Durable biofouling protection

Abstract

To provide materials, devices, methods, and / or systems for use in protecting against fouling in an aquatic environment.SOLUTION: A material includes a water-permeable structure, the structure defining an enclosure by an open end adapted to pass through and receive a substrate, the structure having at least one of a mesh, a grid, a window formation, and a hole, the structure being a natural and synthetic fabric, a natural and synthetic membrane, a natural and synthetic sheet including a three-dimensional flexible material and defining a first side and a second side, in which the structure at least partially surrounds the surface in the aqueous environment such that the first side faces the surface and the first chemical composition of the aqueous environment between the first side and the second side is different from the second chemical composition of the aqueous environment outside the second side to allow fluid exchange through the structure to the surface while preventing or limiting biofouling on the surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Provisional Patent Application No. 62 / 754,574, entitled "DURABLE BIOFOULING PROTECTION," filed on November 1, 2018, and U.S. Patent Application No. 62 / 817,873, entitled "BIOFOULING PROTECTIVE ENCLOSURES," filed on March 13, 2019, the disclosures of which are hereby incorporated by reference in their entireties.

[0002] The present invention relates to improved devices, systems, and methods for use in protecting items and / or structures that are exposed to an aqueous environment, immersed in an aquatic environment, and / or partially immersed, from contamination and / or fouling caused by the intrusion and / or colonization by certain types and / or classes of biological organisms. More specifically, improved methods, devices, and / or systems for protecting structures and / or substrates from micro - and / or macro - fouling during long - term exposure to an aquatic environment are disclosed.

Background Art

[0003] The growth and attachment of various marine organisms to structures in the aquatic environment, known as biofouling, is a significant problem for many industries, including both recreational and commercial boating and shipping industries, oil and gas industries, power plants, water treatment plants, water management and control, irrigation industries, manufacturing, scientific research, military (including engineering corps), and fisheries. Most surfaces associated with boat hulls, underwater cables, chains, and piles, oil drilling platforms, buoys, and fishing nets, etc., that are exposed to coastal water, harbor water, or ocean water (and their freshwater counterparts) will ultimately be colonized by animal species such as barnacles, mussels (as well as oysters and other bivalves), bryozoans, hydroids, tube worms, tunicates and / or other urochordates, as well as various plant species. Biofouling results from the interaction between these various plant and / or animal species and the nature of the substrate to which they ultimately attach, which leads to the formation of adhesives that firmly bond the biofouling organisms to the substrate, which in turn leads to biofouling. Although seemingly simple, the biofouling process is a very complex network of interactions affected by countless microorganisms, macroorganisms, and the constantly changing characteristics of the aquatic environment.

[0004] The economic impact of biofouling is of greatest concern to many industries. Heavy biofouling of ships can result in corrosion of various surfaces exposed to the aquatic environment, a significant reduction in the operational efficiency of the ship, and often, the ultimate deterioration of parts of the ship. The accumulation of macroorganisms also causes an increase in the roughness of the ship's surface, which causes the ship to experience greater frictional resistance, a decrease in speed and maneuverability, and an increase in drag, resulting in increased fuel consumption. These increased costs are also experienced by commercial and recreational boaters alike due to the attachment of barnacles and other animals to propellers, drive system components, intakes, 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 stress, and strain experienced by the object and / or support structure, which can lead to premature failure and / or sinking of the contaminated object. For example, a navigation buoy or pier support with a surface containing a large amount of biofouling can experience increased stress loads resulting from the increased weight and may even collapse or sink under an excessive amount of macrofouling. This increased stress often reduces the lifespan of the structure and results in the need for continuous cleaning and / or replacement. Similarly, underwater sensors (including cable-type sensors and / or free-floating sensors) often fail and / or malfunction relatively quickly (often within less than 30 days) due to the intrusion and / or colonization of marine organisms.

[0006] Biofouling also causes significant ecological problems by distributing plant and animal species into foreign environments when the plant and animal species "hitchhike" on contaminated objects, and considerable legislative and financial resources have been allocated to combat the commercial and ecological impacts of biofouling.

[0007] In attempts to halt and / or reduce the accumulation of biofouling, various methods have been used. One method that is more common, particularly in the boat and shipping industries, is the removal of biofouling by scraping. However, scraping is labor-intensive, can damage the contaminated surface, and raises environmental concerns as scraping can increase the spread of invasive species and result in negative environmental impacts on the local fauna. Therefore, there is a need for devices that eliminate or reduce the amount of biofouling on surfaces exposed to an aquatic environment.

[0008] One strategy for protecting objects in contact with water and preventing aquatic biofouling involves the use of physical coatings. These coatings preferably act as protective devices by shielding or separating the structure from the water. For example, U.S. Patent No. 3,220,374 discloses a marine protection device. This invention is directed to unique means and methods for protecting marine equipment from the corrosive effects of water and / or marine growth 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. This device protects the outdrive of an inboard / outboard motor from marine growth when the boat is not in use. Bags are disposed around the outdrive unit for easy attachment to the transom of the boat in a manner that provides a watertight seal between the back and the transom and around the outdrive unit.

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

[0011] U.S. Patent No. 5,072,683 discloses a drainable protective boat motor bag device that includes a boot defining a bag that conforms to a propeller and a stem of an outdrive of a motor mounted on the stern of a boat. The bag includes a channel extending from an opening to a closed end of the bag for receiving an open-ended hose once the bag is positioned on the stem so that the hose can be inserted for pumping residue from such bag. A drawstring can be incorporated around the mouth of the bag to tie the mouth of the bag to the stem, and if desired, a separate protective sack can be included to cover the propeller blades and protect the propeller blades from being directly exposed to the bag itself.

[0012] U.S. Patent No. 5,315,949 discloses a device for protectively covering a motor post of a boat. The cover includes an adjustable collar, a flexible opaque bag, and an adjustable collar drawline. The bag has an open upper end attached to the collar. The closed lower end of the bag is on the opposite side and has a weight attached thereto. The adjustable collar drawline of the collar is configured such that with the bag positioned over an exposed portion, the open end of the bag can be closed around the exposed portion by pulling the adjustable collar drawline. The collar includes a locking slot for locking the adjustable collar drawline in a fixed position around the exposed portion. An operating handle is removably attached to the collar to facilitate placement and removal of the cover relative to the exposed portion. According to the cover in a fixed position on the exposed portion, water and light are preferably prevented from entering inside the bag, thereby preferably preventing aquatic organisms such as filter-feeding organisms and plants from breeding inside the cover.

[0013] U.S. Patent 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 fixed to the flexible sleeve, and the ends of the cover are releasably fixed around the propeller. The buoyant enclosure is positioned adjacent to the propeller and extends above the water level when the propeller is positioned below the water level. The buoyant enclosure also functions to protect a swimmer from direct contact with the propeller when swimming near the boat. The protective propeller cover device further functions to protect the propeller during transportation or storage. The protective propeller cover device further functions as an anchor cover when the boat is in motion. The protective propeller cover device further functions as an emergency flotation device.

[0014] U.S. Patent No. 6,609,938 discloses a propeller protector ripper for use on inboard and outboard motors of a boat out of the water while at anchor, adrift, aground, docking, in storage, or in transit. The propeller protector ripper protects the propeller from elements that cause pitching and damage to the propeller and minimizes propeller-related damage. The propeller protector ripper also provides a gauge for projecting the distance of the propeller of a towed boat from a following vehicle.

[0015] U.S. Patent Application Publication No. 2008 / 0020657 discloses a device for protecting an outdrive of a marine vessel. The device includes a positioning member adapted to be attached to the underside of a marine vessel's transom and a shroud engageable with the positioning member to provide an enclosure around the outdrive. The shroud is buoyant and can be floated to slidably engage the positioning member. The shroud preferably has an opening that closes when the shroud engages the transom of the marine vessel to prevent water from entering the interior of the shroud. Connecting means and locking means are provided to releasably connect 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. U.S. 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 a 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 positioned on the shell so as to preferably reduce vortex-induced vibration and minimize drag on the marine element. One or more antifouling agents may be disposed on, in, or around at least a portion of the shell, fins, or combinations thereof.

[0017] U.S. Patent No. 7,390,560 discloses a coating system for fouling removal from a substrate. The system includes a hull that is submerged in water or seawater for an extended period of time. The system comprises a conductive layer, an antifouling layer, and 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 antifouling 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 antifouling layer when the conductive layer is exposed to pulses of electrical, acoustic, or microwave energy or combinations thereof.

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

[0019] When attempting to directly shield and / or isolate these objects from the effects of biofouling, a wide variety of surface coatings, paints, and / or other materials for application to the outer surface of underwater objects are also known in the art. Many of these coatings and / or other materials rely on biocidal additives and / or metal additives (i.e., copper), which desirably leach into the surrounding aqueous environment over time and interfere with biofouling organisms in various ways. For example, divalent Cu 2It interferes with enzymes on the cell membrane and prevents cell division of various biofouling organisms. However, tributyltin (TBT) biocides (which are currently prohibited from use as marine biocides in many developed countries) and / or other organotin compounds kill many marine organisms or retard their growth, and many of these substances can also function as endocrine disruptors. However, the process of preparing the underwater surface(s) of an object and then applying and / or bonding such a paint / coating directly to such surface(s) is often a costly and time-consuming process (requiring even the removal of the object from the aqueous environment and / or even the dry docking of a ship), and all of these coatings have a limited duration, typically losing their effectiveness over time and often having a harmful (and undesirable) impact on the organisms in the surrounding aqueous environment. Similar difficulties also exist for systems that rely on ablation and / or surface properties such as hydrophobic, superhydrophobic, and / or non-adhesive (i.e., non-sticking and / or supercilious) surfaces.

[0020] More recently, systems that rely on the release or generation of active caustic agents such as chlorine released into an aqueous environment (i.e., electrochlorination systems that produce hypochlorite compounds from seawater) have been used, particularly in cooling and / or filtered water systems for large-scale industrial facilities, in an attempt to reduce and / or prevent biofouling. In addition to the high cost of purchasing and / or operating such systems, such corrosive substances (which can be powerful oxidants in the case of chlorine) can cause harmful effects far beyond the intended use environment (i.e., once released, they can damage organisms in the surrounding aquatic environment), and many of these substances can also promote the corrosion and / or decomposition of the item itself or related system components that they are intended to protect.

[0021] Various attempts have also been made in the art to completely isolate an object from biofouling elements in an aqueous environment, such as by forming 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 being protected) typically becomes stagnant and / or anaerobic very rapidly, leading to high levels of anaerobic corrosion of various materials, particularly high levels of corrosion in an anaerobic sulfate-rich environment such as anaerobic seawater. SUMMARY OF THE INVENTION

[0022] The various inventions disclosed herein include an understanding of the need for improved methods, devices, and / or systems for protecting structures and / or substrates from micro- and / or macrofouling against long-term exposure to an aquatic environment, including situations where a completely sealed "enclosure" or other type of outer coating may be impractical, impossible, and / or inconvenient to continuously utilize around an exposed substrate structure. This includes situations where the substrate or other object is moving through an aqueous environment or providing some form of propulsive force (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 being distilled for fresh water), and / or where a sensor or other device is being utilized to record and / or sample the surrounding aqueous environment.

[0023] The various inventions disclosed herein further include the understanding that a completely enclosed enclosure that completely isolates a 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 can be subject to corrosion or other effects from anaerobic, acidic and / or other conditions that can occur within and / or in proximity to the substrate (as well as other conditions related to such ambient environments, such as the action of microbiologically induced corrosion). Thus, optimal protection of the substrate can be provided by an enclosure that at least partially (but not completely) separates the substrate from various characteristics and / or aspects of the surrounding aqueous environment.

[0024] In various embodiments, a biofouling prevention “enclosure” or “barrier” can be positioned around, against, and / or otherwise near a substrate or other object to filter, sort, 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 No. 62 / 754,574, entitled “DURABLE BIOFOULING PROTECTION,” filed Nov. 1, 2018, and co-pending U.S. Patent Application No. 62 / 817,873, entitled “BIOFOULING PROTECTIVE ENCLOSURES,” filed Mar. 13, 2019, the disclosures of which are incorporated herein by reference in their entirety. More specifically, various embodiments of the enclosure preferably form a “bounded,” enclosed, and / or distinct aqueous environment in the immediate vicinity of the substrate, which filters or blocks the substrate from direct biofouling by some types of microbes and / or media and, in at least some instances, can function to promote the formation of a relatively durable surface, coating, or layer on the substrate and / or the enclosure wall, which, in the absence of the enclosure, can potentially inhibit, impede, avoid, and / or prevent subsequent colonization, mobilization, and / or colony formation of the substrate surface by undesirable types of biofouling organisms over time. In many instances, window formation in the enclosure wall allows 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 also change the chemical composition and / or turbidity of the water of the liquid contained within the enclosure, leading to different levels of clay, sediment, finely divided inorganic and organic matter, algae, soluble colored organic compounds, chemicals and compounds, plankton, and / or other microscopic organisms suspended in the distinct liquid as compared to that of the surrounding open aqueous environment, and these levels can contribute in various ways to fouling and / or corrosion (or lack thereof) of the substrate contained within the enclosure.

[0025] In various embodiments, the enclosures described herein are protected such that they are disadvantageous or become disadvantageous to the settlement and / or recruitment of aquatic organisms that contribute to various types of biofouling, adjacent to the substrate or surface that is immersed and / or partially immersed and that will be protected, and act to create an "enclosed", "localized", "contained", and / or "differentiated" aquatic environment (including surfaces that create a "negative" settlement cue for one or more types of biofouling organisms, and surfaces that may lack and / or exhibit a reduced level of a "positive" settlement cue). The enclosure(s) of various embodiments also preferably filter, reduce, and / or prevent many marine organisms that contribute to biofouling from entering the enclosure and / or contacting the immersed and / or partially immersed surface of the substrate.

[0026] In various embodiments, the enclosure may include a permeable formable substrate, a fibrous substrate, and / or a fabric material, and in at least one exemplary embodiment, may include a polyester woven fabric made from spun polyester yarns. In at least one further embodiment, the use of spun polyester yarns may desirably increase the effective surface area and / or fibrillation of the fabric material at the micro 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) reduce the amount and / or width of “free space” through and / or within the openings in the fabric, thereby potentially reducing the separation distance between the fabric surface and microorganisms (in the influent / effluent liquid), and / or (3) modify and / or induce changes in the water quality within the enclosure in various ways. The decreased average opening size of the fabric may desirably increase the “filtration” of liquids, reducing and / or preventing various biological organisms and / or other materials from entering the enclosed or bounded environment, while the reduced “free space” within the opening(s) may 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 measurement of the size and / or viability of micro and macro organisms (as well as various organic and / or inorganic contaminants and / or other compounds) entering and leaving the enclosure. Further, these aspects will also desirably reduce the amount, degree, and / or rate of biofouling or other degradation that may occur within the enclosure material itself and / or within its opening(s), desirably maintaining the flexibility, permeability, and / or other properties of the enclosure fabric over a long period of time.

[0027] Preferably, at least a portion of the cloth wall of the enclosure is window-formed and / or perforated to such an extent that an amount of liquid and / or other substance(s) can pass through and / or "filter" through the wall of the enclosure in a relatively controlled and / or metered manner (i.e., from an external or "open" aqueous environment to a distinct aqueous environment, and / or from a distinct aqueous environment to an external or open aqueous environment), preferably providing a specific level, amount, and / or percentage of "bulk liquid flow" and / or "total liquid exchange" occurring between the distinct environment (inside the enclosure) and the surrounding open aqueous environment (outside the enclosure), as well as the potential to diffuse or otherwise pass through the enclosure walls and / or their pores. These movements of liquid and / or other compositions, in combination with various natural and / or artificial processes, preferably induce, promote, and / or form a relatively "different" or dynamic "artificial" environment inside the enclosure, particularly one with characteristics that differ in many ways from the dynamic characteristics of the surrounding aqueous environment, preferably providing a distinct environment that is "undesirable" for many biofouling organisms, thereby reducing and / or eliminating the occurrence of biofouling inside and / or immediately outside the enclosure. Additionally, the presence of numerous small perforations in the walls of the enclosure preferably 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 having an adverse effect on organisms outside the enclosure that can pass near or through the enclosure walls.

[0028] As an example, the amount of dissolved oxygen in the liquid within the enclosure will desirably be significantly different from the amount of dissolved oxygen in the liquid of the external aqueous environment, and the change in dissolved oxygen in the differentiated liquid potentially reflects, tracks, and / or "lags" (changes the amount) the dissolved oxygen level in the external aqueous environment. Desirably, this dissolved oxygen level in the differentiated liquid will typically be less than the level of the surrounding aqueous environment (although in various embodiments, including periodic and / or continuous cases, it can be above the level of the surrounding environment), and in various embodiments, the dissolved oxygen level can vary above a value that promotes the activity of sulfate-reducing or similar bacteria (i.e., microbiologically induced corrosion - "MIC") and / or other anaerobic decomposition / corrosion, and the variation itself desirably helps to inhibit and / or control the predominance of any single undesirable type or group of micro and / or macro organisms within the enclosure or its various sections or parts.

[0029] In various embodiments, gradients of dissolved oxygen and / or other chemical constituents of water can develop within the liquid of the enclosure between the inner wall of the enclosure and the outer surface of the substrate being protected, the gradient potentially creating a "more favorable zone" proximate to the inner wall of the enclosure and / or a "less favorable zone" proximate to the surface(s) of the substrate, and in some embodiments, inducing various microorganisms to move towards the inner enclosure wall and / or away from one or more surfaces of the substrate (e.g., due to an increased percentage of dissolved oxygen that may be present closer to the enclosure wall), potentially discouraging some microorganisms from colonizing, adhering, multiplying, and / or growing on the surface(s) of the substrate. In various embodiments, this gradient can result, at least in part, from the inflow of water through and / or into the enclosure and / or, at least in part, from the outflow of water through and / or out of the enclosure. The resulting "exchange" of water within and / or outside of the enclosure, and the various concentrations of chemicals and / or compounds contained therein, will desirably reduce the amount, degree, and / or rate of biofouling or other degradation that can occur on the substrate in its native (i.e., unprotected) state.

[0030] In various embodiments, water or other aqueous media entering and / or exiting the enclosure will desirably achieve this passage primarily in a “bulk” mode, minimizing localized variations in the velocity and / or “flow” of the water within the enclosure. The resulting relatively quiescent nature of the water within the enclosure will desirably reduce and / or inhibit significant “mixing” of the water within the enclosure, leading to a higher level of stratification and / or differentiation within the enclosure, which may include stratification based on oxygenation levels (i.e., chemoclines) and / or other properties (i.e., salinity, density, temperature), potentially leading to the formation of localized regions of anoxia and / or euxinia 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). Further, the water exiting the enclosure, which may contain various metabolic wastes and / or harmful compounds (including “toxins” of various known and / or unknown microorganisms) and / or other inhibitory compounds produced within the differentiated environment, will desirably “remain” within the pores of the enclosure and / or in the vicinity of the outer wall of the enclosure for various lengths of time within such a “swarm” of such water / compounds, desirably reducing and / or preventing colonization of the enclosure wall (including the outer-facing wall) by fouling organisms.

[0031] In one exemplary embodiment, the enclosure can be utilized in proximity to a substrate so as to create an oxygen-depleted zone within the enclosure, with at least a portion of this oxygen-depleted zone being in proximity to or in contact with the substrate. In some embodiments, the oxygen-depleted zone can include the entire differentiated aqueous environment (i.e., within the enclosure), while in other embodiments, the oxygen-depleted zone can include only a portion of the differentiated aqueous environment. Desirably, the various aspects of the unique design and placement of the enclosure will allow one or more natural processes to initially create the oxygen-depleted zone, although in some embodiments, additional measures and / or activities are taken to initiate, accelerate, maintain, delay, reduce, and / or supplement one or more natural processes, 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 be different from those located outside the enclosure. Further, the enclosure may form a plurality of distinct environments within the enclosure, and the plurality of distinct environments may be quantified as being "proximate to the inner wall of the enclosure" (i.e., within, for example, a few millimeters of the inner wall of the enclosure) and a second distinct "environment" that can be quantified as being proximate to the outer surface of the substrate (i.e., within a few millimeters). In various exemplary embodiments, a given distinct environment may induce or enhance the formation of one or more biofilms within the enclosure, which may include the formation of a biofilm on the surface of the substrate, and this biofilm may be different in various ways from the biofilm that can be formed on the substrate in an aqueous environment in the absence of the enclosure and / or from different biofilms on the inner surface of the enclosure wall or within the pores of the enclosure wall. For example, the substrate biofilm within the "enclosed" or distinct environment may incorporate a lower / fewer 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 cases, this distinct biofilm may be advantageous for preventing and / or reducing micro- and / or macrofouling of the substrate.

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

[0034] In various embodiments, the presence of the enclosure and any perforations through it can create a "distinct" aqueous environment that may not promote micro- and / or macrofouling of the substrate more than the surrounding aqueous environment, and may include the presence and / or existence of biofilm seeding in the distinct aqueous environment at a lower positive level than the biofilm seeding cues in the surrounding aqueous environment. Desirably, the enclosure will create a "difference" in the composition and distribution of various environmental factors and / or compounds in the distinct aqueous environment compared to similar factors and / or compounds in the surrounding open aqueous environment, and these "differences" will inhibit and / or prevent significant amounts of biofouling that occur (1) on the surface of the protected substrate, (2) on the inner wall surface of the enclosure, (3) within the openings and / or gaps of the walls of the enclosure, and / or (4) on the outer wall surface of the enclosure. In some embodiments, the enclosure will create a gradient of seeding cues within the enclosure that induces and / or promotes the positioning of some and / or all of the micro- and / or macrofouling organisms at a distance from the substrate, while in other embodiments, the enclosure can create a microenvironment in proximity to the substrate that does not promote biofouling and / or other degradation of the substrate. In yet other embodiments, the enclosure can be positioned in proximity to and / or in direct contact with the substrate, such as being wrapped directly around the substrate, and still provide the various protections described herein.

[0035] In various other embodiments, the presence of the perforated enclosure wall can similarly affect the distinct environment and / or various water chemical composition factors and / or the presence / absence of nutrients and / or waste within that portion as compared to that of the surrounding aqueous environment. For example, pH, total dissolved nitrogen, ammonium, nitrates, nitrites, orthophosphate, total dissolved phosphate, and / or silica can vary between the distinct environment and the surrounding open aqueous environment, and within the distinct environment, such nutrient levels can vary across the enclosed or bounded aqueous region. Generally, the water chemical composition, nutrient levels, and / or waste metabolite levels in the liquid within the enclosure at locations proximate to at least a portion of the enclosure wall (i.e., the "upstream portion" based on the direction of the bulk water flow) can approach the levels of the liquid outside of the enclosure, and greater variations are typically seen within the enclosure and / or proximate to the substrate surface.

[0036] In various embodiments, the presence of an enclosure as described herein can prevent organisms from growing (including being unable to grow at the same rate as equivalent organisms located outside the enclosure), prevent organisms from reproducing, and / or prevent these organisms from undergoing one or more of the natural processes and / or stages required to become fully functional macrofouling organisms, due to various "uncomfortable" conditions in a distinct environment, such that fouling organisms that can land on a substrate may not be able to settle or adhere to the substrate and / or may not be able to reproduce and / or colonize on the substrate, and the chemical composition of the water can be changed. For example, various chemical composition changes can occur within the enclosure (compared to the surrounding open aqueous environment), including a decrease in dissolved oxygen levels, a change in pH, nutrient levels and / or concentrations, waste levels, and / or a difference in the lack of movement of water within the enclosure. In many cases, fouling organisms may also be cut off and / or "killed" from a surface that is already contaminated when the substrate is placed within the various enclosures described herein, which can potentially stop and / or reduce fouling of the substrate and can potentially release and / or exfoliate some existing biofouling organisms and / or the remains of skeletons such as shells, skeletons, exoskeletons, and / or associated support structures from the contaminated surface(s).

[0037] In various embodiments, the placement, small size and / or distribution of the perforations in the walls of the enclosure, and the presence of the various sutures and / or suture portions (i.e., cilia) located therein, can 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 its various parts, which, in particular, when the enclosure is utilized near the surface of an aqueous environment or near such other energy sources, includes restricting and / or preventing various energy sources (such as sunlight for photosynthesis) from being immediately available for use by various microorganisms and / or other degradation processes. Optionally, the availability or presence of such energy sources (i.e., through the perforations) proximate to the walls of the enclosure can induce some motile organisms to aggregate and / or gather in proximity to the inner wall of the enclosure, and desirably, reduce their presence proximate to the substrate surface to be protected. In various alternative embodiments, the light or other energy source can be positioned within the surrounding aqueous environment proximate to the enclosure and / or can continue to reside within the enclosure at various locations including proximate to the protected substrate, thereby enhancing the availability of such energy sources proximate to and / or within the enclosure. Such embodiments can be particularly useful in limiting the presence and / or growth of biofouling organisms sensitive to the added energy source (i.e., providing a light source to inhibit zebra mussels, which typically prefer a darker environment, etc.).

[0038] In various embodiments, the placement, small size and / or distribution of the perforations in the walls of the enclosure, and the presence of various sutures and / or suture portions therein, can limit, prevent and / or regulate the location and / or amount of faster, bulk flow(s) that can occur within the enclosure or its various parts, and can include limiting and / or preventing various types of laminar and / or turbulent flow(s) (i.e., localized flow or “jets” of water) of the liquid within the enclosure and / or proximate to the substrate. In some embodiments, the relatively “slow” but not completely “static” nature of the water achievable within the enclosure can prevent a significant number of non-sessile microorganisms from coming into contact with the substrate or the boundary layer proximate thereto. Further, the restricted flow of the liquid within the enclosure can allow for a thinner / thicker aqueous liquid boundary layer to be present proximate to the protected substrate and / or enclosure wall, which further limits microbial or other contact with the protected substrate and can induce or allow for the formation of a thinner / thicker biofilm layer on the substrate than would typically be present in the more active flow situation(s) of an open aqueous environment.

[0039] In at least one alternative embodiment, the various advantages of the present invention can be provided by an impermeable enclosure (including, for example, plastic, wood and / or metal wall sheets or plates) that incorporates supplementary, and / or artificial, water exchange mechanisms such as a power pump or “check valve” arrangement, a propeller system and / or a petal system that provide a desired level of water exchange between the distinct aqueous environment and the surrounding open aqueous environment.

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

[0041] In some embodiments, the enclosure can provide varying degrees of biofouling protection to both the substrate and the enclosure wall in the absence of supplemental biocides or other fouling protection substances, inhibitors, and / or toxins that can be integrated into the enclosure structure and / or provided supplementally. For example, when an enclosure as described herein is placed around a substrate to form the disclosed distinct environment(s), the environment(s) can also exhibit elevated concentrations of various metabolic wastes, and various processes and / or metabolic activities occurring within the enclosure can produce one or more substances (e.g., hydrogen sulfide or NH 3 -N ammoniacal nitrogen, etc.) that are harmful, detrimental, toxic, and / or otherwise have an adverse effect on fouling organisms. For example, NH 3-N is ammonia in its undissociated form, also known as free ammonia nitrogen (FAN) or ammoniacal nitrogen, and has been found to be harmful and / or toxic to microorganisms because it can permeate cell membranes. In some embodiments, the desired concentrations of such harmful compounds (including "toxins" of various known and / or unknown microorganisms) and / or inhibitory compounds can be expressed within the enclosure (and these concentrations can then be continuously "replenished" by various processes occurring within the enclosure), they are present in distinct aqueous regions within the enclosure, and / or can elute through the wall of the enclosure, potentially creating a localized "swarm" of harmful chemicals that protects the outer wall of the enclosure to some extent from fouling organisms. However, once these compounds exit the enclosure, these harmful and / or inhibitory compounds can become rapidly diluted and / or decomposed by various natural processes, thus removing significant concerns regarding the longer-term effects of these substances on the environment at some distance from the enclosure. Additionally, because the processes for creating these compounds within the enclosure are continuous and / or periodic, the enclosure can continuously and indefinitely generate and / or elute these inhibitory compounds at relatively constant levels without the need for an elution reservoir and / or external replenishment or external power source.

[0042] In at least one exemplary embodiment, the enclosure may include a permeable, formable fibrous substrate of polyester fabric made from spun polyester yarns, which may be coated on at least one side (such as the surface facing the outside of the enclosure) with a biocidal compound or coating or a paint containing a biocide, and at least a portion of the biocide compound penetrates at least a portion of the path into the interior of the fabric. In at least one further embodiment, the use of ring-spun polyester yarns may desirably increase the effective surface area and / or fibrillation of the fabric material on a microscopic and / or microscale, which may desirably result in (1) a significant reduction in the average size of the natural openings extending through the fabric, and / or (2) a reduction in the amount and / or width of the "free space" through and / or within the openings in the fabric, thereby potentially reducing the separation distance between the microorganisms (in the influent / effluent liquid) and the biocide coating(s) residing on the fabric. The reduced average opening size of the fabric in such embodiments may desirably increase the "filtration" of liquids and 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) may desirably improve or amplify the effect of the biocide on the organisms passing through the enclosure (including an improved potential for direct contact occurring between the biocide and the various organisms). These factors will desirably result in a significant reduction in the size and / or viability of the micro and macro organisms (as well as various organic and / or inorganic contaminants) passing through the enclosure. Further, the presence of the biocide coating(s) and / or paint(s) and / or additive(s) on and / or within the fabric of the enclosure may desirably significantly reduce the amount, degree and / or rate of biofouling or other degradation that may occur within the enclosure material itself and / or within its openings, and desirably maintain the flexibility, permeability and / or other properties of the fabric of the enclosure over a long period of time.

[0043] In some embodiments and / or in some aqueous environments, the presence of a biocide coating on at least the outer surface of the flexible enclosure material will desirably reduce the thickness, density, weight and / or extent of biofouling and / or other degradation received on and / or within the openings within the enclosure itself, which will optimally maintain the desired level of water exchange between the enclosure and the surrounding environment, and / or extend the service life of the enclosure at the desired location of the enclosure around the substrate. In many situations, biofouling of the enclosure significantly increases the weight and / or rigidity of the enclosure, damages the enclosure and / or the structure attached to the enclosure (including the substrate itself), and can adversely affect the buoyancy of the enclosure and / or any object attached thereto. In addition, biofouling of the enclosure itself can reduce the flexibility and / or ductility of various fabric components, cause premature breakage and / or failure of the fabric and / or associated attachment mechanisms in a dynamic aqueous environment, and / or contribute thereto. Further, biofouling formation on / within the enclosure can potentially "block" or reduce the size of the openings through and / or within the enclosure fabric, and / or close the openings, potentially changing the permeability and / or liquid exchange rate between the differentiated environment and the surrounding dynamic and / or open aqueous environment, 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 can include an initial biocide treatment that elutes and / or is otherwise dispensed for a limited period of time after deployment of the enclosure, during which other characteristics of the enclosure enable the differentiated environment to develop, and the differentiated environment produces various inhibitory substances such that after the elution of the initial biocide has decreased to a lower and / or less effective level and / or after elution or dispensing has ceased, subsequent biofouling protection can be provided to the substrate and / or the enclosure. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0046]

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[0047] The disclosure of the various embodiments described herein is provided with sufficient specificity to meet legal requirements, but these descriptions are not necessarily intended to limit the scope of the claims. The subject matter of the claims may be embodied in many 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 the arrangement of individual steps or elements is explicitly described.

[0048] Disclosed herein are various easily assembled and / or easily used enclosures and / or other devices that can be positioned around, within, above, and / or below a substrate or other object located in (or disposed within) an aqueous environment or aqueous holding tank susceptible to biofouling. In various embodiments, systems, devices, and methods are disclosed that can protect an immersed and / or partially immersed substrate or other object (or a portion thereof) from the effects of aqueous biofouling, including the formation and potential retention of biofouling resistance by the substrate for a period of time after the enclosure has been opened and / or removed.

[0049] In various embodiments, protective enclosures can 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 jute fabrics (or various combinations thereof). In various embodiments, the enclosure has waste and / or biodegradable characteristics that allow the enclosure or a portion thereof to become uncoupled from the substrate and / or support structure, decay, and / or otherwise degrade after a certain amount of exposure to an aqueous environment, and can include degradation and / or peeling after formation of a desired biofilm or other layer on the substrate.

[0050] In various embodiments disclosed herein, the terms "distinguished aqueous environment" and / or "local aqueous environment" broadly encompass some and / or all of an aqueous area whose chemical composition of water has been or is expected to be changed due to the influence and / or presence of the enclosure, and can include one or more (and / or any combination thereof) of: 1) any water inside the inner wall of the enclosure (i.e., the "enclosed" or "distinguished" aqueous environment), 2) any water in any pores or spaces between the inner and outer surfaces of the enclosure (i.e., the "entrained" aqueous environment), and / or 3) any water in immediate proximity to the outer surface of the enclosure (i.e., the "proximate" aqueous environment).

[0051] In some embodiments, the enclosure may substantially surround and / or enclose the outer surface of the substrate, while in some alternative applications, the enclosure may desirably be positioned and / or configured to protect the substrate adjacent to and / or located outside the enclosure, and the "open aqueous environment" may be considered to be located within the enclosure, and the "enclosed" or "differentiated" aqueous environment may be positioned between the outer wall of the enclosure and the inner wall of the substrate. For example, in a water storage tank, the inner wall 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 required to be protected. In such cases, an enclosure as described herein may be positioned around the water inlet (or the enclosure wall may be positioned at a point between the water inlet and the tank wall), and the enclosure may desirably form a "different" environmental condition(s) close 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 that potentially involve "filtration" and / or "backwashing" of the liquid using the enclosure and / or a portion thereof, the "open aqueous environment" may be considered to be the upstream source of the aqueous water (or other liquid) before passing through the enclosure wall, and the "differentiated 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 be arranged along the inner wall of a water tank, a holding cell, or a distribution unit.

[0053] In various alternative embodiments, "surrounding" the substrate described herein includes partially surrounding the substrate with an enclosure to an extent sufficient to induce some and / or all of the desired filtration and / or change in the chemical composition of the water proximate to the protected substrate, and includes an enclosure that does not completely seal or isolate the substrate from the surrounding aqueous or other environment. For example, an enclosure that protects the hull of a boat or ship or other immersed and / or partially immersed portion may include only 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 towards other objects such as wooden structures, rock faces, solid metal sheets, etc., and yet the hull may be considered to be "surrounded" as described herein. In a similar manner, an enclosure having various breaks, openings, seams, cracks, fissures, and / or missing wall elements may desirably have an enclosure structure sufficient to induce some and / or all of the desired change in the chemical composition of the water and / or filtration function to occur proximate to the enclosure and / or the protected substrate, thereby protecting the enclosure and / or the 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, the substrate may be considered to be "surrounded" 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 an enclosure wall that is proximate to and / or in contact with the bottom surface of the harbor floor. In at least one possible embodiment, the enclosure may include the feature of partially and / or completely "sealing" certain portions of the enclosure against a breakwater, a hull portion, a larger hull, a submerged and / or partially submerged structure, and / or other objects such as the bottom surface / mud of the sea floor. In other embodiments, the enclosure may desirably include a depth sufficient to provide the biofouling protection described herein, but be shallow enough to avoid touching the bottom of the aqueous medium at low tide (i.e., for example, a submerged depth of 3 feet, 6 feet, and / or 9 feet). If desired, the bottom portion of the vertically oriented sheet may include window-forming, 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 sea floor.

[0055] In various embodiments, a skirt-type protection system may include individual elements of an enclosure or “skirt” that includes a plurality of vertically oriented “sheets” or similar structures that can be deployed in the water around an object or a portion thereof, extend downwardly beneath the object to be protected, and, in some embodiments, extend into a portion of the euphotic zone (i.e., the sunlit zone) of the water body, with a portion of the sheet, the protection system preferably creating a partially or fully shaded zone of water (i.e., a zone that is not well illuminated) adjacent to the object or, preferably, inducing and / or maintaining a change in the desired chemical composition of the water adjacent to the protected object that inhibits biofouling, forming a partially or fully bounded region of water. In various embodiments, the protection system may preferably further induce a degree of transmissivity change to sunlight passing through it, which, in some embodiments, involves incorporating barrier materials such as sheets, meshes, screens, and / or other obstacles to reduce and / or eliminate the passage of sunlight (and / or various wavelengths and / or their components) between the object and the upper portion of the enclosure wall, reducing and / or preventing the passage of a substantial amount of available sunlight (i.e., sunlight available to organisms) into this shaded zone through the upper portion of the enclosure. In various embodiments, these barrier materials may also inhibit or prevent the physical mixing of oxygen with the water within the barrier due to the action of waves and / or wind.

[0056] In other embodiments, the skirt or outer enclosure may be disposed around an offshore oil platform that preferably reduces and / or eliminates biofouling around various portions of the platform's support structure or "legs." In such embodiments, the enclosure wall may extend vertically downward into the water from a drum-type dispenser or "float" (or may be fixed directly to the platform and / or the legs) and may be deployed around most of the outer perimeter of the entire support structure, and the depth of the enclosure wall(s) may be increased and / or decreased as needed. Preferably, the enclosure wall(s) may 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 chemical composition of the water in the enclosed or bounded body of water, including portions of the enclosed or bounded body of water that are shallow and / or close to the surface. Optionally, one or more of the enclosure walls may be raised and lowered when desired, which may induce a desired change in the chemical composition of the water when the chemical composition of the water is being monitored (i.e., e.g., around the rig or at a remote monitoring station). Similarly, one or more openings, partitions, and / or partitions within or between the enclosure walls may be opened and / or closed as needed, preferably to change the chemical composition of the water in a desired manner.

[0057] If desired, the fouling prevention system may include a free-floating enclosure, and the enclosure walls may be supported by a floating boom that can surround or enclose the protected vessel. In various embodiments, the disclosed structures and / or their components may be directly attached 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, and the enclosure walls are connected to adjacent dock(s) and / or other structures. If desired, a submerged hanging curtain or other movable wall structure may be provided proximate to the stern of the boat to close the opening “U” section and 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 a submerged wall of the enclosure, and the submerged wall 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 a portion thereof to be raised and / or lowered to allow a ship to float into and / or out of the enclosure in a normal manner (i.e., when the curtain section has been lowered by a sufficient amount, the ship can float into and out of the enclosure over the lowered curtain section). As another alternative, one or more sections of the enclosure wall material and / or part or all of the support structure(s) (i.e., support pipe or wire cable support) may “slide horizontally” (in a manner similar to opening and / or closing a shower curtain) to allow entry into and / or exit from the enclosure. In this embodiment, the upper edge of the enclosure wall may be suspended at least 1 or 2 feet above the water surface so that water and / or wave action does not, preferably, penetrate above the upper portion of the enclosure wall (the enclosure preferably extends to a desired extent below the water surface).In various alternative embodiments, the suspended curtain and / or other structures can be attached to various surfaces, including the protected substrate itself, floating structures, fixed structures, water surfaces, underwater surfaces, and / or the bottom and / or subsurface harbor structures and / or the seabed of the water body. In some embodiments, direct contact of the enclosure with the seabed may not be desirable if stronger bottom currents and / or excessive sedimentation can occur, or if undesirable organisms on the seabed can penetrate 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 can be utilized to provide periodic biofouling protection to the protected substrate, which can include an interruption of biofouling protection when the water flow proximate to the protected substrate can increase, and the biofouling protection can potentially resume during periods when the water flow proximate to the protected substrate is reduced. For example, the enclosure can include one or more subsurface openings that can be automated and / or controlled by a user, which can be opened when increased water flow inside and / or outside the enclosure is desired. Such opportunities can include the removal of the substrate from the enclosure, the need to sample the water quality of the outside environment, and / or the need for a significant level of cooling and / or other water (e.g., through the immersed intake and / or discharge ports of the substrate's hull). In other embodiments, the enclosure can be designed to provide increased water flow through the enclosure walls for a desired period, which can reduce and / or remove some or all of the biofouling protection provided by the enclosure during the period(s) of increased flow, but can provide for the resumption of biofouling protection once the water flow rate decreases below a predetermined design threshold.

[0059] In at least one exemplary embodiment, the enclosure design can be provided with particular utility as an anti-biofouling and / or filtration system for a system that uses seawater and / or fresh water as a cooling water source. In this embodiment, a floating enclosure or “reservoir” in an aqueous environment can be provided, and the enclosure can contain a much larger quantity of aqueous fluid than is typically required by a cooling system on a normal usage basis. For example, if a cooling system requires 1000 gallons of water per minute during normal operation, the reservoir will 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 water. Desirably, a water inlet, which can 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 equipment, and water having a relatively high dissolved oxygen level will be drawn into openings or gaps in 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 deoxygenating agents in the water column will desirably reduce the dissolved oxygen level in the water, such that the dissolved oxygen level is somewhat depleted before moving into the inlet. However, in at least one alternative embodiment, the water inlet can be near the bottom of the enclosure and / or near the bottom surface of the reservoir, which is generally the coldest water in the enclosure / reservoir for use in the cooling equipment.

[0060] In at least one exemplary embodiment, a method for determining an appropriate design, size, shape, and / or other characteristics of an enclosure may desirably be utilized to determine a minimum recommended, enclosed or bounded volume and / or water exchange rate in order to reduce and / or eliminate biofouling within the enclosure. In some embodiments, such as a membrane filter configuration, where the enclosure may be utilized to provide a cooling water source and / or other source water for a manufacturing plant (i.e., a power plant, desalination plant, refinery and / or other manufacturing facility), the disclosed method may potentially be utilized to reduce and / or eliminate biofouling in 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 can potentially enhance, induce, and / or promote the formation of deposits of substrates and / or layers, biofilms, and / or materials on the enclosure walls under certain conditions, which reduces, repels, inhibits, and / or prevents micro- and / or macro-organisms from subsequently attempting to colonize, mobilize, and / or foul some or all of the protected substrate (i.e., provides a level of "biofouling inoculation" on the substrate). For example, the various embodiments of the enclosures disclosed herein can cause the creation 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 to the surface of the substrate. In many embodiments, the unique mixing and / or distribution of microorganisms / microflora within the enclosure can release compounds that, in combination with various surface bacteria, can affect the settlement, mobilization, and / or colonization of fouling organisms on the substrate, and can induce and / or guide the formation of biofilms or other layers of microorganisms on the substrate. In various embodiments, once a unique biofilm layer of microorganisms is established, this layer can maintain durability and / or self-renewability, which can continue to protect the substrate from a particular type and / or amount of biofouling for an extended period of time in the absence of the enclosure (i.e., where the enclosure can be temporarily and / or permanently removed and / or damaged).

[0062] In various embodiments, the 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 prevent such settlement, recruitment and / or colonization, chemicals and / or compounds that may lack cues for positive settlement, recruitment and / or colonization, chemicals and / or compounds that produce a lower level of cues for positive settlement, recruitment and / or colonization compared to the levels produced on the surface in the surrounding aqueous environment and / or chemicals and / or compounds that produce cues for positive settlement, recruitment and / or colonization for beneficial organisms (e.g., organisms that may generally not be considered significant biofouling organisms). In some embodiments, lacking specific "welcoming cues" on a protected substrate and / or associated biofilm may provide fouling protection extended to the substrate. In various embodiments, "welcoming cues" may include nutrients and / or chemicals that facilitate the settlement, recruitment, colonization, growth, and / or replication of micro- and / or macroflora that are required, desired, and / or on a given surface, and such "deterrent cues" may include waste metabolites and / or other chemicals that inhibit, prevent, and / or deter the settlement, recruitment, colonization, growth, and / or replication of micro- and / or macroflora on a given surface.

[0063] In various embodiments, fouling inhibition can be represented by a reduction in the total fouling coating of the substrate and / or the surface(s) / crevices of the enclosure by fouling organisms as compared to the total fouling coating of substantially similar substrates (without a protective enclosure) immersed and / or partially immersed in a substantially similar aqueous environment. This fouling reduction can be a reduction of 10% or more of fouling, a reduction of 15% or more of fouling, a reduction of 25% or more of fouling, a reduction of 30% or more of fouling, a reduction of 40% or more of fouling, a reduction of 50% or more of fouling, a reduction of 60% or more of fouling, a reduction of 70% or more of fouling, a reduction of 80% or more of fouling, a reduction of 90% or more of fouling, a reduction of 95% or more of fouling, a reduction of 98% or more of fouling, a reduction of 99% or more of fouling, a reduction of 99.9% or more of fouling, and / or a reduction of 99.99% or more of fouling. Alternatively, fouling inhibition of the protected article(s) can 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 can 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 an equivalent unprotected substrate exhibits a fouling coating 1 inch or more thick), which would reflect a reduction of more than one-tenth of 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 can exhibit less than 1% fouling, or a reduction of more than one-hundredth in the fouling level of the protected substrate and / or enclosure wall. In still other embodiments, the protected article can exhibit less than 0.1% fouling, which is a reduction of more than one-thousandth in the fouling level of the protected substrate and / or enclosure wall.In still 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 greater than or exceeding one ten-thousandth of the fouling level of the protected substrate and / or enclosure wall) compared to an unprotected substrate. ASTM D6990 and the Naval Ship 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, fouling inhibition can be represented by a reduction in the total coating increase of both the substrate and the enclosure surface by fouling organisms compared to the total increase in fouling coating of substantially similar substrates (i.e., without a protective enclosure) immersed and / or partially immersed in a substantially similar aqueous environment, which can be measured by visual inspection, physical measurement, and / or based on the increased weight and / or volume of the substrate and enclosure combination when removed from the aqueous medium (i.e., the increased weight due to the weight of the fouling organisms attached to them). This fouling reduction can be a reduction of 10% or more of fouling, 15% or more of fouling, 25% or more of fouling, 30% or more of fouling, 40% or more of fouling, 50% or more of fouling, 60% or more of fouling, 70% or more of fouling, 80% or more of fouling, 90% or more of fouling, 95% or more of fouling, 98% or more of fouling, 99% or more of fouling, 99.9% or more of fouling, and / or 99.99% or more of fouling.

[0065] Altered water regions 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 can be disposed around a substrate 40, and the open proximal end is sized to be large enough to pass over and / or around the entire substrate and / or any associated support structure, and the open proximal end can be sized, for example, to preferably separate or enclose an aqueous environment within the enclosure (i.e., a “distinguished aqueous environment” or “enclosed environment”) from the surrounding “open” aquatic environment. For example, a drawstring or pull-wire type closure 50 can be used to reduce the size. Desirably, once the enclosure is “separated,” “enclosed,” or otherwise closed in this manner, a certain amount of liquid from the open environment can still permeate through the walls of the enclosure and into the distinguished environment, and similarly, a certain amount of liquid from the distinguished environment can still permeate through the walls of the enclosure and into the open environment.

[0066] One important feature of the present invention is that the enclosure can form a "distinct aqueous environment" in proximity to the substrate, while also allowing for a controlled amount of "mixing" and / or other transport between the liquid and / or other substances within the enclosure and the liquid and / or other substances in the surrounding aqueous environment (i.e., outside the enclosure). This controlled transport, which can occur both inside and / or outside the enclosure, preferably forms a unique aqueous environment within a portion of the enclosure that inhibits and / or prevents a significant amount of biofouling from forming on the substrate. For example, dissolved oxygen in seawater can be derived from one of three sources: (1) oxygen in the atmosphere that dissolves, diffuses, and / or mixes (i.e., by aeration) into the water surface; (2) oxygen released by algae, aquatic plants, and / or other biological processes resulting from photosynthesis or other metabolic pathways; and / or (3) oxygen present in the water flows of creeks and rivers that mix into the seawater. When appropriately designed and deployed in a suitable environment, the enclosure structure preferably blocks and / or inhibits a significant amount of sunlight from penetrating into the distinct aqueous environment, thereby reducing the amount of dissolved oxygen supplied by photosynthesis within the enclosure. In addition, the presence of the enclosure wall preferably reduces and / or inhibits the physical bulk flow of water into, through, and / or out of the enclosure due to horizontal and / or vertical water currents (or combinations thereof) caused by various factors. This is because the enclosure wall can bend to various degrees, allowing the wall to provide at least a partial barrier to the water current, while also enabling the wall to change its shape and / or orientation to some extent to reduce flow resistance, and because the flexible enclosure wall can "move" and / or deform to various degrees with the water current, reducing the pressure differential that drives the water flow through the pores of the wall fabric.

[0067] In at least one exemplary embodiment, when the enclosure of the present invention is first placed around a substrate, dissolved oxygen in the distinct aqueous environment can be rapidly depleted from within the enclosure by biological, metabolic, and / or other processes and / or activities within the enclosure that create an oxygen-depleted region within the enclosure. However, to the extent that 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 inflow of oxygen-saturated water through the enclosure walls, and some amount of oxygen-depleted water will exit from the enclosure walls. Generally, oxygen replenishment into the enclosure occurs at a slower rate than that typically utilized by the microflora and / or microfauna of the open body of water, which induces and / or forces at least some of the microflora and / or microfauna within the enclosure to alter their activities, behavior, reproduction, metabolism, diversity, composition, and / or relative distribution to adapt to the artificial conditions within the enclosure, and also affects various natural chemical processes such as oxidation and / or free radical activity. Further, since the oxygen levels and / or exchange rates of the open body of water vary due to various factors (such as day / night cycles, currents / tides, and / or other water movements, water aeration due to wind and / or storm activity, etc.), the inflow of dissolved oxygen will vary, which will change the levels of oxygen and / or other chemicals within the enclosure, which will induce further changes in the activities, 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 fouling organisms from colonizing, mobilizing, growing, and / or forming colonies on the substrate, and will also induce a unique mix of metabolic and / or other processes that will occur within the enclosure.

[0068] Figure 8A illustrates the dissolved oxygen levels within various enclosure embodiments that have been immersed in seawater over a period of several months. For each of these embodiments, the dissolved oxygen level within the enclosure is generally lower than that of the surrounding open water, creating an artificial environment for the microflora and / or microfauna within the enclosure to alter their activities, behaviors, reproduction, metabolism, diversity, composition, and / or relative distribution in order to adapt to these artificial conditions. Further, as shown in Figure 10A, the artificial conditions within the enclosure are constantly changing, and the dissolved oxygen level within the enclosure (i.e., the lower line labeled "spun polybag") "follows" or "lags" behind the changing oxygen levels outside the enclosure.

[0069] Generally, changes in the net amount of dissolved oxygen within an enclosure as described herein are due to subtracting from any inflow of dissolved oxygen contained in the water flowing into the enclosure through the enclosure walls (i.e., typically, an increased oxygen source), the amount of oxygen consumed within the enclosure (i.e., a decreasing oxygen source) by oxidation or similar processes, and / or metabolic processes of the flora and / or fauna therein (and any flow of dissolved oxygen of deoxygenated water flowing out of the enclosure to some extent). When the external dissolved oxygen level is higher and / or the water inflow brings more oxygen into the enclosure than is consumed within the enclosure and / or exits the enclosure, the net oxygen level within the enclosure should increase to some extent. When the external dissolved oxygen level is lower and / or the water inflow is slow and brings less oxygen than is consumed within the enclosure, the net oxygen level within the enclosure should decrease to some extent. Thus, the dissolved oxygen level within the enclosure "reacts" or "lags" behind the dissolved oxygen level of the water surrounding the enclosure, and the DO level of the enclosure is typically (but not always) below the DO of the surrounding water. Further, as best seen in FIGS. 10A and 10B, the DO level within the enclosure (the lower line labeled "spinning polybag") often generally resembles the daily and / or seasonal variations of the dissolved oxygen outside the enclosure (the upper line labeled "open configuration"), although at a reduced level. Each of these changes in the differentiated environment will, desirably, further vary their activities, behaviors, reproduction, metabolism, diversity, composition, and / or relative distribution in order for the macrofouling and microflora and / or macrofouling and microfauna within the enclosure to adapt to the changes within the artificial conditions.

[0070] In addition to inducing a dissolved oxygen level that is generally lower than the dissolved oxygen level outside the enclosure, various embodiments of the present invention can reduce and / or limit the amount of variation between the highest and lowest oxygen levels in an open environment, and additionally have the ability to reduce or "smooth out" many of the transient variations in oxygen levels that can contribute to fouling in an open environment. Such moderation or smoothing of the DO level within the enclosure can be seen in FIGS. 10A and 10B, where the variation in dissolved oxygen within the enclosure undergoes a much smoother change than the variation in the open water, and the change in the DO level within the enclosure is moderated or smoothed compared to the more "jerky" and / or rapid changes in the DO level in the open environment outside the enclosure.

[0071] In various enclosure embodiments, the dissolved oxygen level in the local aquatic environment is desirably maintained above other dissolved oxygen levels, on average over a 24-hour period, or at a concentration that is 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% higher. However, in some embodiments, it may even be acceptable and / or desirable for the dissolved oxygen level in the enclosure to be reduced to an anoxic level, which may include an oxygen concentration of less than 0.5 milligrams of oxygen per liter of liquid in some or all of the enclosure. Such anoxic conditions are desirably not maintained for long periods, but rather are relatively transient phenomena 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, substrate to be protected, associated season(s), local fouling pressure, and / or other factors. Desirably, such reduced and / or anoxic oxygen levels will not be maintained for a period of time that is significantly harmful to the underlying substrate and / or the structure of the enclosure.

[0072] The reduced dissolved oxygen levels that occur within the enclosure can significantly contribute to reducing biofouling of the substrate in that the reduced availability of oxygen can make it difficult for certain fouling organisms to colonize and / or reproduce within the enclosure and / or on the substrate. Additionally, the reduction of dissolved oxygen levels within the enclosure can increase the formation of wastes such as hydrogen sulfide and / or ammoniacal nitrogen (i.e., free ammonia nitrogen, nitrogen-ammonia or NH 3 -N), and / or can significantly reduce the opportunity for other organisms to process and / or eliminate such wastes, both hydrogen sulfide and ammoniacal nitrogen being harmful and / or even toxic to various aquatic organisms and / or microorganisms. For example, FIG. 12A illustrates the biologically occurring nitrogen cycle that occurs naturally in various water bodies, which can significantly contribute to the reduction of free oxygen within the enclosure, and FIG. 12B graphically illustrates an exemplary dependence of NH 3 -N on the available dissolved oxygen levels. Additionally, in some embodiments, the anaerobic ammonia oxidation reaction can potentially be initiated and / or sustained by bacteria within the enclosure, which can also produce hydrazine and / or other by-products that inhibit marine growth. Generally, the concentrations of these by-products are higher inside the enclosure than outside the enclosure (however, various of these harmful compounds, including various known and / or unknown microbial "toxins" and / or inhibitory compounds, can elute through the walls of the enclosure at various rates), and in some embodiments, the individual concentrations and / or comparative ratios of these by-products within the enclosure can vary for various reasons.

[0073] For example, in various embodiments, the enclosures described herein can induce the formation of metabolic wastes, toxins, or other inhibitory compounds such as NH 3 -N at concentrations in the range of 0.53 mg / L to 22.8 mg / L within the enclosure, which can be toxic to various freshwater organisms (typically depending on pH and / or temperature). In other embodiments, the NH 3The concentration of -N can range from 0.053 to 2.28 mg / L, which can inhibit the formation of biofouling within the enclosure and / or on the outer surface of the enclosure. In addition, at a low level of NH 3 -N of about 0.002 mg / L or more, the ability of various aquatic flora and / or fauna to form colonies and / or reproduce can be significantly reduced.

[0074] In some exemplary embodiments, fluctuations and / or changes in the individual levels of the chemical constituents 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), are further proposed to form an important aspect of some embodiments of the present invention in that the artificial environment formed within the enclosure will desirably "promote" and / or "inhibit" the growth of different macrofouling and microflora and / or macrofouling and microfauna at different times. Such continuous changes in the differentiated environment desirably continuously adapt and / or change the various organisms present within and / or in proximity to the enclosure to the new environmental conditions, which tends to inhibit the dominance of a single species or grouping of species within and / or in proximity to the enclosure. This can have the effect of enhancing competition among the various flora and / or fauna within the enclosure, which can inhibit and / or prevent the dominance of the enclosure by a single variety, species, and / or distribution of flora and / or fauna, thereby reducing the potential for a dominant species of bacteria or other micro- or macro entities to thrive and / or expend energy fouling the substrate or creating a substrate to which other fouling organisms can attach.

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

[0076] Another important aspect regarding the enclosures of many embodiments of the present invention is that the enclosures preferably inhibit, but do not completely prevent, the flow of water into and / or out of the enclosure under typical water conditions. In many cases, the substrate to be protected can be fixed, connected, attached, and / or fastened to one or more solid immovable objects, such as the seabed, an anchor, a wall, a pier, a pile, a quay wall, a wharf, other structures, etc., which can restrict the movement of the substrate to varying degrees with respect to the water in which the substrate is placed, and this can induce a certain level of bulk water flow through various surfaces of the substrate. However, the various embodiments of the enclosures described herein (typically attached to the substrate, its various support structures, and / or other adjacent objects) will preferably interrupt and / or impede to some extent the ambient flow of water immediately adjacent to the substrate surface, and more preferably will maintain a body of water that is enclosed or bounded in direct contact with the substrate under many water flow conditions. The various enclosure designs disclosed herein achieve this purpose 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 varying degrees in response to the impact and / or movement of the surrounding water area.

[0077] If desired, the enclosure may include a blade 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) that includes a flexible wall 152, a lower cap 153, and / or an upper end cap 154 that substantially surrounds the substrate 159 (i.e., the sensor or other structure), and may be formed in a shape approximating the size, shape, and / or general contour of the substrate (or a portion thereof) to be protected. FIG. 2 also illustrates a support 156 that supports the substrate 159 and / or substantially isolates the substrate 159 from the inner walls of the enclosure and / or end caps, and the enclosure assembly is attached to a rope or tether 158. If desired, such an enclosure design may be utilized to protect guards, support 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 exterior-facing gaps that may be particularly comfortable for biofouling organisms. In various designs, the exterior-facing walls of the enclosure are preferably flexible, including the side structure 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 “prehabs” and enclosures having prehabs or modular subdivisions that can be assembled into a final enclosure of the desired size, shape, and / or configuration. If desired, the enclosure may be designed in a relatively simple shape to accommodate a substrate having a very 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 very simplified exterior shape.

[0078] In various embodiments, it may be desirable for the permeable wall of the enclosure to remain separated from the surface of the substrate. On the other hand, in other embodiments, accidental, 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 thereby provided. In yet other embodiments, accidental, periodic, and / or constant contact between portions of the enclosure and various surfaces of the substrate may provide a significant improvement in the biofouling prevention effect of the enclosure. In some embodiments, the enclosure wall may be in direct contact with the protected substrate, such as when a fibrous matrix can be wound around substrates such as pipes, girders, and / or piles that are immersed and / or partially immersed.

[0079] In various embodiments, such as those shown in FIG. 3, the enclosure 310 may include one or more spaced or discrete sections 325 (i.e., separated from the substrate 300) that are located proximate to the bottom or lower portion 340 of the substrate 300, which do not remain permanently in direct contact with the substrate (i.e., to leave the "space" 330 between the deposit and the substrate) and may provide additional space within the enclosure for deposits 320 and / or other materials that are present or collected in a distinct environment. Such deposits may include dead, dying, and / or decaying microbial cells that are unlikely to exit through the openings within the enclosure, which may cause the "deposition" and / or "mud" of deposits that gradually rise within the enclosure. If desired, the openings within the enclosure of such a "lower area" may be larger and / or more numerous than the corresponding openings in other areas of the enclosure, and preferably, such deposits or other materials are allowed to pass through and / or be discharged from the enclosure over time, and the inflowing / outflowing liquid or water stream is allowed to "wash out" the deposits from the enclosure in a controlled manner. In other embodiments, the openings within the enclosure in such a "lower area" may be smaller and / or fewer in number, or, if desired, may be increased in number and / or size to allow for additional water exchange in certain situations, in order to minimize water exchange due to "upwelling" and / or "sedimentation" plumes of water that may be caused by local temperature variations.

[0080] In various descriptions of the present disclosure, "permeability" is due to the "ambiguity" and / or randomness in the architecture of this fabric, which can be incorporated by changes in the flexibility and / or form of the fabric under wet and / or dry conditions, and it can be somewhat difficult to measure and / or determine the "effective" porosity of the overall openings of the spun poly and / or jute fabric materials. Thus, desirably, it is used as an indicator of some aspects of the enclosure and / or its components, and the applicant believes it can be optionally important for the effectiveness of various embodiments of the disclosed systems and devices. In various embodiments, the enclosure can 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) can include tortuous or "bent" flow paths, and the tortuosity is defined as the ratio of the actual length (L t ) of the flow path to the straight-line distance between the two ends of the flow path:

Number

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

[0082] FIG. 4A illustrates a micrograph of one exemplary scanning electron microscope (SEM) of an exemplary spun yarn 400, which illustrates a central body or yarn bundle 410 of intertwined filaments 420, with various filament ends 430 extending laterally with respect 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 an enlarged view of a knitted fabric 450 including a PET spun yarn, a series of gaps or openings 480 are positioned between the yard bundles 470 during the knitting process, and one or more extending fibers or fiber ends 490 extend across the various openings (multiple fiber ends preferably traverse each opening in various embodiments).

[0083] In various embodiments, the enclosure wall and the substrate(s) protected therein can be separated and / or spaced apart by an average spacing 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 (i.e., between the inner wall of the enclosure and the outer surface of the substrate). In various alternative embodiments, at least a portion or all of the enclosure can be in direct contact with the substrate within one or more areas (including, but not limited to, the 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 distance between the enclosure wall and the substrate to fall within a specific range of an average distance, or the desired distance may be proportional to the width, length, depth, and / or other characteristics of the enclosure and / or the substrate to be protected. For example, maintaining a given distance between a smaller substrate and a smaller enclosure containing only a few gallons of water may be more particularly susceptible to the effects of water exchange levels and the resulting changes in the chemical composition of the water, especially when there is a relatively small amount of water in a distinct environment, compared to the distance between a relatively large hull and a large enclosure containing thousands or millions of gallons of water in its "distinct environment" within the enclosure. In such cases, the desired distance between the enclosure wall and the opposing surface of the substrate, depending on the substrate size, type, enclosure design, and / or the rigidity of the enclosure, and / or the design, may be 2% or less, 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. In another embodiment, the local aqueous environment may extend in a direction away from the surface of the substrate by a distance 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 inch or more, 0.1 inch or more, 0.04 inch 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 inch or less, 0.04 inch or less.

[0085] FIG. 5 illustrates an exemplary fabric material 100 in the form of a rolled sheet that can be used in various ways to form the various enclosures described herein. In this embodiment, the material preferably comprises a flexible fiber material, in this case a natural fiber fabric, as well as a woven, knitted, felted, non-woven and / or other structure of polyester or other synthetic fibers and / or various combinations thereof, a fabric material. In various embodiments, the fabric can be utilized to construct the various enclosure embodiments described herein and / or can be used to wrap or otherwise "coat" an elongate substrate with such a rolled sheet material and / or may be desirable, particularly where an unrolled and unrolled sheet can overlap other sheet sections that can create an "enclosure" comprising a progressively wrapped substrate (i.e., along a stake or support girder), the fabric material is wrapped around the substrate in an overlapping "barber pole" or maypole type technique, or serves as a lining for the inner wall 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 and for a very thin layer of liquid (and optionally liquid within the fabric itself) between the fabric enclosure wall and the substrate surface to constitute the "distinguished environment" described herein.

[0086] In various alternative embodiments, the enclosure and / or its component materials can include a three-dimensional fabric substrate and / or fibrous substrate structure formed from woven and / or intertwined strands of thread formed in a lattice, mesh, mat, or window-forming fabric arrangement, and in various embodiments, one or more non-flat and / or non-smooth fabric layer(s) can be incorporated. In one very simplified form, the enclosure can contain a plurality of horizontally positioned elements woven with a plurality of vertically positioned elements (and various combinations of other fiber elements aligned in various directions), which can include a plurality of separate and / or woven layers. The flexible material can include one or more spaced-apart layers that can include baffles or various interconnected sections. Desirably, each thread or other thread element(s) within the enclosure material will include a preselected number of individual strands, with at least a portion of the strands extending outwardly from the thread core element at various locations and / or in various directions, thereby creating a three-dimensional, curved and intertwined network of threads and thread strands woven into the fabric. In various embodiments, the various elements of the fibrous substrate can be aligned in virtually any orientation, including diagonally, or in a parallel fashion relative to each other, thereby forming right angles or a three-dimensional orientation, and / or a randomized distribution (i.e., felt mat) and / or pattern, and / or virtually any other orientation. Additionally, in some embodiments, there can be a significant spacing between individual elements, while in other embodiments, the spacing can be reduced to a very tight pattern to form a pattern with little or no space between. In various preferred embodiments, elements such as threads and / or fibers can be made of natural or synthetic polymers, but can also be made of other materials such as metals, nylon, cotton, or combinations thereof.

[0087] Various aspects of the present invention may involve the use of a highly fibrillated fibrous substrate and / or a flexible material, which means that the material may include curly whiskers or hairy appendages (i.e., fibers) protruding from its surface or within pores, or the open spaces of a three-dimensional flexible fabric forming a "filtering" medium. The curly whiskers or hairy appendages can be part of the material constituting the three-dimensional flexible filtering material or incorporated into the material. Alternatively, the curly whiskers or hairy appendages can be formed from a separate composition adhered or attached to the flexible material. For example, the curly whiskers or hairy appendages can be attached to and protrude from an adhesive layer that is itself attached to the surface of the flexible material. In aspects of the present invention, the curly whiskers or hairy appendages can protrude from the surface of the enclosure material, while in other aspects, the curly whiskers or hairy appendages can extend inwardly from the enclosure material and / or toward and / or into the fibrous substrate and / or other yarns and / or fibers of the fabric of the enclosure material. In various aspects of the present invention, the curly whiskers or hairy appendages can be elastic and / or can 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 curly whiskers or hairy appendages can also discourage the settlement of biofouling organisms on or within the surface of the enclosure.

[0088] The presence of numerous small fibers within 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 gaps of the woven pattern. This arrangement of fibers can further provide a more tortuous path for organisms attempting to enter the internal environment protected by the enclosure across the depth of the fabric (i.e., improve the "filtration" 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 microorganisms pass through the openings and / or pores of the material) will desirably provide a longer path, a larger surface area, and / or prove to be 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 effect of the enclosure in that such fabric construction can improve the "filtration effect" of the enclosure wall and / or can negatively 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 can include "flatter" and / or "smoother" materials such as textured yarns or other materials (and / or other material construction techniques) and can still provide many of the anti-biofouling effects disclosed herein. Such materials can be significantly flatter, smoother, and / or less hairy than materials incorporating spun polyester yarns, while still providing an acceptable level of biofouling protection for various applications.

[0090] A variety of materials that may be suitable to varying degrees for constructing the enclosure include a variety of natural and synthetic materials, or combinations thereof. For example, burlap, jute, canvas, wool, cellulose, silk, cotton, hemp, and muslin are non-limiting examples of useful natural materials. Useful synthetic materials can include, without limitation, polymer classes of polyolefins (such as polyethylene, ultra-high molecular weight polyethylene, polypropylene, copolymers, etc.), polyesters, nylon, polyurethane, rayon, polyamides, polyacrylics, and epoxies. Various types of glass fiber compositions can also be used. Combinations of polymers and copolymers can also be useful. These three-dimensional flexible materials can be formed into a fibrous structure, a permeable sheet, or other configurations that provide a structure capable of providing anti-fouling and / or filtration characteristics as described herein. Examples of potentially suitable flexible materials for use in constructing the enclosure described herein include, but are not limited to, burlap, canvas, cotton cloth, linen, muslin, a permeable polymer sheet, a cloth constructed from polymer fibers or filaments, and permeable films and membranes. In aspects of the present invention, the flexible material can be selected from natural or synthetic cloth such as burlap, knitted polyester or other cloth, woven polyester or other cloth, spun polyester or other cloth, various combinations thereof, or other cloth having various properties, including those shown in FIGS. 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., yarns). As used herein, "intertwined" means that the fibers can be non-woven, woven, knitted, braided, or otherwise commingled to produce a fibrous substrate capable of the various filtration and / or water permeability and / or water exchange characteristics discussed herein. The material in which the fibers are intertwined can desirably create a pattern of open and closed spaces in the three-dimensional flexible material, with the open spaces therein defining gaps. Desirably, the fibers that can make up the flexible material can be, for example, a single filament, a bundle of multiple filaments, filaments 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 mil or less, about 0.4 mil or less, about 0.3 mil or less, about 0.2 mil or less, or about 0.1 mil or less.

[0092] In some aspects of the present invention, the flexible material may include a woven fabric or a knitted fabric. For example, the woven fabric may have a pick count 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 approximately 20 ppi. In other aspects of the present invention, the woven fabric may have an end count 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 approximately 20 epi or approximately 24 epi. In still other various aspects of the present invention, the knitted fabric may have a course 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 approximately 36 cpi or approximately 37 cpi. In yet other aspects of the present invention, the knitted fabric may have a wale 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 approximately 36 wpi or approximately 33.7 wpi.

[0093] Thus, in at least one aspect of the present invention, the woven fabric has a yarn size density (i.e., the product of the weft per unit area of the warp) 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 aspect of the present 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 aspect of the present invention, the woven or knitted fabric has a basis weight per unit area of from about 1 to about 24 ounces per square yard (from about 34 to about 814 g / m2), from about 1 to about 15 ounces per square yard, from about 2 to about 20 ounces per square yard (from about 68 to about 678 g / m2), from about 10 to about 16 ounces per square yard (from 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 aspect of the present invention, a desirable woven fabric based on spun polyester fibers can be utilized as an enclosure material, and the fabric has a basis weight of about 410 grams per meter 2 (the weight of the base fabric before any coatings or modifications are included) (see Table 13).

[0096] In various exemplary embodiments, the thickness of a suitable enclosure or structural wall can range from 0.025 inches to 0.0575 inches or more, and desirable enclosures are 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 within the enclosure and the shape, size, and / or degree of tortuosity of the various openings within the enclosure, enclosures of thicknesses thicker and / or thinner than those specifically described can be utilized in various enclosure designs with various degrees of success and various enclosure materials. In various alternative embodiments, the flexible base materials, fibers, and / or threads utilized in the construction of the disclosed fibrous substrates can have wide variations in thickness and / or length depending on the substrate or particular application to be protected. For example, in some aspects of the present invention, the thickness of the flexible material can be from about 0.001 to about 0.5 inches, from about 0.005 to about 0.25 inches, from 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. Variations in thickness and permeability within a single structure such as a membrane filtration structure and its multiple layers are contemplated.

[0097] It should be understood that a wide variety of materials and / or combinations of materials can be utilized as the enclosure material to achieve the various purposes described herein. For example, a film or similar material can be utilized as one alternative to a cloth enclosure wall material that can include a permeable and / or impermeable film for part or all of the enclosure wall. Similarly, natural and synthetic materials such as rubber, latex, thin metals, metal films, and / or foils, and / or plastics or ceramics can be utilized, with various consequences.

[0098] Figure 30 illustrates a perspective view of one exemplary embodiment of an enclosure 3000 for protecting a substrate from biofouling incorporating a wall structure having a plurality of layers, the wall structure incorporating a plurality of layers having the same, similar or different permeability, the same, similar or different materials, and / or the same, similar or different thicknesses for each layer. In another embodiment, the layers may be spaced apart at a minimum distance between each layer, or no distance, or a significant distance between each layer. Optionally, the first upper layer 3010 may be removable, and removal of the first upper layer (which may include "peeling off" or other type of connection segment 3015) exposes the intact second lower layer 3020, and removal of the second lower layer exposes the intact third lower layer (not shown), and so on, all surrounding the protected substrate. Optionally, the first upper layer may be removable, and the remaining lower layer(s) remain intact around the substrate, and then a replacement first upper layer may be positioned around the intact lower layer(s) and / or the substrate, such as when the first upper layer becomes sufficiently contaminated to justify removal and / or replacement. Alternatively, the plurality of upper and / or lower layers may include a plurality of sacrificial layers, each layer being removed when sufficiently contaminated to expose the underlying unused or semi-unused layer (i.e., still surrounding and protecting the substrate). In some embodiments, the lower layer(s) may remain in position around the substrate for a long period of time, even 1, 2, 3, 4 and / or 5 years or more, with periodic removal, replacement, and / or renewal of the outer layer(s) around the substrate and / or the lower layer(s) (i.e., removal of the contaminated layer and immediate and / or delayed replacement with a new upper layer). Such a system may have applications in salt water, fresh water, and / or brackish water, if desired.

[0099] In various embodiments, the enclosure design can 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 having sidewalls that surround the outer 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 can be assembled around the substrate and that can 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 with an open 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. Additionally, the enclosure walls can be relatively smooth or flat, or curved and / or continuous, or, if desired, can include very complex structures such as undulating surfaces, corrugated or accordion-like surfaces, folded, "wrinkled" or "crushed" surfaces, and / or other features that can dramatically increase the surface area and / or potentially alter the filtering ability of the enclosure walls.

[0100] In various embodiments, the enclosure can incorporate one or more walls that include a three-dimensional flexible filter cloth that contains fiber filaments and has 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 can include a textured polyester. Additionally, natural fiber materials such as 80×80 burlap can be useful as an enclosure material for protecting the substrate, even when the natural material decomposes relatively rapidly in an aqueous environment and the underlying decomposition process contributes to a significant measurable pH difference within the enclosure, and can be useful in various aqueous environments. If desired, various enclosure embodiments can 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 decompose after a period of time in an aqueous medium.

[0101] In various embodiments, the device of the present invention is desirably deployed to initiate the formation of a desired local aqueous environment (i.e., a "differentiated environment") that results in reduced biofouling on the protected substrate or article, which, when deployed, reduces biofouling protection, stops and / or reverses biofouling, and / or prevents the establishment of biofouling organisms, and / or promotes the formation of a desired anti-biofouling layer and / or biofilm on the substrate, i.e., induces the formation of a beneficial biofilm that results in reduced biofouling on the protected substrate or article. In various embodiments, this "differentiated environment" can be formed within minutes or hours of the 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 immersed and / or maintained in the aqueous environment. In various embodiments, the formation of a significant difference in the chemical composition of the water and / or other unique aspects of the differentiated environment can begin within one hour after the enclosure is placed in the aqueous environment (including 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 (including the formation of a complete differentiated environment and the formation of various fouling inhibition conditions that can be modified and / or supplemented when additional aspects of the differentiated environment are induced) can require the enclosure to be in a fixed position 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 differences in the chemical composition of water that can occur during these various periods can include dissolved oxygen, pH, total dissolved nitrogen, ammonium, ammonia nitrogen, nitrate, nitrite, orthophosphate, total dissolved phosphate, silica, salinity, temperature, turbidity, chlorophyll, etc., and their various concentrations can increase and / or decrease at different times, including the different concentrations of individual components at different durations of enclosure immersion.

[0102] In some cases, the devices of the present invention may decompose after a certain period and no longer provide the desired level of fouling prevention and / or environmental formation effects. In various embodiments, the amount of time until the enclosure loses its fouling prevention effect can vary based on many factors, including the specific aquatic environment, season, temperature, composition of the 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 fouling prevention and / or environmental formation effects and regain its fouling prevention / environmental formation effect(s) only when the conditions return to normal or somewhat desired criteria. As used herein, "service life" can mean the amount of time from the deployment of the enclosure until the level of macrofouling becomes a problem on the substrate, while "enclosure life" can mean the amount of time that the enclosure itself remains physically intact and effective around the substrate itself (which may be exceeded by the "service life" of the biocidal fouling protection provided by the enclosure). In various aspects of the present invention, one or both of the service life and / or enclosure life of the enclosure 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 years 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 a portion thereof can optionally be constructed of a degradable material that can include biodegradable, photodegradable, oxidative, and / or hydrolyzable materials, and preferably results in a decrease in molecular weight, a reduction in mass, and / or a reduced strength or durability of the enclosure or a portion thereof over time under certain conditions (and other potential effects). In various embodiments, continuous exposure of such materials to an aquatic environment can ultimately result in the detachment of the enclosure (or one or more of its layers) from the substrate, and / or environmentally friendly degradation of the enclosure and / or its various components. Such detachment can include detachment of the entire enclosure and / or detachment of different layers in a manner that is released in a time-release and / or fouling-dependent manner (i.e., weight-based, drag-based, and / or reduced wall flexibility).

[0104] Regardless of the type of material used, the enclosure can optionally be constructed such that the structure can be expanded three-dimensionally, radially, longitudinally, and / or in various combinations thereof. This type of construction preferably allows for positioning on an object in various configurations, which can include positioning, if desired, to reflect the contour of the surface of the object to which the enclosure wall is attached. In some embodiments, the enclosure can be formed in a mirror image shape of one or more surfaces of the substrate and generally be sized at least slightly larger 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 the use of artificial materials and / or biocidal toxins may be prohibited and / or not recommended, and may be deployed to protect a substrate in waters that require particular care, such as drinking water reservoirs and / or wildlife protection areas. In such cases, the enclosure preferably will not introduce significant potential to contaminate water and / or harm the local aquatic environment, even if the enclosure is to be detached from the substrate and / or associated support structure (as additional opening(s) in the detached structure may here prevent the development of the protected aquatic environment and its attendant benefits), and will provide protection to the underlying substrate for the desired period. In such cases, once the substrate no longer requires protection, or if the enclosure has become 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 material, and the substrate may be restored as necessary for fouling prevention.

[0106] Enclosure assembly In various embodiments, the enclosure can be constructed of a single piece or can include a plurality of modular components that can be assembled in various enclosure shapes. For example, the enclosure design can desirably include a plurality of wall structures, each wall structure being attached and / or assembled to one or more adjacent wall structures (if any) by stitching, weaving, surface fasteners, Velcro, etc., which can include coating and / or encapsulation of any seams and / or stitched / adhered areas. FIGS. 6A and 6B illustrate exemplary stitching techniques that can be particularly well-suited for use in constructing various enclosures of the present invention, and the stitching thread 630 that forms a seam 600 between a first fabric section 610 and an adjacent second fabric section 620 is such that the seam or the stitching thread of the folded edge of the overlapping fabric and / or the associated irregular surface is desirably not exposed to the external environment and thus desirably does not provide an external-facing surface that is susceptible to biofouling of the enclosure. (A slight gap formed along the outer surface of the enclosure may not be optimal but can be acceptable in various embodiments.) Alternatively, heat bonding, ultrasonic welding, and / or other energy-based joining techniques, adhesives or glues, and other connection techniques such as other stitching and / or two-dimensional weaving / knitting techniques can be utilized as needed. In other alternative embodiments, three-dimensional fabric forming techniques can be used to create a "tube" or bag of material for the enclosure that has no seams facing externally on the sides and / or has only one or more seams and / or openings at the top and / or bottom. In some particularly desirable embodiments, the attachment and / or adhesion of the various wall sections of the enclosure will preferably be achieved such that a certain level of flexibility is maintained within the attachment area.

[0107] In a similar manner, various embodiments of the enclosure will preferably incorporate a permeable and / or flexible attachment mechanism and / or enclosure such that a relatively hard, unbroken, and / or impermeable surface is preferably not presented to the outside of the surrounding aqueous environment by the enclosure. In many cases, biofouling entities may provide a "foothold" for subsequent colonization on adjacent flexible fabric sections such as those of the enclosures described herein, preferring a hard, unbroken surface for attachment and / or colonization. By reducing the potential for such "footholds", many of the disclosed enclosure designs can significantly improve the biofouling resistance of the various disclosed embodiments and / or the substrate protection they provide. In at least one embodiment, the enclosure may be specialized for a substrate fabricated as a single structure having no seams and / or impermeable wall sections.

[0108] In the case of hook-and-loop or "Velcro" fasteners, the adoption of such connection devices may be particularly well-suited for various enclosure embodiments in that such fasteners can be permeable to an aqueous medium in a manner similar to a permeable enclosure wall. Such design features allow liquid within the enclosure to elute through the fastener components and / or enclosure wall in a similar manner, thereby inhibiting fouling of the fastener surface as described herein. Alternatively, the connecting "flap" 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, impede, and / or prevent the effects of hydrostatic pressure from damaging the enclosure, various enclosure components, the protected substrate, and / or any connected objects and / or anchor systems. For example, many enclosures may desirably include a flexible fabric material (as compared to a non-flexible solid enclosure or enclosure wall) that can reduce, mitigate, and / or eliminate many of the effects of external water movement (i.e., flow, wave, and / or tidal action) on the enclosure and / or its components. In a similar manner, the presence of perforations and / or the permeability of the enclosure wall may desirably allow at least a portion of any hydrostatic pressure effects to desirably "pass through" the enclosure (resulting in a desired level of fluid exchange between the enclosure and the surrounding aqueous environment), reducing and / or mitigating the hydrostatic pressure acting on various portions of the enclosure and / or its support structure in terms of the other portions of the enclosure bending, flexing, and / or "flapping" in the moving water. Further, the use of flexible and compliant fabrics and / or other materials throughout much of the enclosure may desirably reduce the potential for work hardening and / or fatigue failure of the various enclosure components, improving the durability and functional life of the enclosure. Accordingly, at least one exemplary embodiment of the enclosure may include one or more wall components (or the overall enclosure design) that can move and / or flex in response to tidal, flow, and / or wave movement in the vicinity of the enclosure.

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

[0111] In many embodiments, the type and / or permeability level of the selected enclosure wall material(s) is a significant consideration in the design and placement of the enclosure and / or various enclosure components. At the 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, enabling the formation of a distinct environment that protects against biofouling. However, because various fouling pressures and / or other factors can potentially change and / or otherwise affect the permeability and / or porosity of a given enclosure wall material over time in an aqueous medium, in many cases it is important for the permeable material to continue to allow the desired level of water exchange to maintain the distinct environment, and desirably to avoid the occurrence of long-term anoxia within some enclosure embodiments. Given these concerns, it may be desirable to select a higher permeability level for the enclosure wall material so that clogging and / or closure of some of the pores of the material do not significantly affect the anti-fouling performance of the enclosure, even though the water exchange rate can decrease, increase, and / or remain the same at different times during the life of the enclosure.

[0112] Placement and Spacing In use, embodiments of the enclosure may desirably be applied around a substrate prior to immersion of the substrate in an aqueous medium. This includes protection of the object before it is first immersed in the aqueous medium (i.e., the “unused” immersion of the object into the aqueous environment), and protection of the previously immersed object after it has been removed from the aqueous medium and cleaned and / or descaled, where the enclosure is applied to the object prior to subsequent immersion. In other embodiments, the enclosure may be applied to an object already immersed in an aqueous environment, including objects that may have been previously immersed for an extended period of time and / or that already have a significant amount of biofouling thereon. Once the enclosure is applied to the object, the enclosure may be secured in several ways around one or more exposed surfaces of the substrate, thereby at least partially and / or completely isolating the aqueous environment within the enclosure from the surrounding aqueous environment to varying degrees. It should also be understood that in various embodiments, the enclosure may not “completely” surround the substrate, such as where the enclosure may have relatively large gaps and / or openings therethrough. In such cases, the enclosure may still be sufficiently “closed” to create the desired environmental changes within the enclosure to 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, sports, commercial, and military vessels such as jet skis, boats, ships, and marine vessels, civilian boats such as jet skis, boats, ships, and marine vessels, propulsion systems for boats, ships, and marine vessels, drive systems for boats, ships, and marine vessels, and their components such as stern drives, inboard drives, pod drives, jet drives, outboard drives, propellers, impellers, drive shafts, sterns and bow thrusters, brackets, rudders, bearings, etc., thrusters for boats, ships, and marine vessels such as housings, bow thrusters, and stern thrusters, inlets for boats, ships, and marine vessels such as cooling water inlets, HVAC water inlets, and propulsion system inlets, docks, slips, piles, piers, rafts, floating paint platforms, floating scaffolding platforms, and floating winch and towing equipment platforms, etc., ocean work support equipment, restraint and holding equipment such as anchors, ropes, chains, metal cables, mooring devices, synthetic fiber cables, and natural fiber cables, ocean instrumentation such as pH meters, dissolved oxygen meters, salinity meters, temperature meters, seismometers, and motion sensor instruments and associated arrays, etc., mooring equipment such as anchor chains, anchor cables, attachment chains, attachment cables, mooring chains, mooring cables, joints, floats, bollards, and associated attachments, etc., buoys such as marker buoys, channel marker buoys, inlet marker buoys, diver buoys, and depth indicator buoys, ocean piles such as wooden piles, metal piles, concrete dock piles, quay piles, pier piles, channel marker piles, and sub-surface structure piles, sub-sea structures such as breakwaters, oil and gas rig exploration and production structures, local government structures, commercial structures, and military structures, industrial filtration system equipment such as ocean filtration systems, membrane filters, water inlet filters, pipes and / or storage tanks, etc., ocean lifts and boat storage structures, irrigation water storage tanks and irrigation pipes and / or equipment, and / or any parts thereof, including water management systems and / or system components such as locks, dams, valves, sluices, and breakwaters.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. Not only does biofouling interfere with mechanisms, but it also occurs on the surface of living marine organisms when it is what is known as an epibenthic organism. Biofouling is also found in almost all situations where a water-based liquid is in contact with other materials. It has a significant industrial impact on marine cultures, membrane systems (e.g., membrane bioreactors and reverse osmosis spiral wound membranes), and the cooling water cycles of large-scale industrial equipment and power plants. Biofouling can also occur in oil pipelines carrying oil containing entrained water, particularly used oil, cutting oil, oil made water-soluble by emulsification, and hydraulic oil.

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

[0115] FIG. 7A illustrates one exemplary embodiment of a wound sheet cloth 700 incorporating an adhesive, a hook and loop material 710 (and / or stitches) along various portions of the cloth, which can desirably self-adhere to other cloth portions. As described herein, most of the cloth includes a perforated or permeable portion 720 (and in various embodiments, the fastener material itself can similarly include permeable and / or non-permeable portions). If desired, a material flap covering some other cloth portion is non-permeable and can protect the underlying structure.

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

[0117] If desired, the enclosure can be constructed using individual component segments that can be assembled into a three-dimensional (3D) structure. For example, the individual wall segments of the enclosure can be provided to be attached to each other in various configurations, including triangles, squares, and / or other polygons. If desired, the wall segments can be supported by a relatively rigid base frame, or these segments can be highly flexible and / or provided on rollers or other carriers and deployed to release each individual segment prior to assembly. In at least one alternative embodiment, an open enclosure frame or support can be provided, and an elongated sheet or enclosure wall material can be provided that can be wrapped around and / or laid over the frame segments (and applied to the frame in a manner similar to, for example, the "shipping packaging" of an object for shipping by a carrier).

[0118] Table 1 shows additional experimental results of the microfouling received by various enclosure designs used in a seawater environment to protect various substrates, together with control substrates (i.e., PVC pipes) in both coated and uncoated states (the coating contains biocidal eluting components). The enclosures incorporate various fabrics wrapped around the PVC pipes. After 240 days of immersion in seawater, the various enclosures were very successful in normally protecting the underlying PVC pipe substrates from fouling and also preventing the attachment of biofouling entities on / within the fabric structures of the enclosure walls themselves. These results were particularly impressive when compared to the amount and type of biofouling accumulated on the uncoated control pipes, as well as the significant amount of fouling attached to pairs of control PVC pipes (WB Pnt pipes and SB Pnt pipes) directly coated with biocide paints.

Table 1

[0119] Visual analysis of the above enclosures and associated protected substrates after 240 days of immersion revealed that all intact enclosures protected the substrates to a highly desirable level. Specifically, the outer surfaces of the substrates inside each enclosure were essentially uncontaminated, and most substrate surfaces had, if any, a light coating of easily removable deposits and / or residues, and some horizontal surfaces on the substrates had developed deeper pockets of deposits that were similarly easily removable. Additionally, the enclosures protecting each substrate had only their outer surfaces lightly contaminated, and each enclosure remained generally flexible despite the light fouling coating. Importantly, all intact enclosures prevented macrofouling on the underlying PVC substrates. WB10 and WBDUK sustained some level of damage and / or degradation to the enclosure walls that allowed some fouling to access the test sections within the enclosures. The solvent-based biocidal coated enclosures were still in good condition and had some edge fraying and edge cracks after 240 days of immersion in salt water. After long-term immersion, the water-based biocidal coated enclosures appeared to become progressively more fragile, with significant edge cracks and some holes in the wraps. In contrast, significant fouling occurred on both pipes coated with solvent and water-based coatings, although there was less fouling on the solvent-based coated pipes. The unprotected pipes were completely covered in some areas, up to depths exceeding the pipe diameter, under multiple fouling layers.

[0120] In the various examples of the above tests where the enclosure received unexpected openings, cracks, and / or was misaligned, the underlying substrate received very mild fouling on their outer surfaces in areas adjacent to the unexpected opening(s) and / or crack(s), and many of the "exposed" areas of the substrate had little or no fouling coating. In many cases, it was unclear when the various enclosure impairments occurred, but most of the "impaired" areas had the associated substrate exposed to the environment for at least one month or more. In these cases, it is thought that the initial placement of the enclosure caused and / or induced the formation of a "protective" biofilm layer on the surface of the substrate, and that after the integrity of the enclosure was breached and the substrate was directly exposed to the outside environment, this biofilm layer then protected the substrate from significant additional fouling.

[0121] Water exchange rate In various embodiments, an optimal, desired, and / or average “water exchange rate” can be determined to protect 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 designed and / or specified for a particular size, shape, and / or volume of enclosure and / or enclosure wall material that can be optimized to protect a particular type and / or shape of substrate material, can be designed and / or specified for a particular region or water depth, can depend on seasonal variations and / or temperature and / or tidal activity, and / or can vary due to water salinity, dissolved oxygen, nutrients, waste, water velocity, particular applications, and / or a number of other considerations. In various embodiments, the water exchange rate preferably creates 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 such that, without creating conditions that can damage the substrate unacceptably, it protects the underlying substrate surface from unacceptable levels of biofouling, e.g., to avoid the detrimental effects of anoxic conditions (i.e., in some embodiments, a dissolved oxygen level of approximately 0.5 mg / L or less) over a long period that can lead to unacceptable levels of substrate corrosion.

[0122] In various embodiments, the measured inflow of water in the "open" environment enables a change in the desired chemical composition of the water within the enclosure and the measured outflow of water from the enclosure (which may include the desired concentrations of metabolic waste within the enclosure and / or harmful, inhibitory, and / or toxic by-products), thereby allowing various harmful compounds, including "toxins" and / or inhibitory compounds of various known and / or unknown microorganisms, and / or other water chemical composition factors to elute through the enclosure wall and protect the outer surface and / or pores of the enclosure from excessive fouling (in some embodiments, the water flow conditions can create a "swarm" of such compounds that substantially surround part or all of the outer wall of the enclosure). In these embodiments, the presence of the enclosure can provide biofouling protection to both the substrate and the enclosure wall to varying degrees even in the absence of supplemental biocides or other fouling-protective toxins provided supplementally to the enclosure. For example, when various enclosure embodiments are arranged around a substrate to form the disclosed distinct environment, this distinct environment can also exhibit elevated concentrations of various metabolic wastes, and various processes and / or metabolic activities occurring within the enclosure can generate one or more substances (such as hydrogen sulfide or NH 3 -N, etc.) that are harmful to and / or have an adverse effect on fouling organisms. These harmful compounds can then increase in concentration and be present and / or elute through the enclosure wall, creating a localized "swarm" of harmful compounds that protect the outer wall of the enclosure to some extent from fouling organisms. However, once the harmful compounds leave the enclosure, many of them are rapidly diluted and / or decomposed by various natural processes that utilize the abundant dissolved oxygen outside the enclosure, thus removing 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 periodic, the enclosure can 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 amount of water within the enclosure per minute, exchanged between the protective enclosure and the surrounding aqueous environment, can provide a variety of anti-fouling and / or anti-corrosion effects on the protected substrate as described herein. However, exchange rates less than 0.5%, equal to 0.5%, 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 can optionally be determined as an average rate over a specific period such as per minute, per hour, per day, and / or per week, and during periods of water movement and / or non-movement such as during slack water and / or tidal ebb and flow. In other embodiments, a desired water exchange rate of up to 5% of the total amount of water within the enclosure per minute, exchanged between the protective enclosure and the surrounding aqueous environment, can provide a variety of anti-fouling and / or anti-corrosion effects on the protected substrate as described herein. However, exchange rates less than 5%, equal to 5%, 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 a water exchange rate of approximately 0.417% per minute (i.e., approximately 25% of the total enclosed or bounded volume per hour) of a sealed or bounded volume of water has been shown to provide the substrate with enhanced biofouling resistance. The enclosed or bounded amount of water within the exemplary enclosure can be calculated as the total enclosed or bounded volume of the enclosure minus the volume of the substrate within the enclosure. In other embodiments, the water exchange rate can be approximately 25% of the total enclosed or bounded volume of the enclosure per hour without considering 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 fouling prevention and / or corrosion protection, while in other embodiments, a desired water exchange rate within 0.1% to 1% of the total water volume per minute may be effective. In other embodiments, a water exchange rate of 1% to 5% of the total water volume may provide the desired level of fouling prevention and / or corrosion protection, while in other embodiments, a desired water exchange rate of 5% to 10% of the total water volume per minute may be effective. In other embodiments, the desired exchange rate may be in the range of 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 at 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 FIGS. 19 and Table 3 (below).

[0126] Also, when local water conditions provide a faster water flow over and / or away from the enclosure, and / or when the enclosure can be moved (i.e., by being attached to a moving and / or movable object), a lower permeability of the enclosure material allows a sufficient amount of liquid to permeate through a more permeable fabric by the faster water contacting and / or colliding with the enclosure wall(s) than would typically occur in a fibrous substrate and / or a relatively stationary body of water, thereby causing the water exchange rate desired to provide biofouling protection as described herein. In a similar manner, when local water conditions provide a slower water flow over and / or away from the enclosure, a higher permeability of the enclosure material allows a sufficient amount of liquid to permeate through a more permeable fabric by the slower water contacting and / or colliding with the enclosure wall(s) than would typically occur in a fibrous substrate and / or a relatively active body of water, thereby causing the water exchange rate desired to provide biofouling protection as described herein. [Table 2]

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

[0128] In other embodiments, the enclosure can be designed to have a specific surface area ratio and / or a range of surface area ratios, compared to the surface area of the enclosed substrate, which can vary widely depending on the enclosure design and / or the design and / or surface texture of the surface enclosure, and / or whether the substrate is fully or partially immersed, and / or other characteristics. For example, a given enclosure design and / or size can be utilized to protect a substantially smooth surface of the substrate and a more complex substrate surface (i.e., valves and / or propellers), and the surface area ratio can be approximately 1:1 or 1.1:1 for the enclosure / smooth substrate, or approximately 1:2 or greater for the enclosure / complex substrate. In a similar manner, a complex enclosure design can 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 expand in both directions to 1:2 to 2:1 or greater for various degrees of substrate and / or enclosure complexity. Generally, the enclosure design is expected to be at least slightly larger than the substrate (for a certain amount of water in the enclosure), and the surface features of the enclosure are expected to be somewhat less complex than the surface features of the substrate, so 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 smaller than the surface area of the substrate. This can occur when the substrate is partially immersed in the unit, regardless of whether 1%, 5%, 10%, 20%, 25%, 50%, 60%, 75%, 80%, 95%, 99% or less of the substrate is immersed. 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] Permeability One important aspect of the various enclosure embodiments disclosed herein is the incorporation of permeability elements, components, and / or structures into some and / or all of the enclosure components, which allows for some degree of bulk transport of water into and / or out of the enclosure in a controlled manner and / or speed. Desirably, the material(s) selected for the enclosure will include one or more walled structures having a level of permeability that allows for some level of "bulk fluid exchange" between the enclosure and the surrounding aqueous environment. This permeability is desirably optimized and / or suitable for the local environment in which the enclosure will be placed, although generally, enclosures with very high permeability enclosure materials can be somewhat ineffective at changing the chemical composition of the water within the enclosure and / or limiting or reducing biofouling on the protected article, so a low to medium level of permeability can be incorporated, while on the other hand, enclosures with very low or no permeability (or permeability that can become very low over time for many reasons, including fouling on and / or within the fiber surface) can lead to an unacceptable low level of liquid exchange through the fabric walls, which can 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. At various locations and / or environmental conditions (including various changes in seasonal and / or weather patterns), an increase or decrease in permeability or other enclosure design changes may be desired. In many cases, local environmental conditions (i.e., water flow, temperature, type of organism-flora, growth stage, salinity, available nutrients and / or oxygen, contaminants, etc.) and / or local water conditions / speeds (i.e., resulting from flow and / or tides) can affect the desired permeability and / or other design considerations. For example, a higher speed liquid impact on the enclosure can result in an increased water exchange rate for a given permeability of the material, which may require or suggest the use of a lower permeability material under 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 includes a material that is or becomes permeable in 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 inner / outer surface of the structure, and the structure or portion thereof has a water permeability of about 100 milliliters per second per square centimeter or less of the substrate when positioning the structure around the substrate or thereafter. In various embodiments, the water permeability of the structure can be achieved by forming a structure that allows water to permeate therethrough, for example, by manufacturing fibers to have a desired permeability. In some embodiments, the structure can be designed to become permeable over time when it is used. For example, otherwise permeable structures may initially include a coating that renders it substantially impermeable (this impermeability can be particularly useful for "jump starting" the desired low oxygen conditions within the enclosure immediately after initial placement), but when the coating is removed, corroded, or dissolved, the underlying permeability increases and / or becomes useful (this can help prevent the occurrence of undesirable persistent anoxic conditions within the enclosure after oxygenated water has permeated into the enclosure and low oxygen conditions have been reached).

[0131] In various embodiments, the optimal and / or desired permeability level of the enclosure fabric can approximate any of the fabric permeabilities identified in Table 3 (below), and in some embodiments, includes permeabilities in the range of 100 ml / sec / cm 2 ~0.01 ml / sec / sm 2 In various alternative embodiments, the fabric or other permeable material has a permeability of 0.06 ml / sec / cm 2 ~46.71 ml / sec / cm 2 or 0.07 ml / sec / cm 2 ~46.22 ml / sec / cm 2 or 0.08 ml / sec / cm 2 ~43.08 ml / sec / cm 2 or 0.11 ml / sec / cm 2~42.54 ml / sec / cm 2 or 0.13 ml / sec / cm 2 ~42.04 ml / sec / cm 2 or 0.18 ml / sec / cm 2 ~40.55 ml / sec / cm 2 or 0.19 ml / sec / cm 2 ~29.08 ml / sec / cm 2 or 0.32 ml / sec / cm 2 ~28.16 ml / sec / cm 2 or 0.48 ml / sec / cm 2 ~25.41 ml / sec / cm 2 or 0.50 ml / sec / cm 2 ~22.30 ml / sec / cm 2 or 0.77 ml / sec / cm 2 ~21.97 ml / sec / cm 2 or 0.79 ml / sec / cm 2 ~20.46 ml / sec / cm 2 or 0.83 ml / sec / cm 2 ~15.79 ml / sec / cm 2 or 0.90 ml / sec / cm 2 ~14.72 ml / sec / cm 2 or 1.05 ml / sec / cm 2 ~14.19 ml / sec / cm 2 or 1.08 ml / sec / cm 2 ~14.04 ml / sec / cm 2 or 1.11 ml / sec / cm 2 ~13.91 ml / sec / cm 2 or 1.65 ml / sec / cm 2 ~11.27 ml / sec / cm 2 or 2.09 ml / sec / cm 2 ~11.10 ml / sec / cm 2 or 2.25 ml / sec / cm 2 ~10.17 ml / sec / cm 2 or 2.29 ml / sec / cm 2 ~9.43 ml / sec / cm 2 or 2.36 ml / sec / cm 2 ~9.20 ml / sec / cm 2or 2.43 ml / sec / cm 2 ~9.02 ml / sec / cm 2 or 2.47 ml / sec / cm 2 ~8.24 ml / sec / cm 2 or 2.57 ml / sec / cm 2 ~8.16 ml / sec / cm 2 or 2.77 ml / sec / cm 2 ~8.11 ml / sec / cm 2 or 3.68 ml / sec / cm 2 ~6.04 ml / sec / cm 2 or 3.84 ml / sec / cm 2 ~5.99 ml / sec / cm 2 or 4.43 ml / sec / cm 2 ~5.40 ml / sec / cm 2 and / or 4.70 ml / sec / cm 2 ~4.77 ml / sec / cm 2 can be utilized within and / 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 differentiated environment and the open environment within the enclosure can be in the range of 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 20%, about 100% 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 of the volume.

[0133] As disclosed herein, when an enclosure is utilized to protect a substrate, 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 interrupted (disrupted, altered, etc.) to reduce and / or minimize substrate settlement, recruitment, and ultimately macrofouling. Once positioned around or inside the substrate (when protecting the inner surface of the substrate), 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 formed between the enclosure wall and the substrate can prevent some and / or all of the organisms from settling and / or colonizing on the substrate when the organisms are already located inside the enclosure and / or when the organisms ultimately pass through the enclosure. For example, when microscopic plankton and other conventional non-settling organisms and other settling organisms pass through the permeable fabric membrane of the enclosure, the various water conditions inside the enclosure can harm or damage some of the plankton, while other plankton that survive and remain active will avoid settling and / or colonizing on the substrate surface.

[0134] In various embodiments, an apparatus may be provided in which the permeability of a candidate material, such as a water column pressure testing apparatus commonly known to those skilled in the art, can be evaluated in a laboratory. For example, an exemplary test apparatus can use a pump to supply water from a reservoir to a water column of a specific height, and the test sample is inserted at the bottom of the column. Optionally, if desired, an overflow can be integrated into the design so that the height of the water in the column is preferably kept constant. The test sample size can be changed as needed. In one test setup, the water in the column over a 4-inch by 4-inch cloth coupon can be kept constant at a height of approximately 3 inches, providing a "head" pressure of 0.25 PSI. The permeability of each cloth coupon can then be calculated by measuring the volume per unit time per unit area exposed to the water column. If desired, the material can be tested under pre-wetted conditions, while in other tests, the material may be dried prior to the start of the test. In at least one exemplary embodiment, it was observed that when using dried samples for the permeability test, the water did not flow evenly through the test apparatus and accurate measurements could not be made.

Table 3

[0135] Tables 4A and 4B show the pre-immersion conditions in an aqueous environment (i.e., seawater) and the experimental permeability results after 23 days of immersion for various fabrics and coated fabrics. From Table 5B, it can be confirmed that the permeability of the jute fabric test samples was significantly lower than that of the spun polyester. However, both the jute fabric and the spun polyester functioned somewhat similarly to the anti-pollution fabric by at least partially excluding larger larval macro-organisms from the substrate environment. In various cases, the permeability of the fabric can decrease as a function of time related to surface fouling and / or other fabric degradation. One of the notable results of this test is that, due to the degradation and / or other properties of the jute fabric, as well as production issues that may be associated 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), the spun polyester may be a more preferred material than the jute fabric (which, although less preferred, may still be acceptable for various applications).

Table 4

Table 5

[0136] The water permeability of a material can be a function of a number of factors, including the composition of the material, the way 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 has been “pre-wetted” prior to testing and / or use in an aqueous environment. Further, since the permeability of a given material can change over time, there can be a range of acceptable and / or optimal water permeabilities even for a single material. In various aspects of the present invention, the water permeability of the enclosure can desirably be a sufficient initial minimum permeability to avoid the formation of certain anoxic conditions in a local (i.e., protected within the enclosure) aquatic environment, while in other embodiments, the permeability can be greater. In various aspects of the present invention, the enclosure material, when measured by the above test method, can have a water permeability 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 0.1 to about 25, about 0.1 to about 20, about 0.1 to about 10, about 0.1 to about 5, about 0.5 to about 100, about 0.5 to about 90, about 0.5 to about 80, about 0.5 to about 70, about 0.5 to about 60, about 0.5 to about 50, about 0.5 to about 40, about 0.5 to about 30, about 0.5 to about 25, about 0.5 to about 20, about 0.5 to about 10, about 0.5 to about 5, about 1 to about 100, about 1 to about 90, about 1 to about 80, about 1 to about 70, about 1 to about 60, about 1 to about 50, about 1 to about 40, about 1 to about 30, about 1 to about 25, about 1 to about 20, about 1 to about 10, or about 1 to about 5 (milliliters / second of water per square centimeter of substrate) either before use or achieved during use.

[0137] Dissolved oxygen In various embodiments, the placement of the enclosure within the aqueous medium around the substrate desirably "conditions" the dissolved oxygen, creating a dissolved oxygen differential between the inner and outer bodies of water of the enclosure, which desirably provides a significant improvement in preventing fouling of the protected article. In many cases, conditioning of the dissolved oxygen in the differentiated environment can involve the formation of a significantly lower dissolved oxygen level within the enclosure as compared to the external environment, and this dissolved oxygen level within the enclosure will vary to various degrees in response to the internal oxygen consumption and the external dissolved oxygen level. Additionally, a secondary gradient can also exist between the dissolved oxygen in 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 lower energy environment within the enclosure as compared to the external environment, and / or the absence of significant turbulent and / or vortical flow that could "mix" the water within the enclosure. These localized differential conditions can be caused by biological consumption of oxygen and / or nutrients, and / or other factors within the water column at the surface of the substrate or article and / or within the enclosure, which can lead to a further depleted "boundary layer" contributing to the absence of biofouling and / or the formation of a biofouling-preventing biofilm on the protected article.

[0138] Generally, 100% DO (“dissolved oxygen”) means that water contains as much dissolved oxygen molecules as possible in an equilibrium state. On the other hand, DO above 100% means that the water is “supersaturated” with oxygen (which can occur in seawater, often due to the effects of photosynthesis, air exchange, and / or temperature changes). In an equilibrium state, the proportion of each gas in water can approximate that in the atmosphere, but it rarely becomes the same. Therefore, in an equilibrium state, the percentage of oxygen in water (compared to other gases in water) can be equivalent to the percentage of oxygen in the atmosphere (compared to other gases in the atmosphere). However, the specific concentration of dissolved oxygen in a water body will typically vary based on other factors such as temperature, pressure, salinity, and the availability of photosynthesis and / or surface agitation. First, as temperature rises, the solubility of oxygen decreases. Thus, warmer water contains less dissolved oxygen at 100% saturation than colder water, and therefore, colder water can carry more oxygen. For example, at the sea surface and 4°C, 100% air-saturated water will hold 10.92 mg / L of dissolved oxygen. However, when the temperature rises to 21°C at room temperature, it is only 8.68 mg / L of DO at 100% air saturation. Second, dissolved oxygen increases as pressure increases. Deeper water can hold more dissolved oxygen than shallower water. Due to hydrostatic pressure, the gas saturation decreases by 10% for every 1-meter increase in depth. Thus, if the concentration of dissolved oxygen is at 100% air saturation at the surface, even if the same amount of oxygen available for biological demand still exists, it will be at only 70% air saturation 3 meters below the surface. Third, dissolved oxygen decreases exponentially as salt concentration increases. Thus, at the same pressure and temperature, saltwater holds approximately 20% less dissolved oxygen than freshwater. In addition, since the above factors can change (e.g., air or water temperature can vary throughout the day) and equilibrium may not yet be achieved, the dissolved oxygen at any given time may not be in equilibrium with the environment.Furthermore, wind and other agitation of the water can lead to water aeration beyond what is expected under ambient conditions, and local oxygen use and / or production by biological and / or other processes can continuously increase or decrease the amount of dissolved oxygen.

[0139] In various embodiments, once the enclosures described herein are placed around a substrate in an aqueous environment, the dissolved oxygen within the enclosures will desirably be utilized by various naturally occurring biological and / or other processes, whereby the localized dissolved oxygen levels within the enclosures begin to change relative to the dissolved oxygen levels in the water outside the enclosures. Because the diffusive transport of dissolved oxygen occurs very slowly in water, and because the solar energy that enters the enclosures to enable oxygen production via photosynthesis is typically little or not present at all, the main source of additional dissolved oxygen into the enclosures generally enters the enclosures through the bulk transport of the water outside the enclosures (which typically carries dissolved oxygen at a higher percentage) through the openings in the enclosure walls and other components. This additional dissolved oxygen is then utilized within the enclosures in a manner similar to that described above, and this cycle continues to repeat until the dissolved oxygen levels within the enclosures reach a stable level that generally exceeds anoxic levels but is significantly lower than the oxygen levels outside the enclosures.

[0140] Exemplary Dissolved Oxygen Measurement Protocol A dissolved oxygen (DO) sensing probe can be utilized to determine the dissolved oxygen content of a given region and the difference between two aqueous regions. For continuous monitoring, individual probes may be preferred over bundled sensor packages, primarily due in part to the way in which the DO values are determined from the measurements collected.

[0141] For various measurements, the DO sensor will collect readings (multiple possible), which can then be processed against readings from other sensor types to output a usable value. The DO concentration, 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 can be calibrated within acceptable tolerances, and the likelihood that any two sensors will maintain the same calibration is extremely low. This variability in calibration is one reason why individual probes are likely to produce better results than bundled sensors.

[0142] When groups of sensor readings are all processed with the same temperature, salinity, and pressure files, the resulting DO data is directly comparable. Conversely, each sensor bundle typically processes its raw data internally. The inherent variability of each probe in such cases can be combined when the data is calculated. This can 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 the sensor face) should be calibrated according to the manufacturer's specifications. All DO probes whose readings can be compared (along with temperature / salinity gauges) and which are to be placed in a water bucket or other container. The water should be bubbled or pumped to maintain a uniform water flow, and the probes should be evenly dispersed. The pressure sensors should be in close proximity. Once processed, the data collected in this way is likely to show any significant variability between the probes. This comparison should be done at the start and end of the sensor deployment.

[0144] In one exemplary method, a HOBO brand water quality monitoring probe is utilized. The usage method is as follows: (1) Install the sensor cap and calibration can be performed for all U26-001 DO loggers at both 100% and 0% according to the manufacturer's specifications. (If desired, startup details can be set at this point.) (2) Determine the appropriate logging interval. (3) For deployments over one day, sample every 0.5 hours. For shorter deployments, more frequent sampling may be desirable. (4) All loggers should be set to sample at the same interval to synchronize data and should be set to start at the same time and with the same data using the delay start function. (5) Consider performing the "bucket comparison" when setting the start time. (6) Start the pressure sensor (U20L water level logger), temperature / salinity sensor (U24-002-C conductivity logger), and all DO sensors (U26-001 dissolved oxygen logger) according to the manufacturer's specifications. (7) Prepare all sensors and test fixtures for deployment. (8) Offload sensor data immediately before deployment to eliminate irrelevant data. (9) Deploy all sensors. (10) It should be recalled that sensors deployed for open water readings (and sensors not properly protected from macrofouling) will need to be maintained to avoid data drift associated with macrofouling. (Depending on location and season, this can be on a daily basis, but typically in tropical and subtropical regions, once every few days is sufficient. The goal is to gently wipe the slime layer from the sensor surface, especially the logger, before macrofouling can form. Removing macrofouling from the sensor surface can damage the coating on optical sensors. If possible, it is very effective to alternately immerse two sensors in water on a bi-weekly schedule and gently wipe them before each redeployment. Then, these two data sets must be combined to create one continuous open water data set, and when the logger is swapped out, offload the data to a waterproof shuttle.)This will result in one "in-water" dataset and one "out-of-water" dataset from each swap-out, which means that the "in-water" data can be simply combined to create the desired dataset, and select two loggers with the closest calibration results from the "bucket test" for open water data. (11) Offload sensor data at appropriate intervals, which is sufficient for monthly data acquisition in the case of long-term deployment. (12) Use the dissolved oxygen assistant in HOBOware Pro or other suitable software to process the data. When combining large datasets in Excel, importing the comma-separated data assistant is very efficient. (13) If the experiment is carried out in its progress, or if the logger can be introduced for sensor surface replacement (every six months according to the manufacturer's specifications), perform a "bucket comparison" for calibration reliability and save the results for future reference.

[0145] Bucket comparison If desired, comparisons of the sensors can be made, which can be used to confirm the calibration reliability and save the results for future reference. Some of such comparison steps are: (1) Place the DO logger and conductivity logger in a 5-gallon plastic bucket filled halfway with water at least 15 minutes before the first sampling interval; (2) Hold the pressure sensor near the bucket during the test period; (3) Evenly disperse the sensors in the bucket; (4) Place an airstone at the center and middle of the water column to generate water movement during the test period; (5) Enable the test to be run for at least 24 hours; (6) Offload data from the logger using a waterproof shuttle (U-DTW-1) or a similar device according to the manufacturer's instructions; (7) Process the data using the dissolved oxygen assistant of HOBOware Pro or equivalent software, i.e., open the DO data set using HOBOware pro, select the process data using the dissolved oxygen assistant, specify the conductivity file to use, specify the pressure file to use, and once the data set is generated, export it to an Excel file for process and comparison, complete the process for all DO loggers, and combine the data from the Excel file to compare the calibrations).

[0146] Figures 8A and 8B graphically illustrate exemplary dissolved oxygen levels within various test enclosures compared to the dissolved oxygen levels of the surrounding aqueous environment (i.e., "open" readings). In these embodiments, the dissolved oxygen levels are consistently lower within the enclosures than the open readings for each of the enclosures, thereby creating an "environment different" 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 Figures 9 and 13).

[0147] Over a 24-hour period, the oxygen level outside the enclosure will typically vary in a diurnal-like pattern as shown in Figure 10A, with high levels of dissolved oxygen being generated during the day (the light regions of the graph) due to photosynthesis, and the dissolved oxygen level decreasing during the dark periods (the shaded regions of the graph). Inside the enclosure, the dissolved oxygen level over the same 24 hours will typically vary in a similar pattern to the level outside the enclosure because the amount of "dissolved oxygen replacement" entering the enclosure via bulk fluid transport depends on the outside dissolved oxygen level. Additionally, since the replacement dissolved oxygen enters the enclosure close to the walls of the enclosure, there is often limited bulk movement and / or mixing of water within the enclosure, typically creating a gradient of dissolved oxygen from higher to lower between the walls of the enclosure and the surface of the protected substrate.

[0148] As seen in Figures 10A and 10B, the enclosures described herein can desirably control, reduce, and / or "smooth" the dissolved oxygen level in a distinct aqueous environment (i.e., proximate to the protected substrate) compared to the DO level of water in the surrounding open aqueous environment. In many cases, 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), although the distinct DO level can exceed the DO level of the surrounding open aqueous environment in some embodiments and / or under some conditions. Additionally, the enclosures described herein desirably maintain a distinct DO level above the anoxic DO level, although periodic and / or intermittent distinct DO levels that fall within the anoxic range can be acceptable in various situations, including situations where the anoxic period is short enough to allow little or no anoxic corrosion of the substrate.

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

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

[0151] In various embodiments, the optimal and / or desired level of DO in the enclosure can be a DO content within at least an average of 20% or more, at least an average of 50% or more, at least an average of 70% or more, within a range of 20% to 100% average, within a range of 33% to 67% average, within a range of 50% to 90% average, or within a range of 70% to 80% average. Alternatively, the desired DO level in the enclosure can be a DO content that is at least an average of 10% less than the dissolved oxygen level in the water detected at a certain distance from the outside 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 regulation of dissolved oxygen in the enclosure will induce at least a 10% difference in dissolved oxygen between the distinct environment within the enclosure and the open aqueous environment outside the enclosure. In various embodiments, this difference can occur within a few hours / after the enclosure is placed in the aqueous medium, or can occur within 2 to 3 hours, 6 hours, 12 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, or even within 1 month after the enclosure is placed. In various alternative embodiments, a desired dissolved oxygen difference 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 occur.

[0153] Often, the dissolved oxygen level within a given enclosure will be depleted by biological and / or other processes, and maintaining the dissolved oxygen level within various enclosure designs potentially depends on the influx of dissolved oxygen from the surrounding aqueous environment through the walls of the enclosure (such DO levels being higher than the DO level within the enclosure), and this influx can also occur to some extent via diffusion through the wall structure itself, entrainment of bulk transfer of water through a permeable enclosure wall. The structures and methods described herein desirably provide sufficient water flow (and / or dissolved oxygen flow) within and / or through the structure to avoid the formation of an anoxic environment within the enclosure over a long period that could lead to corrosion of the metal surface, i.e., provide an enclosure with an appropriate level of "water exchange", but desirably also form a local aquatic environment and / or biofilm coating on the substrate that minimizes and / or prevents aquatic organisms from colonizing and / or thriving on the substrate. In particular, the devices of the present invention desirably provide a permeability level intended to maintain a DO level in a distinct aquatic environment (i.e., around the object to be protected) 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 DO level of the differentiated aquatic environment (i.e., containing the substrate to be protected) ranges from about 50% to about 110% DO. In this embodiment, it inhibits the ability of various organisms that contaminate the substrate (which is thought to substantially inhibit and / or prevent their ability to reproduce and / or form colonies), and does not "drop" to a DO level that can cause long-term anoxia and promote corrosion of the substrate (although periodic anoxic conditions for relatively short periods may have occurred and may have been acceptable for various reasons). In various embodiments, including those shown in FIGS. 10A - 10D, the presence of the enclosure can also mediate, "smooth" or "buffer" natural spikes and / or drops that can occur in the dissolved oxygen level of the surrounding aqueous environment, which can further prevent and / or inhibit aquatic organisms from colonizing and / or reproducing on the protected substrate.

[0155] In at least one alternative embodiment, the enclosure design can be permeable to one or more water chemical composition factors such as dissolved oxygen, while including wall materials that do not facilitate the transport / passage of one or more other factors, chemicals, and / or even water itself, allowing a sufficient level of oxygen (or other chemical factors) to permeate the enclosure to create some or all of the differences in the water chemical composition described herein. Such alternative designs may have some potential to effect various biofouling improvements disclosed herein.

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

[0157] FIG. 31 illustrates one exemplary embodiment of an aqueous flow mechanism of a supplemental pumping system 3100 for adding and / or removing aqueous liquid and / or other materials or substances to / from an enclosed environment within enclosure 3110. In this embodiment, the enclosure includes an outer 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 (in some embodiments, some or all of the walls of the enclosure that are non-permeable may be included). A pumping mechanism 3120 having a flow cavity or intake 3130 and a water intake pipe 3140 may be provided, and the pump further includes an outlet 3160 and an outlet pipe or flow cavity or flow path pipe 3170 that extends from the outlet of the pump through at least one wall of the enclosure and into / through the aqueous environment within the enclosure. In various embodiments, at least some of the flow cavity portions 3180 of the outlet pipe may extend a certain distance within the enclosure, and the outlet is potentially positioned proximally and / or distally from a 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 pump operation may be reversed to draw water from the enclosure so as to be discharged into the environment outside the enclosure. Alternatively, the pumping mechanism may be utilized to supply additional oxygen or other chemical constituents of water to the enclosed environment. If desired, some or all of the pumping mechanism and / or the flow cavity and / or the intake 3130 may be positioned within the enclosure, or alternatively within and / or through some portions of the enclosure walls, or if desired, may be positioned outside the enclosure. In another embodiment, the aqueous flow mechanism may be a propeller system, a petal system, a flow pipe, a flow waterway, or a flow tunnel that may be used in a similar manner to move water or to create the flow characteristics desired as a pumping system.

[0158] Instead of, and / or in addition to, reducing the dissolved oxygen level 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, which can include water chemistry factors that can significantly delay and / or prevent fouling of the protected substrate. For example, when oxygen is depleted within the enclosure, some species of bacteria that occur naturally within the enclosure will typically first change to the next best electron acceptor, which in seawater is nitrate. Denitrification occurs and the nitrate will be consumed rather rapidly. After reducing some other trace elements, these bacteria will ultimately change to reducing sulfate, resulting in the byproduct hydrogen sulfide (H 2 2S), which is chemically toxic to most biota and causes the characteristic "rotten egg" odor. Then, among other chemicals, this elevated level of hydrogen sulfide within the enclosure can inhibit fouling of the substrate in the desired manner, as described herein. Additionally, the hydrogen sulfide within the enclosure can also elute through the walls of the enclosure (i.e., with the bulk flow of water out of the enclosure) and potentially inhibit fouling growth within the pores of the enclosure and / or on the external surface.

[0159] In addition to forming localized conditions that inhibit fouling of the protected substrate contained within the enclosure, various embodiments of the enclosures described herein are also very environmentally friendly in that any toxic and / or uncomfortable conditions formed within the enclosure are rapidly neutralized outside the enclosure. For example, when 1 ml of fluid enters the enclosure through the opening, it can be assumed that approximately 1 ml of the enclosure fluid will be displaced outside the enclosure into the external environment. This displaced fluid will typically contain components that are toxic and / or uncomfortable for marine organisms (which preferably reduces and / or prevents fouling from adhering to the substrate within the enclosure). However, once outside the enclosure, these components are rapidly decomposed, oxidized, neutralized, metabolized, and / or diluted in the external aqueous environment by a variety of natural-occurring mechanisms and generally do not cause a lasting impact on the aquatic environment, even if in close proximity to the enclosure itself. This is highly preferable to existing antifouling 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 in the marine environment for decades.

[0160] In various alternative embodiments, the enclosure wall can incorporate additional biocide(s) or other chemical(s) or compound(s) that can 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) have a primary biocidal activity that is limited to the surface and / or within the pores of the enclosure fabric, and very low and / or non-existent levels of the biocide elute into and / or outside the enclosure. In such cases, the biocide preferably protects the enclosure from fouling, while the enclosure, in turn, protects the substrate from fouling.

[0161] A variety of test enclosures 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 immersed in seawater, and the dissolved oxygen levels in the aqueous environments inside and outside the enclosure were measured and tabulated. Figure 10A illustrates frequent sampling (i.e., every 15 minutes) of the dissolved oxygen levels over three days in spring / early summer, which exhibited the daily variation of dissolved oxygen inside and outside the enclosure (i.e., the bright and dark regions reflect day and night). In this figure, it can be seen that the dissolved oxygen level inside the enclosure typically lagged or "followed" (i.e., at a lower level) the dissolved oxygen level in the outer aqueous environment during the day and night sequence, and the DO inside the enclosure appeared "smoother" or more buffered than the DO in the outer environment. In contrast, Figure 10B illustrates similar sampling of the dissolved oxygen levels over three days in late summer / early fall, where the dissolved oxygen level inside the enclosure could often be equal to or greater than the level of the surrounding environment, and the enclosure provided "buffering" to the DO level. In all cases, the enclosure was successful in limiting and / or preventing biofouling of the protected substrate even when the relative levels of dissolved oxygen inside and / or outside the enclosure changed.

[0162] FIG. 11 illustrates an exemplary cross-sectional view of a substrate 1900 and an associated enclosure wall 1910 within an aqueous environment 1915. In this embodiment, the dissolved oxygen level 1920, indicated by the dashed line, may be equal to and / or equivalent to the DO of the surrounding aqueous environment at the boundary of the enclosure (however, in some embodiments, the dissolved oxygen level may be reduced to a measurable extent in the waterway through the wall 1910 of the enclosure). This DO level begins to gradually decrease in the enclosure liquid (following along the level line 1920) as a measurement sensor (not shown) moves further into the differentiated environment 1930 towards the substrate, and the DO level may desirably reach a lower and / or lowest DO level reading near the substrate surface 1940. In various embodiments, the change in the DO percentage from the liquid within the inner wall to the liquid near the substrate surface may be a change of only 1 or 2 percent, but in other embodiments, this DO change may be 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 different between the DO at the inner wall reading and the substrate surface reading, and can be very significant.

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

[0164] In some exemplary embodiments, the measure of one or more chemical composition characteristics of water may be "different" inside the enclosure compared to an equivalent measurement outside the enclosure (which may include measurements at a distance away from the enclosure, such as 1 or more inches, or 1, 2, 3, 5, 10, 20 feet or more from the outer wall of the enclosure, to account for potential leaching outside the enclosure). Such "differences" can include a difference of 0.1% or more between the inner / outer measurements, or a difference of 2% or more between the inner / outer measurements, or a difference of 5% or more between the inner / outer measurements, or a difference of 8% or more between the inner / outer measurements, or a difference of 10% or more between the inner / outer measurements, or 15% or more, or 25% or more, or 50% or more, or 100% or more. Additionally, such differences can be for multiple chemical factors with unequal differences, or can include an increase in one factor and a decrease in another factor. All such combinations of the described chemical composition factors of water are contemplated, including situations where some water chemical composition factors remain essentially the same for some factors while various differences can be observed for other factors.

[0165] Exemplary Water Chemical Composition Test Protocol When determining various water chemical composition parameter measurements, such as temperature, salinity, dissolved oxygen, and / or pH (among others), hand-cast sensors are easy to use and very accurate. 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), the readings between samples can be approximately the same without concern for calibration. If two or more probes are to be deployed simultaneously, it can be convenient to bundle them using Velcro strips or cable ties.

[0166] When working with sensors, the calibration of the handheld unit should be performed according to the manufacturer's specifications on a schedule. During calibration, reliability solutions can be used as spot checks for some sensors. It is important to check the handheld sensors before entering the field (battery life, reliability solutions, etc.). Prepare for readings by taking the unit out of the box, straightening the cable, bundling the sensors if using two or more, and marking the desired water depth on the cable (the standard for static immersion is 1 / 2 meter). Turn on the power of each handheld unit, place the probe(s) in the desired location, and confirm that the probe is at the desired depth. Wait for the probe to reach equilibrium; if it does not reach equilibrium, spot readings may not be sufficient to capture differences between samples, and continuous monitoring equipment may be required. Record the values and repeat each step of the process until all desired locations have been tested. Once the test is complete, rinse the probe and cable before replacing the protective cap / bottle and allow it to dry before returning the equipment to their respective boxes.

[0167] Exemplary Water Analysis Protocol In various embodiments, it may be desirable to quantify the difference in water inside and outside the fouling prevention enclosure, such as those described herein, including measured readings of dissolved oxygen (DO), pH, and / or salinity. In such cases, DO (YSI, ProODO), pH (YSI, Pro10), and salinity (YSI, Pro30) can be measured using a YSI single-parameter dropper sonde using the following method: (1) Calibrate the YSI sensor according to the 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 the measurement, (4) Record the DO, pH, or salinity value along with the location of the water, date, and time, (5) Record the water temperature value along with the location of the water, date, and time.

[0168] Exemplary Water Sample Collection for Chemical Composition Testing of Water In various embodiments, it may be desirable to collect water samples for analyzing the chemical composition of water, including (1) nutrient tests and (2) alkalinity tests. The water collection device can be a modified design of a standard 600 mL water collection device that uses the following method: (1) Use one water collection device for each water sample. The water collection device can be composed of a 1-foot long, 1-inch diameter PVC pipe for water collection, which is attached to a 3-foot long, 1-inch diameter PVC pipe for handling using a slip coupler. A plug composed of a rubber cork and a stainless steel eyebolt is suspended at the water collection end by a stainless steel ring at the opposite end of the water collection device using 50 lb test nylon fishing line. (2) Disinfect the water collection device before use. All device parts that come into contact with the water sample, the 1-inch diameter PVC pipe, the plug, and the fishing line are rinsed with filtered water, immersed in DI water for at least 12 hours, and then dried. The device handle and coupler should be rinsed with filtered water. (3) Disinfect all supplies that come into contact with the water sample during the test. The sampling bottle (250 mL), alkalinity analysis bottle (8 mL), funnel, and filtration syringe are rinsed with filtered water, immersed in DI water for at least 12 hours, and then dried. The nutrient analysis bottle (125 mL) is immersed in a 10% HCL solution for at least 12 hours, rinsed twice in DI water, and then dried. (4) To collect the water sample, immerse the water collection device 12 inches below the water surface or when the slip coupler is just above the water surface. Lift the stainless steel ring on the device handle to close the plug and collect the water sample. Before removing the device from the water, ensure that the plug is fully and tightly locked. Remove the device from the water. (5) Place the water collection device on top of a clean funnel and collection bottle. By releasing the stainless steel ring, carefully and slowly open the plug 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 the collected water sample may not be possible, and thus the following method can be used to filter the water sample and store it for up to 28 days: (1) Filter the collected water sample. For dissolved chemical and alkalinity tests, filter the water sample using a syringe polypropylene filter with a pore size of 0.45 μm (part number 6788 - 2504, Whatman). For nutrient tests, 125 mL of filtered water may be required. For alkalinity tests, 8 mL of filtered water may be required. (2) For storage up to 28 days, freeze the non - acidified filtered water sample at - 20°C. (Strickland and Parsons, 1972, Grasshoff et al., 1999, Venrick and Hayward, 1985). Store the water sample at - 20°C for nutrient analysis. Store the water sample at 4°C for alkalinity analysis.

[0170] In various embodiments, it may be desirable to quantify the difference in water inside and outside the fouling - prevention 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 can be used according to the following procedure for dissolved chemical tests using a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer:

[0171] For the analysis of TDN, ammonium, and nitrate + nitrite, the following method can be applied: (1) Obtain a filtered water sample, (2) Prepare a reference standard from RICCA ammonium (R0692500, RICCA Chemical Company), (3) Analyze the reference standard twice to calibrate the absorbance readings at 540 nm on a SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer. All standard absorbance values should be within 10% of the known concentration. (4) For the analysis of TDN, ammonium, and nitrate + nitrite, follow the manufacturer's method G-218-98 (SOP FIT-5008-TDN). Pass the filtered water sample through the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer and use a cadmium column to reduce nitrogen, and determine the absorbance at 540 nm of the pink azo dye formed by reacting the resulting nitrite with a diazo compound and N-(1-naphthyl)ethylenediamine dihydrochloride, (5) Record the absorbance value. The average analysis accuracy (RSD) is approximately 2%.

[0172] For the analysis of orthophosphate, the following method can 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) For the analysis of orthophosphate, follow the manufacturer's method SEAL analysis G-297-03. Pass the filtered water sample through the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer and determine the absorbance at 880 nm of the phospho-molybdenum blue complex formed when orthophosphate reacts with ascorbic acid, molybdate, and antimony, (5) Record the absorbance value. The average analysis accuracy (RSD) is approximately 1%.

[0173] For the analysis of TDP, the following method can 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) For TDP, follow the manufacturer's method G - 219 - 98 (SOP FIT - 5008 - TDP). Pass the filtered water sample through the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer and determine the absorbance at 880 nm of the phospho - molybdenum blue complex formed when orthophosphate reacts with ascorbic acid, molybdate, and antimony. (5) Record the absorbance value. The average of the analysis precision (RSD) is approximately 3%.

[0174] For the analysis of silica, the following method can 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) For silica, follow the manufacturer's method, SEAL Analysis G - 177 - 96. Pass the filtered water sample through the SEAL AA3 HR Continuous Segmented Flow AutoAnalyzer and 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 the absorbance values of the reference standard curve to determine the concentration of silica in the filtered water sample. The average of the analysis precision (RSD) is approximately 3%.

[0175] To determine the calcium carbonate level, 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 tests utilizing the Gran function according to the following method: (1) Obtain a filtered water sample, (2) Obtain a reference standard seawater solution (OSIL, UK), (3) Analyze the reference standard for calibration. Prepare a standard curve using the alkalinity values and the known concentrations of the analyzed reference standards. All concentrations should be within the 95% confidence interval, (4) For the alkalinity titration, follow the standard method (2320-B). Titrate the filtered water sample with 0.01N HCL using the Gran function, (5) The alkalinity is determined using the Gran function. The alkalinity (mg CaCO3 / L) is directly proportional to the amount of acid added during titration, (6) Record the value of the alkalinity.

[0176] For various tests, embodiments of enclosures using structures of different sizes and / or shapes, or different materials, were tested to determine whether the presence of the enclosure reduces, decreases, eliminates, inhibits, and / or prevents the establishment of macrofouling, which includes performing a visual comparison of the biofilms formed within the enclosure compared to open water, and comparing the water quality and chemical composition of the water within the enclosure to 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 the open sample at different points during sampling. Table 5B shows additional chemical measurements such as temperature, salinity, dissolved oxygen, and pH. The test results showed that ammonium was significantly higher inside the enclosure on the 14th day (6 / 22 / 18) and 30th day (7 / 9 / 18), and N+N was significantly higher inside the enclosure on the 1st day (6 / 9 / 18), 3rd day (6 / 11 / 19), 10th month (4 / 15 / 19), and 12th month (6 / 24 / 19). TDN and DON were significantly higher in the open sample on the 7th day, but switched and were higher inside the enclosure on the 14th and 30th days. Phosphate was significantly higher inside the enclosure on the 3rd, 7th, 14th, and 30th days, as well as the 10th and 12th months. Silica was significantly higher in the open sample on the 1st, 3rd, and 14th days, but was higher inside the enclosure on the 30th day. [Table 6] [Table 7]

[0177] The following various conclusions were revealed from the data: (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 until 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). The results of the biofilms from this experiment (observational) and the results of DNA from previous tests supported this hypothesis. The overall dissolved organic nitrogen (DON) inside the enclosure remained similar throughout the second half of the experiment, while the dissolved DON varied, which is likely due to the natural cycle of nitrogen in the harbor that was isolated or buffered by the enclosure. (2) Phosphate levels were higher inside the enclosure than in the open water, which is likely due to higher biological activity using phosphorus outside the enclosure and / or (3) silica levels were higher outside the enclosure until day 14, which is likely due to the higher activity and turnover of diatoms outside the enclosure that switched on day 30. The overall silica levels inside the enclosure were reasonably similar over time, while the open level silica varied. This variability likely indicates a cycle in the open water where silica was used by diatoms, i.e., a cycle isolated or buffered by the enclosure.

[0178] In another example, the chemical composition and water quality of water were observed in various enclosure embodiments. The purpose of this saltwater test was to examine the differences in the chemical composition of water between water inside enclosures of various sizes (diameters of 1, 2, and 4 feet) and the open water. Table 5C shows the results of a 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 all differed significantly between the enclosure and the open sample at different points during sampling. Table 5D shows additional chemical measurements such as temperature, salinity, dissolved oxygen, and pH.

Table 8

Table 9

[0179] The test results showed that dissolved oxygen and pH were significantly higher in the open water compared to the water area inside the enclosures for all sizes of enclosures (1, 2, and 4 feet in diameter). N+N, TDN, phosphate, and silica were all significantly different in the water area inside the enclosures compared to the open water. Alkalinity, N+N, TDN, and phosphate were all significantly higher inside the enclosures compared to the open water. This data shows a similar trend to other water chemistry composition tests in salt water. The increased water chemistry composition concentrations inside the enclosures when compared to the open water may indicate higher biological activity outside the enclosures by bacteria, cyanobacteria, and phytoplankton that utilize nutrients available for growth.

[0180] Furthermore, some of the results of these water chemistry investigations suggest that respiration or metabolism may have an effect that is higher than or exceeds photosynthesis within the enclosure structures for various enclosure embodiments. This effect may occur due to the reduced levels of dissolved oxygen or other water chemistry parameters caused by the enclosure structures. The difference in dissolved oxygen inside the enclosures may likely be related to the limitation of light inside the enclosures. The slight daily measurement variations, as seen in FIGS. 10A and 10B, may be related to the sampling timing (i.e., morning sampling vs. night sampling).

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

[0182] In one embodiment, the enclosure structure provides fouling prevention protection within its boundaries through the initial establishment of an environment rich in nitrification and denitrification. During this test, the data consistently shows higher ammonium in the water within the enclosure structure. As shown in Figure 12A, the initial nitrogen product of respiration is reduced nitrogen or ammonium. After four days of immersion, the internal environment becomes hypoxic, resulting in the formation of non-ionized ammonia nitrogen (NH3-N), which is toxic to marine life within the boundaries of the device. In addition to the production of NH3-N, nitrite (NO2) and other toxic reactive nitrogen molecules can also be produced within the boundaries filled with the medium of the enclosure structure. This effect appears to be enhanced as the exterior of the enclosure becomes progressively contaminated. Furthermore, the microbial biofilms formed within and on the surface of the enclosure device can contribute to the universal nitrification and denitrification pathways.

[0183] Test data often demonstrate that nitrate + nitrite (N+N) is higher in the water within the enclosure structure when compared to open water. This result may be related to the nitrification of ammonia that exceeds aerobic conditions. In some embodiments, dissolved oxygen is lower within the bag, but may not be low enough to inhibit nitrification, and the ammonium source may be derived from respiration. In some embodiments, dissolved oxygen is likely not low enough to enhance dissimilatory nitrate reduction to ammonium (DNRA) or ammonia formation from nitrate / nitrite, but an anoxic microenvironment (dissolved oxygen concentration in water less than 0.5 mg / L) that can enhance DNRA may be present within the bag. 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 Figure 12A.

[0184] Additionally, total dissolved nitrogen (TDN) was typically higher in the enclosed water compared to open water during the saltwater test. This result is consistent with high microbial respiration and dissolved nitrogen released from particles when the particles decompose. In some embodiments, the settlement of particles in the low-energy environment of the enclosure results in a source of dissolved nutrients settling into the enclosed water. This settlement of dead, dying, or decomposed particles at the bottom of the enclosure may, in some embodiments, explain the differences in chemical composition and water quality between the water in the enclosure and the open water. These decomposed particles or settlements may have consumed most of the dissolved oxygen within the enclosure structure.

[0185] Respiration is CO 2When released, this can, as a result, lower the pH and drive or reduce it to carbonate. By causing an increase in carbonic acid in seawater, the water will, as a result, become more acidic and thus have a lower pH measurement. Organisms respond rapidly to a decrease in dissolved oxygen, especially when the dissolved oxygen begins to reach levels of 3 mg / L or 2 mg / L. This difference in the water can cause organisms not to form shells or to form thinner shells. Furthermore, this difference can prevent organisms from settling or swimming and / or moving if the oxygen difference is too large.

[0186] The chemical composition of the carbonate also appears to be modified within the boundaries of the enclosure device, and the entrained water becomes more corrosive over time to calcium carbonate mineralization. To enable comparison of the open and enclosed waters sampled during the experiment, the NOAA CO2 Sys program, which evaluates changes in the chemical composition of carbonated water, can be used to generate a single integrated measurement, the saturation index of aragonite (Omega - Ω), for each water mass sampled at a particular point in time. The saturation index of aragonite (aragonite is a crystalline form of the calcium carbonate mineral), Ω, is a dimensionless number that indicates the supersaturation of calcium carbonate in seawater. Values greater than 1 indicate supersaturation (the size of aragonite will grow), and values less than 1 indicate undersaturation (aragonite will dissolve). Chemical oceanographers rely on the omega value to confirm the scale and trend of ocean acidification for a given ocean water mass. A decreasing trend in Ω is considered a threat of corrosivity 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 enabled a direct comparison of the water mass samples taken during 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 water area inside the enclosure structure and in the open water area. According to this theory, the nutrient limitation of carbon:nitrogen:phosphate ratio = 106:16:1 was investigated in seawater. Based on the increased concentration levels of ammonium (i.e., nitrogen) and phosphate within the water area inside the enclosure, in some embodiments, it was determined that there may be no nutrient limitation within the water area of the enclosure compared to the open water area.

[0188] In one embodiment, the enclosure can function as a substrate for bacterial colony formation and the settlement of macrofouling. Free exchange of dissolved oxygen, ammonia, nitrite, and nitrate can occur throughout the permeable enclosure. In one embodiment, the respiration of macrofoulers and / or bacterial biofilms can account for most of the uptake of oxygen and / or chemical nutrients across the permeable enclosure. The consumption of oxygen, nitrogen, phosphate, and other nutrients can occur by the biofilm when water passes or exchanges within the permeable enclosure. Bacterial biofilms can begin to participate in the OUR of the enclosure until the water area of the enclosure reaches a steady state with respect to the biofilm oxygen uptake rate (OUR). In one example, the steady state of nutrients in the water within the enclosure with respect to the biofilm can occur within less than 12 months, less than 6 months, less than 3 months, 1 - 60 days, within 1 - 30 days, or on the 58th day. Bacterial biofilms growing within or on the surface of the enclosure and macrofoulers of invertebrates growing on the outer surface of the enclosure are, in many embodiments, involved in establishing and maintaining a fixed film barrier, which can provide significant fouling prevention protection. In some embodiments, the film barrier can be a mechanism that prevents the occurrence of biofouling within a water compartment surrounded by a fabric structure.

[0189] Generally, non-ionized ammonia as NH3-N is very toxic to both aquatic and marine species at levels approaching 100 μg / L (ppb). The NH3-N concentration observed within the device after 7 days approached 20% of the toxicity level and could have been higher. Another potential contributor to toxicity within the device is nitrite (NO2), which is considered toxic at the 1 ppm level. During the saltwater experiment, the dissolved oxygen within the device did not decline to hypoxic levels (hypoxia occurs at dissolved O2 of less than 2 mg / L), but trended downward. Since the mechanism of action of this water chemistry does not depend on any specific microbial biofilm, it is also relevant for freshwater applications.

[0190] In another example, water chemistry and water quality freshwater samples were collected and analyzed from experiments at the University of Wisconsin at Milwaukee (UWM). Enclosure structures were deployed to protect valves and boats from fouling in the Great Lakes. After 1 month of immersion, water samples were collected within the enclosures 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 freshwater, and most of the chemicals were significantly different at two separate locations in the Great Lakes. Freshwater at the Marina (M) demonstrated significantly higher ammonium, TDN, and phosphate concentrations within the water inside the enclosure structure compared to the open water. The concentrations of nitrite, N+N, phosphate, and silica were all significantly higher in the water inside the enclosure compared to the open water of the UWM shoreline. These results could indicate higher biological activity outside the enclosure structure by bacteria, cyanobacteria, and phytoplankton that utilize the available nutrients for growth.

Table 10

Table 11

Table 12

[0191] Table 5F shows the results of one-month freshwater temperature, conductivity, dissolved oxygen, and pH for two locations in the Great Lakes, Marina (M) and the UWM breakwater (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 another freshwater experiment, water chemistry samples were analyzed for the entrained water inside the enclosure protecting the metal valve and for the open water areas at similar locations in the Great Lakes two months later. The test results for freshwater temperature, conductivity, dissolved oxygen (DO), pH, turbidity, and chlorophyll are presented in Table 6G. Dissolved oxygen, pH, and chlorophyll show significant differences between the water areas inside the enclosure and the open water areas. Dissolved oxygen and pH are lower in the local aquatic environment (the water area inside the enclosure) compared to the open water areas. Chlorophyll readings are significantly higher in the local aquatic environment compared to the open water areas. The differences in dissolved oxygen, pH, and chlorophyll can be explained based on the understanding that bacterial respiration in the aerobic environment is greater or more prominent than algal photosynthesis or nutrient uptake. Similar conclusions have been made for the freshwater tests as for the saltwater tests.

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

[0193] Water samples were collected from low-permeability enclosures, 154 - 30 nv, 153 - 40 nv, and 153 - 30 nv, high-permeability enclosures, 153 - 40 v and 154 - 40 v, and open water (control) using a core sampler of the chemical composition of water. 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 showed a greater difference in nutrient content compared to the open water samples. Generally, the nutrient content levels of the water were higher inside the enclosures compared to the open water. Additionally, the pH of the water inside the enclosures was observed compared to the pH of the open water. Depending on the enclosure design, substrate composition and / or other objectives, and various environmental and / or water conditions, the pH inside the enclosures can be higher than the pH of the open environment, or the water contained within the new enclosures can reflect a lower pH or a more acidic pH compared to the open water, which can constitute an important "difference" in the chemical composition of the water of the differentiated environment that contributes to the biofouling effect of some enclosure designs.

Table 14

[0194] Biofilm and / or film formation In various aspects of the present invention, the proper design and use of an enclosure as described herein can affect and / or induce the formation of biological coatings, layers, and / or biofilms on the surface of a substrate that effectively reduce and / or prevent the colonization of biofouling organisms on the substrate, and / or create a "different environment" within the enclosure. In some aspects of the present invention, this reduction and / or prevention can result from one or more local cues for settlement that discourage (e.g., reduce, minimize, or prevent) the settlement of larvae of biofouling organisms, which may include a lack of settlement on the substrate. On the other hand, in other aspects of the present invention, the reduction and / or prevention can result from the absence of one or more positive cues for settlement that promote the settlement of larvae of biofouling organisms, which can similarly 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 present invention, the enclosure can promote the growth of microorganisms that create one or more local cues for settlement that discourage the settlement of larvae of biofouling organisms within the distinct aquatic environment formed by the enclosure. In a further aspect of the present invention, the enclosure can promote the growth of microorganisms that create one or more local cues for settlement that discourage the settlement of larvae of biofouling organisms on and / or within the enclosure material itself. Thus, in these aspects of the present invention, larvae of biofouling organisms may not be able to or may be less likely to settle or attach to an immersed substrate or substrate portion(s) protected by the enclosure.

[0195] In various embodiments, the biofilm can be on a protected substrate and can be formed on the outside and / or inside of the enclosure. The biofilm at each location can differ based on the amount of bacteria, cyanobacteria, diatoms, various bacterial phyla, diversity, thickness, and integrity, as well as by other metrics.

[0196] Figure 14 illustrates one exemplary "standard" progression or colonization sequence that typically leads to the establishment of a fouling community on a substrate immersed in an aqueous medium such as seawater, saltwater, and / or freshwater. In this sequence, the immersion of the substrate into the aqueous medium immediately initiates the physical process of polymer adsorption, followed by the rapid landing, attachment, and colony formation of prokaryotic cells and bacteria on any surface within the marine environment. In some cases, subsequent microbial biofilm formation can then enhance the attachment of algal spores, protozoa, barnacle cyprids, and marine fungi, followed by the settlement of larvae of other marine invertebrates and macroalgae. In other cases, however, macrofoulers can settle without a biofilm, and still 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 explains the initial steps prior to colonization. Within the first minute, van der Waals interactions coat the immersed surface with a conditioning film of organic polymers. In the next 24 hours, this layer enables the process of bacterial attachment to occur, and both diatoms and bacteria (e.g., Vibrio alginolyticus, Pseudomonas putrefaciens) attach to initiate biofilm formation. By the end of the first week, the abundance of nutrients and ease of attachment to the biofilm allow secondary colonizers, spores of macroalgae (e.g., Enteromorpha intestinalis, Ulothrix) and protozoa (e.g., Vorticella, Zoothamnium sp.), to attach themselves. Within two to three weeks, macrofoulers, which are tertiary colonizers, 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 can change. For example, the biological colonization sequence on the substrate can be interrupted (disrupted, altered, etc.) to reduce and / or minimize the establishment, recruitment, and eventual macrofouling of the protected substrate. Once positioned around the substrate, the permeable protective fabric wall of the enclosure preferably filters and / or impedes the passage of various micro- and / or macro-organisms into the enclosure and can 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 bar graphs from the left end) and substrates within various embodiments of enclosures in seawater (six bar graphs from the right end), and Table 7 (below) contains the underlying data illustrated in FIG. 15. The bacterial biofilms formed on substrates or other articles protected by enclosures were significantly different from any natural biofilms formed on substrates or other objects in the open water or other aqueous environments adjacent to the protected articles. In various embodiments, the proper design and operation of the enclosures will preferably induce and / or enhance the growth and replication of a particular combination of microorganisms, many of which are typically found at different (i.e., often relatively low) levels in natural environments, and these combinations of microorganisms can have the ability to enhance a particular "recruitment and establishment" behavior to other organisms and identify the surface of the substrate as uncomfortable and / or "less desirable" (and signal this fact through various means).

[0200] DNA analysis confirmed that the surface biofilms formed on the PVC and bronze substrates inside various protected enclosure embodiments were significantly different from those formed on similar substrates outside the enclosures, which also applied to the biofilm-forming communities present within the enclosures and the biofilms formed on / within the inner wall surfaces of the enclosures. For example, the biofilms that appeared on the PVC and bronze article coupons in open water were thicker and more diverse compared to the biofilms that appeared on the PVC and bronze article coupons protected by the enclosures of the present invention. Additionally, macrofouling was observed on the articles in open water, while macrofouling was hardly or not at all present on the substrates protected by the enclosures. In some embodiments, the biofilms on the enclosed substrates were less diverse than the open biofilms and were accompanied by different amounts of diatoms, bacteria, cyanobacteria, and different bacterial phylum distributions. Additionally, the dominant bacterial phylum and bacterial distribution within each enclosure (and / or on each substrate) were significantly different for each enclosure design. For example, as best seen in FIG. 15 and supported by the data in Table 7, the PVC substrate within the spun poly enclosure (the three bar graphs from the right end) had Proteobacteria (the large group at the top of the bar graph) and Bacteroidetes (the second largest grouping towards the bottom of the bar graph) as dominant. In contrast, the bronze substrate within the spun poly enclosure (bar graphs 6 - 9) had Proteobacteria as dominant and the much smaller remaining portion had Bacteroidetes as dominant. This distribution map of the dominant bacterial phylum of the biofilms is for the open bronze bar graphs (columns 1 - 3), open PVC bar graphs (columns 4 - 6), enclosed bronze bar graphs (columns 7 - 9), and enclosed PVC bar graphs (columns 10 - 12). Additionally, the "integrity" of the biofilms on the enclosed substrates was different from the open samples in that the biofilms on some of the enclosed substrates appeared to be easier to remove and / or wash from the substrate surface compared to the open substrates.

Table 15

[0201] In some experiments, various substrates were immersed in an aqueous environment (i.e., natural seawater), and some substrates were protected by an enclosure design such as those described herein during a 3-week immersion period, at which point the substrates were removed from the seawater and the enclosures and the resulting biofilms on the substrate surfaces (formed on these substrates during that time) were subjected to DNA analysis. Visual comparison between the bronze substrates protected by the enclosures, as compared to the unprotected (i.e., open) bronze substrates, showed a marked reduction in fouling organisms on the protected substrates. Further, it was demonstrated that the biofilms formed on the open bar graphs (i.e., unprotected PVC and bronze) were significantly thicker than the biofilms 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 Verrucomicrobia 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 within the artificial "differentiated" environment created by the novel enclosures is unique and represents a significantly different (and potentially disadvantageous) colonization cue as compared to those presented by the normal colonization cues of the biofilm layers naturally formed in open aquatic environments, thereby reducing the opportunity for colonization and / or colony formation of substrates by micro- and / or macro-fouling agents even in the absence of the enclosures (i.e., after the enclosures have been permanently and / or temporarily removed).

[0202] In another experimental test, a series of transparent glass substrates were immersed in an aqueous environment and analyzed to determine the thickness and type of biofilm / fouling formed on the substrates protected by a novel enclosure design, such as those described herein, and unprotected substrates, over periods of 30 days, 8 months, and 12 months. These test results concluded that no macrofouling settlement occurred on the slides inside the novel enclosures throughout the 30-day test. In contrast, slides placed in open water continued to accumulate macrofouling until day 30. The macrofouling on the open slides consisted of hydroids, encrusting and branched bryozoans, barnacles, tube worms, and sponges, and a significantly higher settlement on the open slides began on day 14.

[0203] Regarding the biofilms on various substrates, the unique biofilm on the slides from inside the protective enclosure was determined to be so thin as not to be easily visible, and the presence of the biofilm was indicated by small adherent clumps of sediment. The appearance of the biofilm on these protected slides changed little from day 1 to day 30. Conversely, the open slide biofilms after 30 days of immersion in salt water underwent significant changes during the course of the experiment. On day 1, the biofilm was very light and similar to a distinct biofilm. However, by day 3, ciliates (predatory ciliates that eat biofilm) were dominant in the open 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 eat sessile biofilm organisms. These unprotected biofilms were thicker and more developed on day 14, with filamentous algae accumulating. Additionally, the dissolved oxygen levels were significantly higher in the open water than inside the novel enclosures on days 1, 7, and 14. Furthermore, the liquid pH was significantly higher in the open water than inside the novel enclosures after day 14.

[0204] After 1 year of immersion in salt water, glass substrates protected with cloth biofouling prevention enclosures were examined for biofouling. After 12 months of immersion, no large or small biofouling or biofouling was present on the protected glass substrates, but a biofilm was formed on the glass substrates protected by the cloth enclosures. This 12-month biofilm ranged from a patchy, uneven, discontinuous thin layer on some substrates to a continuous thin film layer that completely extended over the entire surface on other substrates. These 12-month biofilm structures were more developed and complex compared to the biofilm on the glass substrates after 30 days, but the biofilm on the unprotected glass substrates after 30 days was exponentially more developed, complex, and thicker than the biofilm on the protected glass substrates after 12 months. Except for a few collected (but not established) central diatoms, no cyanobacteria or diatoms were present in the biofilm on the protected glass substrates after 12 months. The structure of the 12-month biofilm on the protected glass substrates contained silt trapped in extracellular polymeric substances (EPS), and a few glass substrates contained low-encrusting tube worms (spirorbid and Hydroides sp.).

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

[0206] Once a biofilm or other layer is present or established, regardless of the presence of cues for local attachment, these cues can cause the enclosure to remain within / 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 a cue for local attachment becomes associated with or present on the substrate, the enclosure can be removed and / or damaged, and at least a portion of the cue for local attachment persists on the substrate to provide a continuous signal to discourage and / or not promote the attachment of macrofouling organisms. As an example, this preventative effect of the cue for local attachment can remain on the hull of a boat after the enclosure is removed (and / or damaged) and continue to discourage attachment. This discouragement of attachment can 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 can be resistant to removal and thus provide continued protection against movable and / or mobile immersed and / or partially immersed surfaces and / or items, including items used to generate propulsion, such as propeller blades and / or shafts. Thus, the enclosures and processes of the present disclosure can enable "seeding" of substrates against biofouling, which can persist for a while due to the lasting effect of local attachment cues (LSCs).

[0207] In various embodiments, it is proposed that changes in the chemical composition of water, including all measured parameters, may at least in part be due to the accumulation of biofouling organisms on the outer surface, inner surface, or within the fabric of the enclosure structure. In one embodiment, an external biofilm developed on the outer surface of the enclosure structure accumulated and became prominent by day 13 and matured and developed an organized structure by day 30. At these time points (day 13 and day 30), dissolved oxygen and pH decreased significantly inside the enclosure structure. In some exemplary embodiments, dissolved oxygen and pH may be correlated together because 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 carbonic acid in the water results in more acidic conditions and thus decreases the pH of the water.

[0208] In some embodiments, the biofilm components can be used as a cue for appropriate settlement sites. Additionally, the receptors for bacterial cues for invertebrate larvae can be unique to each organism. For many organisms, larval settlement occurs in response to the surface biofilm. The difference between the biofilm on the substrate surface and the biofilm on the enclosure surface can potentially cause an organism to settle on one biofilm and not on the other. Preferably, settlement 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 can act as a "biofilter" and / or utilize or consume nutrients (i.e., oxygen, nitrogen, carbon, phosphate, etc.), thus allowing some or all of the nutrients to pass or migrate into the water inside the enclosure structure, which can demonstrate where the chemical composition data of the water indicates that more respiration or nutrient uptake occurs in the open water as compared to the enclosed water within the structure. These two communities, the bacterial biofilm growing within the fabric and the macrofouling of invertebrates growing on the outer surface of the structure, can be involved in the establishment and maintenance of a fixed film barrier that provides fouling prevention protection, which is at least one mechanism for preventing biofouling within the compartment enclosed by the structure.

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

[0211] Optional biocide coating and / or integration In some exemplary embodiments, the disclosed enclosures may not include and / or may not require the use of supplemental biocides and / or fouling prevention agents(s) for the enclosures to provide suitable biofouling protection to the enclosure material and / or substrate, which may be a fouling pressure such that an unprotected cloth is free of macrofouling and / or when an uncoated enclosure may be sufficient to provide protection to the contained substrate for a desired period, which may include the use of an unprotected cloth enclosure during a certain immersion period. Similarly, the disclosed enclosures may use various enclosure designs, including tightly wound enclosures, bag enclosure embodiments, and / or "skirt" enclosure embodiments that provide such protection to varying degrees, to provide protection to the substrate against destructive and / or invasive organisms such as fouling organisms that bore into wood (i.e., shipworms or "teredo worms" and associated bacteria).

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

[0213] Generally, a biocide or other chemical substance, compound and / or microorganism having the ability to exert a destructive, inhibitory, detoxifying, and / or controlling effect on any unwanted or undesired organism by chemical or biological means can optionally be incorporated within and / or onto some part(s) of the material, such as during the manufacture of the material or material component, or the biocide etc. can be introduced into the material after manufacture. Desirably, one or more biocides within / on the material will inhibit and / or prevent the colonization of aquatic organisms on the outer surface and / or within the openings in the enclosure, and incapacitate, disable, impede, and / or weaken biofouling organisms that attempt to penetrate or are sufficiently small to repel from penetrating normally through the openings in the enclosure, such that the biofouling organisms are less able to reproduce in the artificial or synthetic local aquatic environment between the structure and the substrate. In various embodiments, the enclosure desirably incorporates a material that maintains sufficient strength and / or integrity to enable (and / or is desired to enable the formation of) artificial local aquatic environment or synthetic local aqueous environment for the protection and / or inhibition of biofouling for a service life of about 3 to 7 days or more, 7 to 15 days or more, 3 to 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 materials coated, painted, and / or impregnated with a biocide coating, which preferably adheres and / or penetrates to the desired depth in the material (including a surface coating of the material on only one side of the fabric, a coating that can penetrate 1% to 99% of the paths through the fabric, and a coating that can penetrate completely through the fabric and coat some or all of the opposite part of the fabric). Preferably, 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 attempting to enter a distinct aqueous environment through openings in the material (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 a three-dimensional "entry path" into the enclosure (i.e., when microorganisms pass through the openings and / or pores of the material) will preferably provide a larger surface area and prove to be more effective than the standard two-dimensional paint biocide coatings (i.e., hard planar coatings) utilized on the rigid immersed surfaces for today's marine applications. In various aspects, particularly when the fabric substrate material is highly fibrillated and / or ciliated, the coating of such a material may preferably provide a higher "functional surface area" of the fabric for the biocide coating to adhere to, which preferably improves the potential for anti-biofouling effectiveness because when organisms pass through the fabric, they are more likely to be located near and / or in contact with these small fibers (and the biocide paint, coating, or additive present thereon or therein).

[0215] In various alternative embodiments, the enclosure may incorporate a material that is coated, painted, and / or impregnated with a biocide 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 to some extent within the pores of the fabric), which may penetrate up to 5%, up to 10%, up to 15%, up to 20%, up to 25%, up to 30%, up to 35%, up to 40%, up to 45%, up to 50%, up to 55%, up to 60%, up to 65%, up to 70%, up to 75%, up to 80%, up to 85%, up to 90%, up to 95%, up to 99% of the pores of the fabric, and / or extend out of the pores to the opposing surface of the fabric, and may include a coating on one surface of the fabric that penetrates up to 100% of the pore paths through the fabric.

[0216] In various embodiments, the incorporation of additional biocidal coatings or other coatings / additives of some embodiments also desirably inhibits and / or prevents biofouling organisms and / or other harmful agents from colonizing the flexible fabric and / or the perforations therein for a period of time after immersion, thereby desirably improving the durability and functional life of the enclosure and / or its components in terms of maintaining the flexible perforated nature of the enclosure wall and the attendant advantages. When the biocide is retained primarily in proximity to the fabric substrate (i.e., when the biocide elution level is very low or there is no elution), the biocide will desirably significantly inhibit biofouling of the enclosure wall, while the presence of the enclosure and the "distinguished aqueous environment" formed therein will reduce and / or inhibit biofouling of the protected substrate. In various exemplary embodiments, the biocide has a very low and / or non-detectable level (i.e., less than 30 ng / L) in the water within the distinguished aqueous environment and / or in the open water adjacent to the enclosure, and still can leave a high effect of protecting the enclosure and / or the substrate from biofouling. As shown in FIG. 28A, the biocide release rate from the enclosure is detected to be 0.2 to 2 ppm or less in artificial seawater over 7 days, and the low local concentration (i.e., biocide release rate) is detected to be 0.2 to 2 ppm or less in artificial seawater over 7 days and was effective in protecting the enclosure from biofouling.

[0217] A wide variety of supplemental coatings incorporating various biocides and / or other dispensing and / or eluting materials can be incorporated into a given enclosure design to provide various anti-fouling advantages. For example, FIGS. 28B and 28C illustrate the biocide release rates of various coatings and / or enclosure designs, including coatings that release econea and / or pyrithione in various amounts and / or at various timings, with embodiments having initially high release rates that decrease significantly only after several days and / or weeks after immersion, as well as other embodiments having initially low release rates that increase with immersion time.

[0218] In at least one exemplary embodiment, the enclosure material can include a spun polyester fabric having a surface and / or subsurface coating of a commercially available biocide coating that includes a water-based and / or solvent-based coating containing a registered biocide, and the coating can be 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 or without vacuum assistance). The coating of the material can be achieved with a coating on one or both sides of the material, a single-sided coating on the inward-facing side of the material, but a single-sided coating on the outward-facing side of the material (i.e., away from the substrate and toward the open aqueous environment) has demonstrated a significant level of effect while minimizing biocide content and cost and maintaining advantageous flexibility. Water-based ("WB") biocidal coatings are mainly discussed in various embodiments herein, but solvent-based ("SB") biocidal coatings can 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 coating can have the additional advantage of enabling the incorporation of visible patterns and / or logos within and / or on the enclosure walls, which can 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 use area and / or conditions (i.e., "saltwater immersion only" or "use only in Jacksonville Harbor" or "use only in summer"). If desired, various indicators can be incorporated to identify the age and / or conditions of use of the enclosure, including printing the date of an "expiration date" on the outside of the enclosure. If desired, a visible pattern can be printed using the biocide coating itself, which can incorporate additional ink and / or dyes in the coating mixture, or additional logos, etc., can be printed using separate additives.

[0220] In various embodiments, the biocide coating or paint can desirably be applied to the material in an amount in the range of from 220 grams per square meter to 235 grams per square meter, although applications less than 220 grams per square meter including 100 grams per square meter, and applications greater than 235 grams per square meter including 300 grams per square meter and above, exhibit significant potential. In various alternative embodiments, the coating mixture can include one or more biocides in various percentage weights of the mixture, including biocides of 10 weight percent or less such as 2%, 5%, and / or 7% of the mixture, or greater amounts of biocides including 10 weight percent, 20 weight percent, 30 weight percent, 40 weight percent, 50 weight percent, and / or more of the coating mixture, and virtually any combination thereof (i.e., ranges including 2% to 10% and / or 5% to 50%, etc.). Where the enclosure design can 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] FIG. 29 illustrates a cross-sectional view of an exemplary permeable fabric 2900, with various pore openings 2910 and simplified passages 2920 extending from a front face 2930 to a rear face 2940 of the fabric 2900. A coating material 2950 containing a biocide or other debilitating substance is also shown, with some portions of this coating material extending into the pore openings 2910 and / or passages 2920 of the fabric 2900 at a distance “D” of at least some extent from the front face 2930. In various embodiments, the coating material will desirably penetrate the fabric of the material and / or the openings / pores of the fabric wall at an average distance “D” of some extent (i.e., a depth of penetration into the fabric of 3%, 5%, 10%, 15%, 20%, 25%, 50%, 75%, or more, see FIG. 29). Desirably, a “more rigid” coating material is applied in a manner that allows the fabric to be bent and / or shaped to some extent and is in a drier configuration than the fabric to which it is applied in many cases (i.e., the coating will desirably not “rigidify” the fabric to an undesirable extent, visibly, or severely), enabling the fabric to be formed into the desired enclosure shape and / or wrapped around a structure and / or formed into a flexible bag and / or container (if desired). When a bag or similar enclosure (i.e., a closable shape) is provided, the coating can desirably be applied onto / into the item after its manufacture, which can include coating and / or encapsulating any seams and / or stitched / adhered 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 a biocide coating or paint, the material and / or enclosure can be allowed to undergo a storage process and / or air dry for a desired period (less than 2 minutes in some commercial applications or up to 1 hour or more in other embodiments), or can be forced dried using a gas, oil, or electric heating element. The material and / or enclosure can then be used as described herein.

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

[0224] Other methods of inserting and / or applying biocides or antifouling agents are contemplated, such as the use of spray coating, known to those skilled in the coating art. Additionally, the enclosure need not contain individual fibrous elements, but instead may be made of a perforated and / or flexible sheet containing biocides embedded therein and / or coated on the material. To provide a securing mechanism, the enclosure may include fastening elements such as, but not limited to, surface fasteners such as VELCRO®, snaps, buttons, clasps, clips, buttons, adhesive strips, or zippers. Optionally, the enclosure may preferably include a plurality of wall structures, each wall structure being attached, by stitching, weaving, etc., to one or more adjacent wall structures (if any), which may include coating and / or encapsulation of any seams and / or stitched / adhered areas under one or more coating layers to form a modular enclosure. Optionally, the 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 preferably includes anti-biofouling properties that are attached to and / or embedded within the suture and / or fiber (i.e., various elements of the fibrous substrate) to inhibit and / or prevent biofouling of the enclosure. In a preferred embodiment, the anti-biofouling agent is a biocide coating that includes Econea™ (tralopyril, commercially available from Janssen Pharmaceutical NV of Belgium) and / or zinc omadine (i.e., pyrithione), although other currently available and / or future developed anti-biofouling agents known to those skilled in the art, such as zinc, copper, or derivatives thereof, may be used. Additionally, fouling prevention compounds derived from microorganisms and their synthetic analogs can be utilized, and these different sources are typically classified into 10 types, including fatty acids, lactones, terpenes, steroids, benzenoids, phenyl ethers, polyketides, alkaloids, nucleosides, and peptides. These compounds are isolated from marine invertebrates, including seaweeds, algae, fungi, bacteria, as well as larvae, sponges, worms, snails, mussels, and others. Any one or more (or various combinations thereof) of the above compounds and / or their equivalents (and / or any future developed compounds and / or their equivalents) can be used to create an anti-biofouling structure that prevents both microfouling, such as biofilm formation and bacterial attachment, and macrofouling, such as the attachment of large organisms, including barnacles or mussels, to one or more targeted species, or, if desired, can be used as a more "broad-spectrum" contaminant prevention against multiple biofouling organisms.

[0226] In one exemplary embodiment, a desirable spun polyester fiber-based woven fabric can be utilized as the enclosure material, and the fabric has a basis weight of approximately 410 grams per meter 2 (the weight of the base fabric before any coating or modification is included) (see Table 8).

Table 16

[0227] Table 9 shows some alternative fabric specifications that can be used as enclosure wall materials with various levels of utility.

Table 17

[0228] For various embodiments of structures or enclosures, the target additional weight of the paint / coating is currently approximately about 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 / meter 2 from (or up to ±10% thereof), can be set. Figures 27A and 27B illustrate various additional exemplary embodiments including various coating weights of the fabric for use in various enclosure designs.

[0229] In various embodiments where the addition of a biocide or other coating may be desired, in some embodiments, the coating can be applied to the enclosure after the enclosure is fully assembled and / or constructed. However, in other embodiments, it should be understood that the coating can be applied to some or all of the components of the enclosure before assembly and / or construction. In still other embodiments, some portions of the enclosure can be pre-coated and / or pre-treated, while other portions can be coated after assembly. Further, if the processes and / or treatment steps during the manufacture and / or assembly of the enclosure may involve techniques that can adversely affect the quality and / or performance of the biocide or other coating properties, it may be desirable to perform those processes and / or treatment steps on them prior to the application of the coating to the enclosure and / or enclosure components. For example, if a heat-sensitive biocide and / or coating is desired, a material processing technique involving high temperatures can be employed to fabricate and / or process the fabric and / or enclosure wall prior to the 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, a coating material or other additive (including biocide coatings or other materials) can be applied to and / or incorporated into the fabric of the enclosure, potentially resulting in a changed level of permeability, which can convert a material that may not be very suitable for protecting the substrate from biofouling into a more desirable one once it is coated. For example, as described herein, an uncoated polyester fabric that experimentally demonstrates a relatively high permeability to liquids (i.e., 150 mL of liquid passed through the test fabric in less than 50 seconds), which may not be very desirable for forming an enclosure to protect the substrate from biofouling. However, when properly coated to the desired level using a biocidal coating, the permeability of the coated fabric can be substantially reduced to a very 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 way, a planned permeability level can be optionally adjusted, like a "dial setting", for each selected fabric as desired.

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

[0232] FIG. 16A illustrates another exemplary embodiment of an uncoated 23×23 polyester woven fabric that is experimentally demonstrated to have a relatively low permeability to liquids (i.e., 100 mL of liquid passed through the test fabric in approximately 396 seconds), which can be above the lower limit of the desired permeability range to form an enclosure for protecting a substrate from biofouling, depending on local conditions, as described herein. When coated (see FIG. 16B), these materials became essentially impermeable prior to immersion but more permeable after immersion. As noted above, the desired permeability level can be adjusted, if desired, as a “dial setting” or in combination for each selected fabric. In various embodiments, the permeability of a given fabric and / or enclosure component can vary or be different, if desired, under wet or dry conditions.

[0233] During long-term immersion testing in an aqueous environment, no macrofouling occurred on the enclosures and / or substrates for any of the uncoated 23×23 polyester and coated polyester fabrics. Further, each of these materials underwent a significant increase in permeability during immersion, with the uncoated 23×23 polyester fabric allowing 150 mL of liquid to pass in 120 seconds, while the first 23×23 coated polyester fabric allowed 150 mL of liquid in 160 seconds and the second 23×23 coated polyester allowed 150 mL of liquid in 180 seconds.

[0234] In another alternative embodiment, FIGS. 17A - 17C illustrate natural material, jute fabric, which is uncoated (FIG. 17A), coated with a solvent - based biocidal coating (FIG. 17B), and coated with a water - based biocidal coating (FIG. 17C). During the permeability test, the uncoated jute fabric demonstrated a permeability of 50.99 ml / sec / cm2, while the coated jute fabrics had permeabilities of 52.32 ml / sec / cm2 and 38.23 ml / sec / cm2 for the solvent - based biocidal coating and water - based biocidal coating, respectively. After 32 days of immersion in salt water, the permeabilities of both coated fabrics increased significantly to 85.23 ml / sec / cm2 and 87.28 ml / sec / cm2, while the uncoated jute fabric decreased its permeability to 20.42 ml / sec / cm2. In the observation of fouling, the uncoated jute fabric received minimal fouling, and the coated jute fabrics received virtually no macro - fouling.

[0235] Additionally, in another alternative embodiment, uncoated fabric of 1 / 64 polyester was coated with a solvent - based biocidal coating and alternatively with a water - based biocidal coating. During the permeability test, 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 biocidal coating and water - based biocidal coating, respectively. After 32 days of immersion in salt water, the permeabilities of all 1 / 64 polyester fabrics decreased significantly to 10.99 ml / sec / cm2, 13.78 ml / sec / cm2, and 13.31 ml / sec / cm2, respectively. In the observation of fouling, the uncoated 1 / 16 polyester fabric received some fouling, while the coated 1 / 64 polyester fabric received virtually no macro - fouling.

[0236] A variety of different fabrics were manufactured, coated, and used in the construction and testing of biofouling prevention enclosures. In the first embodiment (shown in FIG. 18A having a scale of 1000 μm), a textured polyester fabric is coated with a biocide coating on a first substrate, and a significant amount of this coating completely penetrates through the fabric to the opposing second surface (the area of the coating on the second surface is thinner than other areas). FIG. 18B illustrates this coated fabric at a scale of 1000 μm. On average, this coated fabric had 523.54 (±2.33) pores per inch 2 and less than approximately 5 percent of the pores were blocked (on average).

[0237] FIG. 18C illustrates another preferred embodiment of a 100% spun polyester fabric, and FIG. 18D illustrates this fabric coated with a biocidal coating. During testing, the uncoated 100% polyester fabric demonstrated a permeability of 10.17 ml / sec / cm of the fabric 2 while the coated polyester fabric had permeabilities of 0.32 ml / sec / cm 2 and 1.08 ml / sec / cm 2 After 23 days of immersion, the permeabilities of both coated fabrics did not change significantly, the uncoated polyester fabric received minimal fouling, and the coated polyester fabric received 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 yield similar favorable results.

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

[0239] Experimentally, all of these cloth embodiments demonstrated a desirable level of permeability, which may be due to a large number of small pores, smaller sized fibers, and / or various combinations thereof. Various coating methods were very effective in coating and penetrating the cloth to the desired level, producing a very effective material for incorporation into a protective enclosure.

[0240] FIGS. 19 and 3 show various cloths potentially suitable for use in various embodiments of the present invention, along with exemplary permeability of these cloths in the uncoated and coated states. For example, at Port Canaveral Harbor (Port Canaveral, Florida, USA), 0.5 ml / sec / cm 2 ~25 ml / sec / cm 2 ~50 ml / sec / cm 2 ~75 ml / sec / cm 2 ~100 ml / sec / cm 2 or about 0.1 ml / sec / cm 2 ~ about 100 ml / sec / cm 2 cm 2 or about 1 ml / sec / cm 2 ~ about 75 ml / sec / cm 2or about 1 ml / sec / cm 2 to about 10 ml / sec / cm 2 or about 1 ml / sec / cm 2 to about 5 ml / sec / cm 2 or about 5 ml / sec / cm 2 to about 10 ml / sec / cm 2 or about 10 ml / sec / cm 2 to about 20 ml / sec / cm 2 or about 10 ml / sec / cm 2 to about 25 ml / sec / cm 2 or about 10 ml / sec / cm 2 to about 50 ml / sec / cm 2 or about 20 ml / sec / cm 2 to about 70 ml / sec / cm 2 or about 10 ml / sec / cm 2 to about 40 ml / sec / cm 2 or about 20 ml / sec / cm 2 to about 60 ml / sec / cm 2 or about 75 ml / sec / cm 2 to about 100 ml / sec / cm 2 or about 60 ml / sec / cm 2 to about 100 ml / sec / cm 2 or about 10 ml / sec / cm 2 to about 30 ml / sec / cm 2 The permeability range of, is sufficient (depending on local conditions) to prevent significant fouling from occurring on and / or within the enclosure and / or on the protected substrate, while still being able to allow sufficient water flow to inhibit and / or prevent anoxia within the enclosure. It has been experimentally determined. Additionally, a cloth having a permeability of 0.5 ml / sec / cm 2 or less may be suitable for various enclosure embodiments, and occasional low-oxygen condition periods may be acceptable and / or desirable. Permeabilities lower than these ranges can lead to anoxic conditions during periods of low water movement in some areas, which may not be very desirable and / or may be undesirable in various embodiments. In another exemplary embodiment, at least 0.32 ml / sec / cm 2and up to 10.17 ml / sec / cm 2 The permeability range of 2 was determined to be within the optimal range of desired permeability characteristics and / or the desired range of expected permeability changes during the life of the enclosure. In other embodiments, at least 1.5 ml / sec / cm 2 and up to 8.0 ml / sec / cm 2 may be desirable (and any combination of the various ranges disclosed herein). Often, for a given fouling organism, the incidence of fouling intrusion and / or the rate of fouling growth in a given area and / or body of water is highly dependent on the multiplicity of interrelated factors, as well as the local and / or seasonal conditions of the intended use area (and, in particular, the substrate intended to be protected), and the acceptable range of permeability of a given fabric for a given enclosure design can vary widely. Thus, the permeability of a fabric that may be optimal and / or suitable for one enclosure design and / or location may not be as optimal and / or suitable for another enclosure design and / or location. In FIG. 19, the "more" and "less" fouling arrows of the graph are related to the fouling observed on the protected substrate, and the numerical values and ranges of these permeabilities therein are to be interpreted as general trends of the ability and / or permeability of a given fabric to provide anti-fouling protection while avoiding long-term anoxic conditions in a given body of water, but should not be interpreted as excluding 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 the desired permeability range over its service life in its original location (or, if desired, until the desired biofilm layer is established), such that any potential increase in the permeability of the material due to changes in the structure and / or material of the enclosure (as an example) desirably approximates the various expected decreases in the permeability of the material due to pore clogging by organic and / or inorganic debris (including any biofouling of the material and / or its pores that may occur). This balance desirably serves to maintain the integrity and / or function of the enclosure and the characteristics of the differentiated environment over the long term, providing significant protection to the enclosure and / or the protected substrate.

[0242] In various embodiments, the enclosure wall may incorporate various materials that are subject to changes in permeability during a long-term immersion test in an aqueous environment. For example, uncoated synthetic materials can generally become less permeable over time (which can be due to progressive fouling of the fabric once positioned around the substrate), while some materials coated with biocidal coatings can undergo various permeability changes, including some embodiments where they become less permeable over time. Additionally, natural test fibers (hessian) in an uncoated state became more permeable, while hessian coated with a biocide became less permeable over time. In various embodiments, changes in coating parameters (i.e., addition / thickness of the coating, application method, vacuum application to maintain and / or increase pore size, drying parameters, etc.), and various fiber parameters (i.e., construction, material, initial permeability, presence or absence of constraints during drying, presence or absence of heat setting, etc.) can enable a wide range of desired permeability characteristics and expected permeability changes during the life of a given enclosure design. Thus, it is possible to affect (and / or control) whether the permeability increases or decreases over time for a certain period when deployed in an aqueous environment and the correlation associated 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 permeable in 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 inner / outer surface of the structure, and the structure or a portion thereof has a permeability of about 100 milliliters per second per square centimeter of the substrate, about 100 milliliters per minute per square centimeter of the substrate, or a value therebetween, or greater / less permeability of water when positioning the structure around the substrate or thereafter.

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

[0245] Figures 20 and Table 10 (below) show one exemplary test of the 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 when water exchange occurred inside and outside the permeable wall of the enclosure. The test showed that the residence time of rhodamine in this enclosure having its dimensions and wall permeability was approximately 4 hours 10 minutes, a half-life of 3 hours, and a flow rate of about 0.0027 ml / cm 2 / second. [Table 18]

[0246] The rhodamine dye test was used as an analogue to determine the water exchange rate within various test enclosures. For example, a YSI Total Algae Sensor (TAL) was placed in a fully bagged stern mimic. Rhodamine at a concentration of 0.9 mg / L was added to the stern mimic. When the data had returned to the background concentration of the dye within the bag, the YSI was placed in open water for 2 days to obtain open water readings for comparison to the non-dosed bag level. Residence time, half-life, and flow rate were calculated from the rhodamine data. The residence time was calculated as 37% of the initial concentration of the rhodamine dye. The half-life was calculated as 69.3% of the residence time (using these calculations found in the literature). The flow rate was calculated by taking twice the volume (considering one volume of inflow and one volume of outflow) and dividing it by the residence time and surface area. To more accurately capture the dilution rate, the rhodamine concentration in mg / L was graphed after subtracting the background dye. The test results indicate that it took approximately 26 hours for the dye concentration in the stern mimic to stabilize and return to natural levels. The residence time was calculated as 4 hours 10 minutes and the flow rate was calculated as 0.0027 mL / cm 2 / second.

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

[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 substrate fouling, settlement, mobilization, and ultimately macrofouling. Once positioned around ...

Claims

1. 1. A material for reducing biofouling on a surface at least partially immersed in an aqueous environment, said material comprising: a structure that is or becomes water permeable during use, the structure defining an open end adapted to receive through the substrate, the structure defining an enclosure having one or more walls that remain spaced apart from a surface of the substrate in a non-sealed arrangement by the 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 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 being flexible and defining a first side and a second side; 1. A material comprising: a structure at least partially surrounding a surface in an aqueous environment such that a first side of the structure faces the surface; wherein the structure allows fluid exchange through the structure to the surface while preventing or limiting biofouling on the surface such that a first chemical composition of the aqueous environment between the surface and the first side of the structure is different from a second chemical composition of the aqueous environment outside the second side of the structure; and wherein the first chemical composition is measured in an aqueous environment proximate to the surface and the second chemical composition is measured in an aqueous environment at a spaced distance from the second side of the structure away from the surface.

2. The material of claim 1 , wherein the structure comprises a biocide.

3. 10. The material of claim 1, wherein said structure provides an average water exchange of about 0.1% to 200% of the volume of water passing through per hour when said structure at least partially surrounds said surface in said aqueous environment.

4. 10. The material of claim 1, wherein said structure provides an average water exchange of about 0.1% to 500% of the volume of water passing through per hour when said structure at least partially surrounds said surface in said aqueous environment.

5. 10. The material of claim 1, wherein said structure has a water permeability in the range of about 0.06 to 46.71 milliliters per second per square centimeter per hour when said structure at least partially surrounds said surface in said aqueous environment.

6. 10. The material of claim 1, wherein said structure has a water permeability in the range of about 0.90 to 14.72 milliliters per second per square centimeter per hour when said structure at least partially surrounds said surface in said aqueous environment.

7. 10. The material of claim 1, wherein said structure has a water permeability of less than or equal to about 100 milliliters per second per square centimeter when said structure at least partially surrounds said surface in said aqueous environment.

8. 2. The material of claim 1, 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, silica, salinity, and chlorophyll.

9. 9. The material of claim 8, 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.

10. 10. The material of claim 1, wherein the distance spaced from the second side of the structure is 12 inches.

11. 10. The material of claim 1, wherein the first chemical composition is measured in an aqueous environment proximate to the surface at a location away from the first side of the structure and away from the surface.

12. 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 fluid permeable, said structure defining an open end adapted to receive fluid therethrough, said 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, said structure comprising at least one of a mesh, a lattice, a fenestration, and a hole that allows fluid to flow therethrough, said 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; A device wherein when the structure at least partially surrounds the substrate in the aqueous environment in the non-completely sealed configuration, the structure separates the aqueous environment into an aqueous environment local to the substrate and an open aqueous environment, and provides for fluid flow through the open aqueous environment while reducing biofouling in the local aqueous environment.

13. 13. The device of claim 12, wherein the structure provides an average water exchange of about 0.1% to 200% of the volume of water passing through per hour when the structure at least partially surrounds the substrate in the aqueous environment.

14. 13. The device of claim 12, wherein the structure has a water permeability of about 100 milliliters per second per square centimeter or less when the structure at least partially surrounds the substrate in the aqueous environment.

15. 13. The device of claim 12, wherein when the structure at least partially surrounds the substrate in the aqueous environment, the structure allows fluid exchange through the structure to the substrate while preventing or limiting biofouling on the surface such that a first chemical composition of the localized aqueous environment is different from a second chemical composition of the open aqueous environment.

16. 1. A roll or sheet of a deployable material for reducing biofouling on a surface at least partially immersed in an aqueous environment, said material comprising: a structure that is or becomes fluid permeable, 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 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 being flexible and defining a first side and a second side; A roll or sheet of material, wherein when the structure at least partially surrounds the surface 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 surface while preventing or limiting biofouling on the surface such that a first chemical composition of the aqueous environment between the surface and the first side of the structure is different from a second chemical composition of the aqueous environment outside the second side of the structure, the first chemical composition being measured in the aqueous environment proximate to the surface and the second chemical composition being measured in the aqueous environment at a spaced distance from the second side of the structure away from the surface.

17. 17. A roll or sheet of material as claimed in claim 16, wherein the structure comprises a biocide.

18. 17. The roll or sheet of material of claim 16, wherein said structure provides an average water exchange of about 0.1% to 500% of the volume of water passing through per hour when said structure at least partially surrounds said surface in said aqueous environment.

19. 17. The roll or sheet of material of claim 16, wherein said structure has a water permeability in the range of about 0.06 to 46.71 milliliters per second per square centimeter per hour when said structure at least partially surrounds said surface in said aqueous environment.

20. 17. The roll or sheet of material of claim 16, 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, silica, salinity, and chlorophyll.

21. 21. The roll or sheet of material of claim 20, 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.

22. 17. The roll or sheet of material of claim 16, wherein said second chemical composition is measured in said aqueous environment 12 inches away from said second side of said structure.

23. 17. The roll or sheet of material of claim 16, wherein the first chemical composition is measured in an aqueous environment adjacent to the surface at a location away from the first side of the structure and away from the surface.

24. 1. A device for reducing biofouling on a surface at least partially submerged in an aqueous environment, said device comprising: a structure that is or becomes fluid permeable, 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 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 being flexible and defining a first side and a second side; A device wherein when the structure at least partially surrounds the surface 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 surface while preventing or limiting biofouling on the surface such that a first chemical composition of the aqueous environment between the surface and the first side of the structure is different from a second chemical composition of the aqueous environment outside the second side of the structure, and the first chemical composition is measured in the aqueous environment proximate to the surface and the second chemical composition is measured in the aqueous environment at a distance away from the second side of the structure away from the surface.

25. 25. The device of claim 24, 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, said structure attached to said at least one floating boom and suspended in said aqueous environment.

26. 25. The device of claim 24, wherein the structure comprises a biocide.

27. 25. The device of claim 24, wherein said structure provides an average water exchange of about 0.1% to 500% of the volume of water passing through per hour when said structure at least partially surrounds said surface in said aqueous environment.

28. 25. The device of claim 24, wherein the structure has a water permeability in the range of about 0.06 to 100 milliliters per second per square centimeter per hour when the structure at least partially surrounds the surface in the aqueous environment.

29. 25. The device of claim 24, 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, silica, salinity, and chlorophyll.

30. 30. The device of claim 29, 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.

31. 25. The device of claim 24, wherein the distance spaced from the second side of the structure is 12 inches.

32. 25. The device of claim 24, wherein the first chemical composition is measured in an aqueous environment proximate to the surface at a location away from the first side of the structure and away from the surface.

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