrate as needed, the more permeable elements may change permeability (i.e., higher or lower permeability) or maintain the same permeability as needed.

[0248] In various embodiments, when an enclosure as described herein is utilized, the biological colonization sequence on the substrate can be interrupted (disrupted, altered, etc.) to reduce and / or minimize settlement, recruitment, and eventual macrofouling of the substrate. Once positioned around or inside (when protecting the substrate's interior surface) the permeable protective fabric wall of the enclosure can desirably filter and / or impede the passage of various micro- and / or macro-organisms into the enclosure, and the optional biocidal coating can, in some embodiments, prevent fouling of the enclosure and / or injure and / or harm some and / or all of the organisms as they contact and / or pass through the fabric. If desired, the biocidal coating can undergo significant biocidal leaching upon initial placement around the substrate to establish an initial higher "kill level" that impacts the fouling organisms, which can be significantly reduced over a period of time as the chemical composition of the water within the enclosure changes to create the desired differentiated environment, thus protecting the substrate from further fouling.

[0249] In one exemplary embodiment, testing of microscopic plankton passing through the biocide-coated permeable fabric membrane of the enclosure indicated that some organisms were likely to survive and be viable after passage, while some other organisms were likely to be harmed and / or injured during passage. This observation of live organisms within the enclosure was reinforced by testing of differentiated water within the enclosure, which showed that a significant percentage of microorganisms within the enclosure that use appendages (such as bivalve larvae and tunicates with velocities of 1-10+ cm / sec) appeared to remain viable within the biocide-coated enclosure, along with many viable microorganisms that use cilia (such as bivalve veliger larvae and tubeworms with velocities in the range of 0.5-2 mm / sec). However, even while live fouling organisms were ...

Claims

1. 1. A device for reducing biofouling on a substrate at least partially submerged in an aqueous environment, the device comprising: a structure that is or becomes water permeable during use, the structure defining an open end adapted to receive through said substrate, the structure defining an enclosure having one or more walls that remain spaced apart from a surface of said substrate in a non-sealed arrangement by said open end, the structure comprising at least one of a mesh, a lattice, a fenestration, and a hole that allows fluid to flow therethrough, the structure comprising a three dimensional flexible material selected from the group consisting of natural and synthetic fabrics, natural and synthetic membranes, natural and synthetic sheets, and fabrics, membranes, films, and sheets made from combinations of natural and synthetic materials; the structure separates the aqueous environment into a localized aqueous environment and an open aqueous environment, the localized aqueous environment extending from a surface of the substrate to at least an interior surface of the structure; A device, wherein the structure regulates dissolved oxygen content from the open aqueous environment into the local aqueous environment.

2. 2. The device of claim 1, wherein the local aqueous environment comprises a first dissolved oxygen content and the open aqueous environment comprises a second dissolved oxygen content, the first dissolved oxygen content being different from the second dissolved oxygen content.

3. 2. The device of claim 1, wherein the localized aqueous environment comprises a first dissolved oxygen content and the open aqueous environment comprises a second dissolved oxygen content, and wherein, on average, the first dissolved oxygen content is less than the second dissolved oxygen content when measured over a period of at least 24 hours.

4. 2. The device of claim 1, wherein the localized aqueous environment comprises a first dissolved oxygen content and the open aqueous environment comprises a second dissolved oxygen content, the first dissolved oxygen content comprises a first rate of change over a period of time and the second dissolved oxygen content comprises a second rate of change over the period of time, the first rate of change being the same as, faster than, or higher than the second rate of change.

5. 2. The device of claim 1, wherein the localized aqueous environment comprises a first dissolved oxygen content and the open aqueous environment comprises a second dissolved oxygen content, the first dissolved oxygen content comprises a first rate of change over a period of time and the second dissolved oxygen content comprises a second rate of change over the period of time, the first rate of change being slower than or less than the second rate of change.

6. 2. The device of claim 1, wherein the localized aqueous environment has a first dissolved oxygen content proximate the interior surface of the structure and a second dissolved oxygen content proximate an exterior wall of the substrate, the first dissolved oxygen content being different from the second dissolved oxygen content.

7. The device of claim 6 , wherein the second dissolved oxygen content is less than the first dissolved oxygen content.

8. 3. The device of claim 2, wherein there is at least a 5% difference between the first dissolved oxygen content and the second dissolved oxygen content when measured after the structure is at least partially immersed in the aqueous environment for at least two days.

9. 10. The device of claim 1, wherein the structure provides an average water exchange between the local aqueous environment and the open aqueous environment of between 0.1% and 500% of the volume of water in the local aqueous environment per hour.

10. 10. The device of claim 1, wherein the structure includes a water permeable surface having a water permeability of about 100 milliliters per second per square centimeter of the structure or less.

11. The device of claim 1 , wherein a chemical composition of a first water in the localized aqueous environment is different from a chemical composition of a second water in the open aqueous environment.

12. 3. The device of claim 2, wherein on average, the first dissolved oxygen content is less than the second dissolved oxygen content during the day.

13. 3. The device of claim 2, wherein on average, the first dissolved oxygen content lags behind the second dissolved oxygen content when measured over a period of at least 24 hours.

14. 3. The device of claim 2, wherein the first continuous dissolved oxygen content reading is more buffered compared to the second continuous dissolved oxygen content reading when measured over a period of at least 24 hours.

15. The device of claim 1 , wherein the structure comprises a biocide.

16. 1. A method for reducing biofouling on a substrate at least partially submerged in an aqueous environment, the method comprising: using a structure that is or becomes water permeable during use, the structure defining an open end adapted to receive through said substrate, the structure defining an enclosure having one or more walls that remain spaced from a surface of said substrate in a non-sealed arrangement by said open end, the structure comprising at least one of a mesh, a lattice, a fenestration, and a hole that allows fluid to flow through, the structure separating an aqueous environment into a localized aqueous environment and an open aqueous environment, the localized aqueous environment extending from a surface of said substrate to at least an interior surface of said structure, the structure comprising a three dimensional flexible material selected from the group consisting of natural and synthetic fabrics, natural and synthetic membranes, natural and synthetic sheets, and fabrics, membranes, films, and sheets made from combinations of natural and synthetic materials; Dispensing a substance that reduces a dissolved oxygen content in the localized aqueous environment by at least 10% relative to a saturated dissolved oxygen content; A method comprising:

17. The method of claim 16 , wherein the substance comprises nitrogen gas.

18. 20. The method of claim 17, wherein dispensing the substance comprises sparging the localized aqueous environment with nitrogen gas.

19. The method of claim 16 , wherein the material comprises an iron filler.

20. 17. The method of claim 16, wherein the structure provides an average water exchange between the local aqueous environment and the open aqueous environment of between 0.1% and 500% of the volume of water in the local aqueous environment per hour.

21. 17. The method of claim 16, wherein the structure comprises a water permeable surface having a water permeability of 100 milliliters per second per square centimeter of the structure or less.

22. 17. The method of claim 16, wherein the structure maintains an average dissolved oxygen content of the localized aqueous environment of at least 10% or greater when measured over a period of at least 24 hours.

23. 17. The method of claim 16, wherein a chemical composition of a first water in the localized aqueous environment is different from a chemical composition of a second water in the open aqueous environment.

24. The method of claim 16 , wherein the structure comprises a biocide.

25. 3. The device of claim 2, wherein the structure regulates the dissolved oxygen content such that the first dissolved oxygen content lags behind a change in the second dissolved oxygen content at a reduced level.

26. 12. The device of claim 11, wherein the chemical composition of the first water differs from the chemical composition of the second water by having at least one difference in a water chemical composition characteristic, the water chemical composition characteristic being one of dissolved oxygen, pH, total dissolved nitrogen, ammonium, nitrate, orthophosphate, total dissolved phosphate, alkalinity, silica, salinity, and chlorophyll.

27. 27. The device of claim 26, wherein the at least one difference in the water chemical composition characteristic is at least a 10% difference when measured after the structure is at least partially immersed in the aqueous environment for at least 2 days.

28. 13. The device of claim 1, further comprising at least one floating boom attached to said structure, said at least one floating boom configured to float above a water surface of said aqueous environment, enabling said structure to maintain a depth within said aqueous environment.

29. The device of claim 1 , wherein the structure is flexible.

30. 2. The device of claim 1, wherein the structure defines a first side including the inner surface and an opposing second side, and when the structure at least partially surrounds the substrate in the aqueous environment such that the first side of the structure faces the surface, the structure allows fluid exchange through the structure to the substrate while preventing or limiting biofouling on the substrate such that a first chemical composition of the aqueous environment on the first side of the structure is different from a second chemical composition of the aqueous environment on the second side of the structure.

31. A roll of material used to form the device of claim 1 , said material comprising said structure.

32. The method of claim 16 , wherein the surface area of ​​the structure is at least as great as the surface area of ​​the substrate.

33. The method of claim 16 , wherein the surface area of ​​the structure is less than the surface area of ​​the substrate.

34. 31. The device of claim 30, wherein the second chemical composition is measured in the open aqueous environment 12 inches away from the second side of the structure.

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