Seaweed farming system

Abstract

An aquaculture system is disclosed that includes a cultivation substrate configured to promote seaweed anchorage formation and seaweed attachment. The cultivation system can include one or more of a nutrient phase, an adhesive, a bioactive agent, and a liquid-containing phase. The cultivation substrate can be patterned. The cultivation system can specifically retain and maintain viability of certain seaweed species, such as dulse, kelp, and nori.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Provisional Application No. 63 / 044,285, filed June 25, 2020, which is incorporated by reference in its entirety for all purposes.

[0002] Field The present disclosure relates generally to aquaculture systems, and more particularly, to a seaweed cultivation system configured to assist in fastener formation. [Background technology]

[0003] background Current methods of culturing seaweed from spores include using textured nylon "cultivation strings" or "seed strings" to which the spores attach weakly during seeding in the laboratory. The cultivation strings with weakly attached juvenile seaweed (gametophytes and sporophytes) are wound onto ropes at seaweed farms, where the ropes are placed in water. This method is inherently variable in terms of yield and production, primarily due to biofouling (i.e., contamination of the seed strings with unwanted species of seaweed and other organisms). Biofouling can significantly reduce seaweed growth and yield. Traditionally, effective anti-biofouling materials (smooth, low coefficient of friction films) also reduce seaweed growth and yield due to poor attachment to these substrates. Other factors that affect yield and production include the susceptibility of seaweed to damage, such as from currents, temperature changes, and nutrient availability. Additionally, poor packaging and handling can result in damage and loss of juvenile seaweed. Current approaches to improve the stability of juvenile seaweed in aquaculture strings focus on the surface texture of the existing fibers. In fact, the fiber texture of the aquaculture string is very important for the success of seaweed cultivation. There is a need for a substrate that can provide effective attachment and growth of seaweed while providing effective anti-biofouling properties. Summary of the Invention

[0004] Abstract Various embodiments are directed to an aquaculture system configured to retain and maintain viability of spores.

[0005] According to one example ("Example 1"), an aquaculture system includes an aquaculture substrate including a low-porosity substrate having a porosity of about 10% or less and a fibrillated sub-micron surface structure configured to retain seaweed by an anchoring device.

[0006] According to another example ("Example 2"), in addition to Example 1, said fibrillated submicron surface structure is characterized by an average interfibril distance of 1000 nm or less.

[0007] According to another example ("Example 3"), further to Examples 1 or 2, the fibrillated submicron surface structures have an average depth of about 1000 nm or less.

[0008] According to another example ("Example 4"), in addition to any one of Examples 1-3, the fibrillated submicron surface structures have an average depth of about 5 nm or less.

[0009] According to another example ("Example 5"), further to any of Examples 1-4, the low porosity substrate is from about 25.4 μm (1 mil) to about 762 μm (30 mils) thick.

[0010] According to another example ("Example 6"), further to any of Examples 1-5, the low porosity substrate is from about 25.4 μm (1 mil) to about 127 μm (5 mils) thick.

[0011] According to another example ("Example 7"), in addition to any one of Examples 1-6, the aquaculture substrate is configured as a tape, a substrate, a woven article, a nonwoven article, a braided article, a knitted article, a fabric, a particle dispersion, or a combination of two or more of the foregoing.

[0012] According to another example ("Example 8"), in addition to any one of Examples 1-7, the aquaculture substrate includes at least one of a backer layer, a carrier layer, a laminate of multiple layers, a composite material, or a combination thereof.

[0013] According to another example ("Example 9"), in addition to any one of Examples 1-8, the low porosity substrate comprises an expanded fluoropolymer.

[0014] According to another example ("Example 10"), in addition to Example 9, the expanded fluoropolymer is one of expanded fluorinated ethylene propylene (eFEP), porous perfluoroalkoxyalkane (PFA), expanded ethylene tetrafluoroethylene (eETFE), expanded vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene polymer (eVDF-co-(TFE or TrFE)), and expanded polytetrafluoroethylene (ePTFE).

[0015] According to another example ("Example 11"), in addition to any one of Examples 1-10, the low porosity substrate is an expanded polytetrafluoroethylene (ePTFE) substrate.

[0016] According to another example ("Example 12"), in addition to any one of Examples 1-8, the low porosity substrate comprises an expandable thermoplastic polymer.

[0017] According to another example ("Example 13"), in addition to Example 12, the expanded thermoplastic polymer is one of expanded polyester sulfone (ePES), expanded ultra-high molecular weight polyethylene (eUHMWPE), expanded polylactic acid (ePLA), and expanded polyethylene (ePE).

[0018] According to another example ("Example 14"), in addition to any one of Examples 1-8, the low porosity substrate includes an expanding polymer.

[0019] According to another example ("Example 15"), in addition to Example 14, the expanding polymer is an expanding polyurethane (ePU).

[0020] According to another example ("Example 16"), in addition to any one of Examples 1-8, the low porosity substrate is expanded polyparaxylylene (ePPX).

[0021] According to another example ("Example 17"), in addition to Example 11, the PTFE substrate has a viscosity of about 0.015 g-mm / m 2 / day or less and is formed by a process that includes: (a) preparing a biaxially expanded PTFE film; (b) densifying the expanded PTFE film; and (c) expanding the densified expanded PTFE film.

[0022] According to another example ("Example 18"), in addition to Example 18, the densified expanded PTFE film is expanded in step (c) at a temperature above the crystalline melt temperature of PTFE.

[0023] According to another example ("Example 19"), in addition to Example 17 or Example 18, the expanded PTFE film is sintered prior to step (b).

[0024] According to another example ("Example 20"), in addition to any one of claims 17 to 19, the biaxially stretched PTFE film includes two or more layers of expanded PTFE.

[0025] According to another example ("Example 21"), in addition to any one of Examples 17-20, steps (a)-(c) are carried out in a continuous manner.

[0026] According to another example ("Example 22"), in addition to any one of Examples 1-21, the aquaculture substrate further comprises a highly porous substrate having a node and fibril microstructure characterized by a porosity of at least 30%, an average interfibril distance of about 1 μm to about 500 μm, or an average pore size of about 1 μm to about 500 μm.

[0027] According to another example ("Example 23"), in addition to Example 22, the highly porous substrate comprises an expanded fluoropolymer.

[0028] According to another example ("Example 24"), in addition to Example 23, the expanded fluoropolymer is one of expanded fluorinated ethylene propylene (eFEP), porous perfluoroalkoxyalkane (PFA), expanded ethylene tetrafluoroethylene (eETFE), expanded vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene polymer (eVDF-co-(TFE or TrFE)), and expanded polytetrafluoroethylene (ePTFE).

[0029] According to another example ("Example 25"), in addition to any one of Examples 22-24, the highly porous substrate is an expanded polytetrafluoroethylene (ePTFE) substrate.

[0030] According to another example ("Example 26"), in addition to Example 22, the highly porous substrate comprises an expanded thermoplastic polymer.

[0031] According to another example ("Example 27"), in addition to Example 26, the expanded thermoplastic polymer is one of expanded polyester sulfone (ePES), expanded ultra-high molecular weight polyethylene (eUHMWPE), expanded polylactic acid (ePLA), and expanded polyethylene (ePE).

[0032] According to another example ("Example 28"), in addition to Example 22, the highly porous substrate includes an expanding polymer.

[0033] According to another example ("Example 29"), in addition to Example 28, the expanding polymer is an expanding polyurethane (ePU).

[0034] According to another example ("Example 30"), in addition to Example 22, the highly porous substrate is expanded polyparaxylylene (ePPX).

[0035] According to another example ("Example 31"), in addition to any one of Examples 22-30, the highly porous substrate is hydrophobic.

[0036] According to another example ("Example 32"), in addition to any one of Examples 22-31, the low porosity substrate and the high porosity substrate comprise the same material.

[0037] According to another example ("Example 33"), in addition to any one of Examples 22-32, the cultivation substrate is a patterned substrate having a pattern of low porosity substrates and high porosity substrates.

[0038] According to another example ("Example 34"), in addition to Example 33, the pattern of the low porosity substrate and the high porosity substrate is an organized or selective pattern.

[0039] According to another example ("Example 35"), in addition to Example 33, the pattern of the low porosity substrate and the high porosity substrate is a random pattern.

[0040] According to another example ("Example 36"), in addition to any one of Examples 1-35, the aquaculture system includes a nutrient phase associated with at least a portion of the aquaculture substrate.

[0041] According to another example ("Example 37"), further to Example 36, the nutrient phase promotes seaweed growth and / or attachment of seaweed to the cultivation substrate.

[0042] According to another example ("Example 38"), further to Example 36 or Example 37, at least a portion of the nutrient phase is entrained within the culture substrate, entrained on the culture substrate, or entrained within and on the culture substrate.

[0043] According to another example ("Example 39"), in addition to any one of Examples 36-38, the nutrient phase is present as a coating on a surface of the culture substrate.

[0044] According to another example ("Example 40"), in addition to any one of Examples 1-39, the aquaculture substrate is provided with a plurality of particles in a dispersion formulated for deposition onto a backer layer or carrier substrate.

[0045] According to another example ("Example 41"), in addition to any one of Examples 1-40, the cultivation substrate is asymmetric and includes fibrillated submicron surface structures configured to retain seaweed on only one side.

[0046] According to another example ("Example 42"), a method of cultivating seaweed includes contacting a population of seaweed gametophytes and / or sporophytes with a cultivation substrate of any one of Examples 1 to 41 until at least a portion of the population of seaweed gametophytes and / or sporophytes form anchorages to the nanostructures of the cultivation substrate.

[0047] According to another example ("Example 43"), in addition to Example 42, the method includes placing the aquaculture system in an open water environment after a portion of the population of seaweed gametophytes and / or sporophytes have formed anchorages to nanostructures of the aquaculture substrate. [Brief description of the drawings]

[0048] BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments, and together with the description, serve to explain the principles of the disclosure.

[0049] [Figure 1A] Figure 1A is a photograph showing naturally occurring seaweed-rock interactions. Source: Morrison L, Feely M, Stengel DB, Blamey N, Dockery P, Sherlock A, Timmins E (2009) Seaweed attachment to bedrock: biophysical evidence for a new geophysical paradigm. Geobiology 7:477-487.

[0050] [Figure 1B]Figure 1B is a detailed view of the area identified by the dashed box in Fig. 1A. Source: Morrison L, Feely M, Stengel DB, Blamey N, Dockery P, Sherlock A, Timmins E (2009) Marine algal attachment to bedrock: biophysical evidence for a new geophysical paradigm. Geobiology 7:477-487.

[0051] [Diagram 2] 2A-2D are scanning electron microscope (SEM) micrographs taken at various magnifications showing the nanostructure of low-porosity substrates according to some embodiments. Scale bars provided in Figures 2A, 2B, 2C, and 2D are 100 μm, 10 μm, 5 μm, and 5 μm, respectively.

[0052] [Diagram 3] 3A-3D are scanning electron microscope (SEM) micrographs taken at various magnifications showing the surface structure of a substrate according to some embodiments. The scale bars provided in Figures 3A, 3B, 3C, and 3D are 100 μm, 10 μm, 5 μm, and 5 μm, respectively.

[0053] [Figure 4] FIG. 4 is a photograph showing a kelp anchoring network on the surface of a low porosity substrate, according to some embodiments.

[0054] [Diagram 5] FIG. 5 is a collection of photographs showing kelp growth on the membranes shown in FIGS. 2A-D (two samples on the left) and on the membranes shown in FIGS. 3A-3D (two samples on the right), according to some embodiments.

[0055] [Figure 6] FIG. 6 is a collection of photographs showing the growth of glue on the films shown in FIGS. 2A-D (two samples on the left) and on the films shown in FIGS. 3A-3D (two samples on the right), according to some embodiments.

[0056] [Figure 7] FIG. 7 is a collection of photographs showing dalus growth on the films shown in FIGS. 2A-D (two samples on the left) and on the films shown in FIGS. 3A-3D (two samples on the right), according to some embodiments.

[0057] [Figure 8] FIG. 8 is a scanning electron microscope (SEM) micrograph showing the microstructure of a highly porous substrate, according to some embodiments.

[0058] [Figure 9] FIG. 9 is an SEM micrograph showing the microstructure depicted in FIG. 1, but at a higher magnification.

[0059] [Figure 10] FIG. 10 is a SEM micrograph showing the microstructure of a highly porous substrate, according to some embodiments.

[0060] [Figure 11] FIG. 11 is an SEM micrograph showing the microstructure depicted in FIG. 3, but at a higher magnification.

[0061] [Figure 12] FIG. 12 is a schematic diagram illustrating the microstructure of a highly porous substrate, according to some embodiments.

[0062] [Figure 13] FIG. 13 is a micrograph of FIG. 9 with cartoon representations of spores, either 10 μm or 30 μm in diameter, superimposed in the interfibrillar spaces, according to some embodiments.

[0063] [Figure 14A] FIG. 14A is a cross-sectional SEM micrograph showing ingrowth of dulse seaweed into the microstructure of a highly porous substrate, according to some embodiments.

[0064] [Figure 14B]FIG. 14B is a cross-sectional SEM micrograph showing the ingrowth depicted in FIG. 14A, but at a higher magnification.

[0065] [Figure 14C] FIG. 14C is a cross-sectional optical fluorescence microscopy photomicrograph showing ingrowth of Dulse seaweed into the microstructure of a highly porous substrate, according to some embodiments.

[0066] [Figure 15] FIG. 15 shows a surface SEM micrograph (top panel) showing the microstructure of a highly porous substrate before seeding with sugar kelp spores, and an optical fluorescence microscope micrograph (bottom panel) showing the highly porous substrate after seeding with sugar kelp spores and their germination, according to some embodiments.

[0067] [Figure 16] FIG. 16 shows two surface SEM micrographs taken at different magnifications showing juvenile dulse ingrowth into the microstructures, according to some embodiments.

[0068] [Figure 17] FIG. 17 is a surface optical fluorescence microscopy photomicrograph showing ingrowth of Dulse seaweed into the microstructure of a highly porous substrate, according to some embodiments.

[0069] Those skilled in the art will readily appreciate that the accompanying drawings referred to herein are not necessarily drawn to scale, but are exaggerated or diagrammatically illustrated for purposes of illustrating various aspects of the present disclosure, and in that regard the drawings should not be construed as limiting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0070] Detailed Description Definitions and Terminology This disclosure is not intended to be read in a limiting sense, for example, the terms used in this application should be read broadly in relation to the meaning ascribed to such terms in the art.

[0071] With respect to the term imprecision, the terms "about" and "approximately" may be used interchangeably to refer to measurements that include the stated measurement and also include any measurement that is reasonably close to the stated measurement. A measurement that is reasonably close to the stated measurement deviates from the stated measurement by a reasonably small amount, as understood and readily ascertained by one of ordinary skill in the relevant art. Such deviations may result from measurement errors, differences in calibration of measuring and / or manufacturing equipment, human error in reading and / or setting measurements, fine-tuning made to optimize performance and / or construction parameters given differences in measurements related to other components, specific implementation scenarios, imprecise adjustment and / or manipulation of objects by humans or machines, and the like. In cases where it is determined that such reasonably small difference values ​​are not readily ascertainable by one of ordinary skill in the relevant art, the terms "about" and "approximately" may be understood to mean plus or minus 10% of the stated value.

[0072] Certain terminology is used herein for convenience. For example, words such as "top," "bottom," "upper," "lower," "left," "right," "horizontal," "vertical," "upward," "downward," and the like, simply describe the orientation of parts in the configuration or mounting position shown in the figures. In fact, referenced components may be oriented in any direction. Similarly, throughout this disclosure, where processes or methods are shown or described, the methods may be performed in any order or simultaneously, unless it is clear from the context that the method is dependent on a particular operation being performed first.

[0073] A coordinate system is shown in the figures and referenced throughout the description, where the "Y" axis corresponds to the vertical direction, the "X" axis corresponds to the horizontal or lateral direction, and the "Z" axis corresponds to the medial-lateral direction.

[0074] Description of Various Embodiments The present disclosure relates to an aquaculture system including a culture substrate for use in holding, cultivating and / or growing seaweed, and related methods and apparatus. In some embodiments, the aquaculture system is operable to cultivate seaweed in an open water environment.

[0075] The aquaculture system according to the present disclosure can be used for the culture and growth of spores, as well as the transport and attachment of spores and / or gametophytes / sporophytes. In certain embodiments, the aquaculture substrates described herein can be used as improved growth substrates for the growth and culture of seaweed forms (e.g., spores, gametophytes, sporophytes), resulting in improved yields and production compared to current aquaculture practices.

[0076] In some embodiments, the aquaculture system includes an aquaculture substrate that itself includes a low porosity substrate having a fibrillated submicron surface structure on at least one surface of the substrate, the fibrillated submicron surface structure of the low porosity substrate attaching seaweed to the aquaculture substrate via the seaweed anchoring device.

[0077] Anchorages are root-like structures at the base of seaweed that anchor the seaweed to a substrate, e.g., a rock. Anchorages vary in shape and structure depending on the species. The type of substrate can also affect the shape and structure of the anchorage. Seaweed anchorages differ from terrestrial plant roots in that they have no nutrient uptake function, but only act as anchors.

[0078] FIG. 1A depicts the region of interaction between kelp (Fucus vesiculosus) and granitic bedrock. The cross section depicts the adhesive apparatus (arrows) and shows the algal side branches (1), main axis (2), adhesive zone (3), and adhesive apparatus-bedrock interface (4). FIG. 1B shows a detailed view of the area within the dashed box in FIG. 1A, detailing three zones of physicochemical activity including the adhesive apparatus interface. The arrows in FIG. 1B indicate rock fragments that have been incorporated and dispersed in the adhesive apparatus tissue of the algae.

[0079] As described herein, it has been surprisingly found that the nanostructures found on certain low porosity substrates promote and assist anchor formation on the substrate surface. Figures 2A-2D are SEM micrographs showing nanostructures on the surface of a low porosity expanded polytetrafluoroethylene (ePTFE) substrate according to some embodiments. Figures 2A-2C show nanostructures on a first side of a low porosity substrate at increasing magnification. The scales presented are 100 μm (Figure 2A), 10 μm (Figure 2B) and 5 μm (Figure 2C). Figure 2D shows the nanostructures on a second side of a low porosity substrate (provided at a scale of 5 μm). At the lowest magnification (Figure 2A), the surface of the low porosity substrate appears generally smooth. However, a fibrillated submicron surface structure is evident at higher magnifications (Figures 2B-2D). As shown, the fibrillated submicron surface structure is defined by a plurality of fibrils. The fibrils define interfibrillar spaces. In some embodiments, the fibrils of the fibrillated submicron surface structure are interconnected at nodes, as shown in Figures 2A-2D. In certain embodiments, the fibrillated submicron surface structure is free of nodes or substantially free of nodes.

[0080] The fibrils have a defined average interfibril distance, and in some embodiments, the average interfibril distance is from about 1 nm to about 1000 nm, from about 1 nm to about 500 nm, from about 1 nm to about 200 nm, from about 1 nm to about 50 nm, from about 1 nm to about 20 nm, from about 1 nm to about 10 nm, from about 1 nm to about 5 nm, from about 5 nm to about 500 nm, from about 5 nm to about 200 nm, from about 5 nm to about 100 nm, from about 5 nm to about 50 nm, from about 5 nm to about 20 nm, from about 5 nm to about 10 nm, from about 10 nm to about 100 nm, from about 10 nm to about 500 nm, from about 10 nm to about 20 0 nm, about 10 nm to 100 nm, about 10 nm to about 75 nm, about 10 nm to about 50 nm, about 10 nm to about 25 nm, about 25 nm to about 200 nm, about 25 nm to about 150 nm, about 25 nm to about 100 nm, about 25 nm to about 50 nm, about 50 nm to about 200 nm, about 50 nm to about 150 nm, about 50 nm to about 100 nm, about 100 nm to about 500 nm, about 100 nm to about 200 nm, about 100 nm to about 150 nm, about 150 nm to about 500 nm, or about 150 nm to about 200 nm. In some embodiments, the fibrils can have an average interfibril distance of about 1 nm, about 2 nm, about 3 nm, about 4 nm, about 5 nm, about 10 nm, about 20 nm, about 30 nm, about 40 nm, about 50 nm, about 60 nm, about 70 nm, about 80 nm, about 90 nm, about 100 nm, about 110 nm, about 120 nm, about 130 nm, about 140 nm, about 150 nm, about 160 nm, about 170 nm, about 180 nm, about 190 nm, about 200 nm, about 250 nm, about 300 nm, about 400 nm, about 500 nm, about 600 nm, about 700 nm, about 800 nm, about 900 nm, or about 1000 nm.

[0081] In certain embodiments, the fibrillated submicron surface structures have an average depth of about 1000 nm or less. That is, the fibrillated submicron surface structures are present on the surface of the low porosity substrate to a depth of about 1000 nm or less in the z dimension into the low porosity substrate. In some embodiments, the average depth of the fibrillated submicron surface structures is from about 1 nm to about 1000 nm, from about 1 nm to about 500 nm, from about 1 nm to about 300 nm, from about 1 nm to about 100 nm, from about 1 nm to about 50 nm, from about 1 nm to about 20 nm, from about 1 nm to about 10 nm, from about 1 nm to about 5 nm, from about 5 nm to about 1000 nm, from about 5 nm to about 500 nm, from about 5 nm to about 300 nm, from about 5 nm to about 100 nm, from about 5 nm to about 50 nm, from about 5 nm to about 20 nm, from about 5 nm to about 10 nm, from about 10 nm to about 100 0 nm, about 10 nm to about 500 nm, about 10 nm to about 300 nm, about 10 nm to about 100 nm, about 10 nm to about 75 nm, about 10 nm to about 50 nm, about 10 nm to about 25 nm, about 25 nm to about 1000 nm, about 25 nm to about 500 nm, about 25 nm to about 300 nm, about 25 nm to about 100 nm, about 25 nm to about 75 nm, about 25 nm to about 50 nm, about 50 nm to about 1000 nm, about 50 nm to about 500 nm, about 50 nm to about 300 nm, or about 50 nm to about 100 nm. In some embodiments, the fibrillated submicron surface structures can have an average depth of about 1 nm, about 2 nm, about 3 nm, about 4 nm, about 5 nm, about 10 nm, about 20 nm, about 30 nm, about 40 nm, about 50 nm, about 60 nm, about 70 nm, about 80 nm, about 90 nm, or about 100 nm.

[0082] In some embodiments, the fibrillated submicron surface structure comprises two or more layers of nodes and fibrils. Such a configuration is shown, for example, in FIG. 2C, where fibrils appear to overlap one another. In certain embodiments, the depth of the fibrillated submicron surface structure exhibits a layered node and fibril configuration.

[0083] In some embodiments, the low porosity substrate has a porosity of about 10% or less. The porosity of the low porosity substrate can be about 1% to about 10%, about 1% to about 5%, or about 5% to about 10%. In some embodiments, the porosity of the low porosity substrate can be about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or about 10%.

[0084] The low porosity substrate can have a thickness of about 1 mil (0.001 inch; 25.4 μm) to about 30 mils (0.03 inch; 254 μm). In some embodiments, the thickness of the low porosity substrate can be about 1 mil (0.001 inch; 25.4 μm) to about 10 mils (0.01 inch; 254 μm), or about 1 mil (0.001 inch; 25.4 μm) to about 5 mils (0.005 inch; 254 μm). In some embodiments, the thickness of the low porosity substrate can be about 1 mil (0.001 inch; 25.4 μm), about 2 mils (0.002 inch; 50.8 μm), about 3 mils (0.003 inch; 76.2 μm), about 4 mils (0.004 inch; 101.6 μm), about 5 mils (0.005 inch; 127 μm), about 6 mils (0.006 inches; 152.4 μm), about 7 mils (0.007 inches; 177.8 μm), about 8 mils (0.008 inches; 203.2 μm), about 9 mils (0.009 inches; 228.6 μm), about 10 mils (0.01 inches; 254 μm), about 12 mils (0.012 inches; 304.8 μm), about 15 mils (0.015 inches; 381 μm), about 20 mils (0.02 inches; 508 μm), about 25 mils (0.025 inches; 635 μm), or about 30 mils (0.03 inches; 762 μm).

[0085] The fibrillated sub-micron surface structure of the low-porosity substrate of the aquaculture substrate is configured to hold the seaweed by the anchorage. The depth of the fibrillated sub-micron surface structure and the porosity of the low-porosity substrate are sufficient to hold the seaweed by the anchorage while resisting ingrowth of the seaweed into the low-porosity substrate beyond the depth of the node and fibril nanostructure. In some embodiments, a plurality of seaweed spores are seeded on the aquaculture substrate and allowed to develop into juvenile seedlings, during which the seaweed develops anchorage structures on the surface of the aquaculture substrate. In other embodiments, a plurality of juvenile seedlings (e.g., sporophytes and / or gametophytes) are seeded directly on the aquaculture substrate and allowed to form anchorages thereon. The plurality of seaweed spores and / or juvenile seaweed may all be of the same species or may be of two or more different species. In some embodiments, two different seaweed species exhibit a symbiotic relationship when cultured or grown together.

[0086] In addition to retaining seaweed via the seaweed fasteners, the aquaculture system and substrate of the present disclosure can promote the germination and growth of seeded seaweed spores, as well as the growth of juvenile and mature seaweed. The aquaculture substrate can, for example, create a microenvironment that is conducive to the germination and growth of seeded seaweed spores, as well as the growth of juvenile and mature seaweed.

[0087] In certain embodiments, the cultivation substrate provides selective nanostructures that encourage the formation of anchorages and subsequent growth of one or more target seaweed species while inhibiting or preventing the attachment or growth of non-target species or other organisms. That is, the nanostructures of the cultivation substrate support the attachment and growth of the seaweed species while inhibiting biofouling. In some embodiments, when a biofouling species (e.g., a non-target species or other organism) attaches to the cultivation substrate, the attachment is weaker than that of the target seaweed species, and the biofouling species can be removed, for example, by rinsing. In such embodiments, physical removal of the biofouling species does not result in significant removal of the target species.

[0088] In some embodiments, the aquaculture substrate promotes rapid and healthy growth of the target species, allowing the target species to produce and secrete natural antifouling compounds before the biofouling species are able to establish themselves on the aquaculture substrate, thus contributing to the anti-biofouling properties in addition to the fibrillated submicron surface structure of the low-porosity substrate.

[0089] Selective nanostructuring can be achieved, for example, by providing a combination of interfibril distance, substrate porosity and depth of the fibrillated submicron surface structure that supports the attachment and growth of targeted seaweed species while inhibiting or preventing the attachment and growth of biofouling species.

[0090] Good settlement and attachment are important for successful cultivation of seaweed crops. Juvenile plants must be attached firmly enough so that they do not detach from the culture substrate in the extreme exposure of the open ocean. All juvenile seaweeds have a tendency to inhibit biofouling, which is often caused by the overgrowth of other algal species such as diatoms, filamentous brown algae, and green algae. Biofouling problems are most common on farms when first set up, and although biofouling can occur on farms during seed production, it is often small enough to pose a suffocation hazard. An ideal culture substrate provides reliable attachment of the target species while inhibiting the growth of biofouling organisms.

[0091] The fibrillated submicron surface structure of the low porosity substrates described herein supports such strong attachment and growth of seaweed while inhibiting biofouling. FIG. 4 shows a juvenile kelp plant 400 attached to a low porosity substrate 450 having a fibrillated submicron surface structure. The juvenile kelp plant 400 is attached to the low porosity substrate 450 via an anchoring device 410, which appears as a network of projections emanating from the base of the juvenile kelp plant 400. Such attachment was observed when kelp, nori, and dulse were seeded and grown, respectively, on low porosity substrates having a fibrillated submicron surface structure according to some embodiments, as shown in the two samples on the left in each of FIGS. 5, 6, and 7. Conversely, low porosity substrates lacking a fibrillated submicron surface structure failed to retain seaweed, as shown in the two samples on the right in each of FIGS. 5, 6, and 7. The surface structure of a low porosity substrate lacking a fibrillated submicron surface structure is shown by Figures 3A-3D. Figures 3A-3D are SEM micrographs showing the surface structure of a low porosity ePTFE substrate lacking surface node and fibril nanostructure. Figures 3A-3C show the surface structure on a first side of the low porosity substrate at increasing magnification. The scales presented are 100 μm (Figure 3A), 10 μm (Figure 3B) and 5 μm (Figure 3C). Figure 3D shows the surface structure of a second side of the low porosity substrate (provided at a scale of 5 μm). At the lowest magnification (Figure 3A), the surface of the low porosity substrate appears nearly smooth, similar to the surface of the low porosity substrate shown in Figure 2A. At higher magnifications, it is clear that the substrate lacks a fibrillated submicron surface structure (Figures 3B-3D).

[0092] In certain embodiments, the aquaculture substrate comprises a high porosity substrate in addition to a low porosity substrate. In certain embodiments, the high porosity substrate has a node and fibril microstructure characterized by a porosity of at least 30% and an average interfibril distance of about 1 μm to about 500 μm, or an average pore size of about 1 μm to about 500 μm. The high porosity substrate can function, for example, to intersperse the low porosity substrate, help control the localization of seaweed on the low porosity substrate, and deliver nutrients to the growing seaweed. In some embodiments, the high porosity substrate can retain and support spore growth (e.g., retain and support algal spores and the growth of mature seaweed therefrom) and / or inhibit or prevent the retention of spores and / or biofouling organisms. Whether the high porosity retains and supports spore growth or inhibits such retention depends on the properties of the high porosity substrate, such as porosity and interfibril distance.

[0093] In some embodiments, the highly porous substrate has a microstructure comprising a plurality of fibrils that define an average inter-fibril distance. Figure 8 is an SEM micrograph showing the microstructure 100 of a highly porous substrate comprising a fibrillated material according to some embodiments. The fibrillated material having the microstructure 800 shown in Figure 1 is expanded polytetrafluoroethylene (ePTFE). As shown, the microstructure 800 is defined by a plurality of fibrils 802 that interconnect nodes 804. The fibrils 802 define inter-fibril spaces 803.

[0094] The fibrils 803 have a defined average interfibril distance, and in some embodiments, the average interfibril distance is about 1 μm to about 500 μm, 1 μm to about 200 μm, about 1 μm to about 50 μm, about 1 μm to about 20 μm, about 1 μm to about 10 μm, about 1 μm to about 5 μm, about 5 μm to about 50 μm, about 5 μm to about 20 μm, about 5 μm to about 10 μm, about 10 μm to about 100 μm, about 10 μm to about 75 μm, about 10 μm to about It can be 50 μm, about 10 μm to about 25 μm, about 25 μm to about 200 μm, about 25 μm to about 150 μm, about 25 μm to about 100 μm, about 25 μm to about 50 μm, about 50 μm to about 200 μm, about 50 μm to about 150 μm, about 50 μm to about 100 μm, about 100 μm to about 200 μm, about 100 μm to about 150 μm, about 150 μm to about 200 μm, or about 200 μm to about 500 μm. In some embodiments, the fibrils 802 can have an average interfibril distance of about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 10 μm, about 20 μm, about 30 μm, about 40 μm, about 50 μm, about 60 μm, about 70 μm, about 80 μm, about 90 μm, about 100 μm, about 110 μm, about 120 μm, about 130 μm, about 140 μm, about 150 μm, about 160 μm, about 170 μm, about 180 μm, about 190 μm, about 200 μm, about 300 μm, about 400 μm, or about 500 μm.

[0095] Figure 9 is a high magnification SEM micrograph of the microstructure shown in Figure 8. Figure 9 shows the dimensions of selected interfibrillar spaces 803 in μm.

[0096] FIG. 10 is a SEM micrograph showing another microstructure of a highly porous substrate comprising fibrillated ePTFE material according to some embodiments.

[0097] FIG. 11 is a high magnification SEM micrograph of the microstructure shown in FIG.

[0098] In some embodiments, at least a portion of the fibrils 802 are spaced apart sufficiently to retain spores in the interfibrillar spaces 802. In other embodiments, the fibrils 802 are spaced apart sufficiently to inhibit or prevent retention of spores in the interfibrillar spaces 802.

[0099] 12 is a perspective view of a schematic diagram of a microstructure of an aquaculture substrate, according to some embodiments. As shown, the microstructure 1200 is defined by a plurality of pores 1202.

[0100] The pores 1202 can be circular, nearly circular, or elliptical. The pores 1202 can be about 1 μm to about 500 μm, 1 μm to about 200 μm, about 1 μm to about 50 μm, about 1 μm to about 20 μm, about 1 μm to about 10 μm, about 1 μm to about 5 μm, about 5 μm to about 50 μm, about 5 μm to about 20 μm, about 5 μm to about 10 μm, about 10 μm to about 100 μm, about 10 μm to about 75 μm, about 10 μm to about 50 μm, about 10 μm to about 25 μm, about 25 μm The diameter or approximate diameter of the nanoparticles may be about 200 μm, about 25 μm to about 150 μm, about 25 μm to about 100 μm, about 25 μm to about 50 μm, about 50 μm to about 200 μm, about 50 μm to about 150 μm, about 50 μm to about 100 μm, about 100 μm to about 200 μm, about 100 μm to about 150 μm, about 150 μm to about 200 μm, or about 200 μm to about 500 μm. In some embodiments, the pores 1202 can have a diameter or approximate diameter of about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 10 μm, about 20 μm, about 30 μm, about 40 μm, about 50 μm, about 60 μm, about 70 μm, about 80 μm, about 90 μm, about 100 μm, about 110 μm, about 120 μm, about 130 μm, about 140 μm, about 150 μm, about 160 μm, about 170 μm, about 180 μm, about 190 μm, about 200 μm, about 300 μm, about 400 μm, or about 500 μm.

[0101] In some embodiments, the interfibril spaces 803 of Figure 8 form the pores 1202 of Figure 12. That is, a microstructure 800 having a plurality of fibrils 802 can form a porous microstructure 1200. However, not all microstructures 1200 having pores 1202 are fibrillated.

[0102] In some embodiments, the microstructure of the highly porous substrate is configured to retain spores and sporophytes, gametophytes, or other organisms grown from the retained spores. In some embodiments, the microstructure is configured to retain algal spores, algal sporophytes and / or gametophytes, plant spores, seedlings, bacterial endospores, fungal spores, or combinations thereof. In some embodiments, the culture substrate retains a plurality of spores and / or organisms grown therefrom (e.g., sporophytes and / or gametophytes). The plurality of spores and / or organisms may all be of the same type, or may be of two or more different types. In some embodiments, the highly porous substrate retains the same type of seaweed spores and / or seaweed as that seeded and attached onto the low-porosity substrate. In other embodiments, the highly porous substrate retains a different type of seaweed spores and / or seaweed as that seeded and attached onto the low-porosity substrate. In some embodiments, the culture substrate retains two different spore types that exhibit a symbiotic relationship when cultured or grown together. For simplicity, throughout this disclosure, reference will be made to "spores" in reference to low-porosity substrates, however, gametophytes, sporophytes, seedlings or other organisms grown from spores are also contemplated by this term and are considered to be within the scope of this disclosure.

[0103] In some embodiments, in addition to retaining the spores, the highly porous substrate promotes germination and growth therefrom of the retained spores, i.e., the highly porous substrate maintains the retained spores viable, hi certain embodiments, the microstructures are configured to permanently immobilize at least a portion of the spores.

[0104] For example, the highly porous substrate creates a microenvironment that is conducive to germination and growth of the retained spores. In some embodiments, the microstructure is initially in a first retention stage where the microstructure functions to retain and maintain the target spores. The microstructure is then in a second growth stage where germination of the spores is induced, and ingrowth of sporophytes (e.g., sporophytes, gametophytes, seedlings, etc.) from the spores occurs on and / or into the microstructure, thereby resulting in mechanical bonding or fixation of the sporophytes to the microstructure. Thus, in some embodiments, the microstructure is configured to non-removably fix the germinated spores, preventing loss of the germinated spores, for example, during transportation or placement in an aquaculture facility (e.g., in an open water environment), or loss to environmental factors (e.g., currents).

[0105] In certain embodiments, the highly porous substrate creates a selective microenvironment that is conducive to the germination and growth of target spores while inhibiting or preventing the germination, growth and / or proliferation of non-target spores or other cells. A selective microenvironment can be achieved, for example, by providing a combination of inter-fibril distance and / or pore size, material density, ratio of inter-fibril distance to average density of the material, depth or thickness, hydrophobicity, and the presence or absence of nutrients, moisture, bioactive agents, and adhesives that support the germination and growth of target spores while inhibiting or preventing the germination, growth and / or proliferation of non-target spores or other cells.

[0106] Several factors can affect the retention and / or survival of spores and the organisms grown therefrom, including, for example, interfibril distance and / or pore size, material density, ratio of interfibril distance to average density of the material, depth or thickness, hydrophobicity, and the presence or absence of nutrients, moisture, bioactive agents, and adhesives. Each of these factors is described in more detail below.

[0107] The distance between the two fibrils (i.e., the interfibril distance) defines an interfibril space 803. In some embodiments, the interfibril space 803, and thus the interfibril distance, is sufficient to retain the spores therein, and the spores are retained between the two fibrils that define the interfibril space. The interfibril distance is sufficient to allow at least a portion of the spores to enter between the two fibrils that define the interfibril space 803. In some embodiments, the spores are thereby retained within the microstructure of the aquaculture substrate. FIG. 13 is a modified version of the photograph of FIG. 9, showing the microstructure of a highly porous substrate including fibrillated material and covered with representative spores having diameters of either about 10 μm (e.g., nori and kelp spores) or about 30 μm (e.g., dulse spores). FIG. 13 shows how and where a target spore can enter between two fibrils that define an interfibrillar space.

[0108] In some embodiments, the average inter-fibril distance of the highly porous substrate is controlled to facilitate the entry of at least some of the spores into the microstructure. For example, if it is desired for the microstructure to hold dulse (Palmaria palmata) spores having a diameter of about 30 μm, the average inter-fibril distance of the highly porous substrate microstructure is about 30 μm or slightly larger (e.g., about 32 μm to about 35 μm). If it is desired for the highly porous microstructure to hold nori or kombu spores, each spore having a diameter of about 10 μm, the average inter-fibril distance of the microstructure is about 10 μm or slightly larger (e.g., about 12 μm to about 15 μm). In some embodiments, it may be desirable to hold spores of multiple species (e.g., dulse, nori, and kombu). In such embodiments, the average inter-fibril distance is sufficient to allow at least some of the spores of the multiple species to enter and be held in the inter-fibril spaces. In some embodiments, the target spores have a diameter of about 0.5 μm to about 200 μm.

[0109] In some embodiments, about half of the target spores can enter the interfibrillar spaces 803 in the highly porous substrate. In such embodiments, the interfibrillar distance is at least equal to a dimension (e.g., diameter or width) of the target spores. In some embodiments, the interfibrillar distance is slightly greater than a dimension of the target spores. This allows the entire spores to enter and be retained in the interfibrillar spaces 803.

[0110] In some embodiments, more than half of the target spores, up to the entire spore, can enter the interfibrillar spaces 803 of the highly porous substrate. In such embodiments, the portion of the spores that enter the interfibrillar spaces 803 can be governed by the depth of the pores, the openings of which are defined by the interfibrillar spaces. The depth of the pores can be controlled, for example, by the material density.

[0111] In some embodiments, only a portion of the spores enter the interfibrillar spaces 803 of the highly porous substrate. Thus, if the interfibrillar distance is smaller than the diameter of the target spore, the target spores can only partially enter the interfibrillar spaces 803. If the target spores only partially enter the interfibrillar spaces 803, the spores may still be retained there if a sufficient portion of the target spores enter the interfibrillar spaces 803. In some embodiments, a substance such as an adhesive applied to the microstructure reduces the portion of the spores required to enter the interfibrillar spaces 803 and aids retention.

[0112] In some embodiments, the microstructure of the highly porous substrate is formed by non-fibrillated materials. In certain embodiments, the pore openings 1202 are inherent to the material of the culture substrate. It will be appreciated that different materials may have different pore opening characteristics, and materials can be manufactured or otherwise engineered to provide the desired pore opening characteristics. In other embodiments, the pore openings 1202 are formed by microdrilling techniques, such as mechanical microdrilling, e.g., ultrasonic drilling, powder blasting, or abrasive water jet machining (AWJM), thermal microdrilling, e.g., laser machining, wet etching, chemical microdrilling, including deep reactive ion etching (DRIE) or plasma etching, hybrid microdrilling techniques, e.g., spark-assisted chemical engraving (SACE), vibration-assisted micromachining, laser-induced plasma micromachining (LIPMM), water-assisted micromachining, etc.

[0113] In embodiments where the microstructure of the highly porous substrate is formed by a non-fibrillated material, the pore openings 1202 act in much the same manner as the interfibrillar spaces 103 described above and are of sufficient size to allow at least some of the target spores to enter the pore openings 1202. In some embodiments, the spores are thereby retained within the microstructure of the culture substrate. In some embodiments, the size of the pore openings 1202 is controlled to facilitate the entry of at least some of the target spores into the microstructure. For example, if it is desired that the microstructure of the highly porous substrate retain dulse (Palmaria palmata) spores having a diameter of about 30 μm, the pore openings 1202 of the microstructure have a diameter of about 30 μm or slightly larger (e.g., about 32 μm to about 35 μm). In some embodiments, the target spores have a diameter of about 0.5 μm to about 200 μm.

[0114] In some embodiments, approximately half of the target spores can enter the pore openings 1202 of the highly porous substrate. In such embodiments, the pore openings are at least equal to the dimensions (e.g., diameter or width) of the target spores. In some embodiments, the pore openings are slightly larger than the dimensions of the target spores. This allows the entire spores to enter the pore openings 1202 and be retained therein.

[0115] In some embodiments, more than half of the target spores, up to the entire spore, can enter the highly porous substrate pore openings 1202. In such embodiments, the fraction of the spores that enter the pore openings 1202 can be governed by the pore depth, which can be controlled, for example, by the material density.

[0116] In some embodiments, only a portion of the spore enters the pore opening 1202. Thus, if the pore opening is smaller than the diameter of the target spore, the target spore can only partially enter the pore opening 1202. In the case where the spore only partially enters the pore opening 1202, when a sufficient portion of the target spore enters the pore opening, the target spore may still be retained therein. In some embodiments, a substance such as an adhesive applied to the microstructure can reduce the portion of the spore required to enter the pore opening 1202 and aid in retention.

[0117] In some embodiments, the highly porous substrate is a low density material. The low density material may be fibrillated or non-fibrillated and in some embodiments defines the microstructure of the aquaculture substrate. The low density material has a density of about 0.1 g / cm 3 , about 0.2g / cm 3 , about 0.3g / cm 3 , about 0.4g / cm 3 , about 0.5g / cm 3 , about 0.6g / cm 3 , about 0.7g / cm 3 , about 0.8g / cm 3 , about 0.9g / cm 3 or about 1.0 g / cm 3In some embodiments, the density of the low density material can be about 0.1 g / cm 3 ~Approx. 1g / cm 3 It is.

[0118] In some embodiments, the low density material provides sufficient pore depth to retain spores in the interfibrillar spaces 803 or pore openings 1202.

[0119] In some embodiments, the dimensions of the pore opening (length (μm) and width (μm)), along with the depth (μm) to which the target spores enter the pore, whether formed by fibrillated or non-fibrillated material, dictate the capture rate. Each spore type may have a different capture rate required for proper retention of the spores by the microstructure of the highly porous substrate. The required capture rate may be influenced by the properties of the materials that make up the microstructure of the highly porous substrate and the presence or absence of nutrients, adhesives and / or bioactive agents.

[0120] In some embodiments, the low density material allows spores to germinate and grow into the low density material. For example, when dulse spores held in the low density material having the microstructure described herein develop into gametophytes and then sporophytes, the dulse grows into the low density material in all three dimensions (i.e., horizontally in the x and y dimensions and in depth in the z dimension). This three-dimensional growth can improve the retention of dulse gametophytes and sporophytes.

[0121] Figures 14A and 14B are cross-sectional SEM micrographs taken at two different magnifications of a low-density highly porous microstructured material according to some embodiments, showing three-dimensional ingrowth of dulse seaweed into the low-density material, and Figure 14C is a cross-sectional micrograph produced using optical fluorescence microscopy showing ingrowth of dulse seaweed into the low-density material.

[0122] Figure 15 (top panel) is an SEM micrograph of the surface of a low density, highly porous microstructured material according to some embodiments, and Figure 15 (bottom panel) shows the same aquaculture substrate material as the top panel, subsequently seeded with sugar kelp spores and allowed to germinate.

[0123] Figure 16 shows SEM micrographs of the microstructured surface taken at two different magnifications, where it is clear to see that dulse seaweed has attached to and grown into the microstructure. Figure 17 shows a fluorescent micrograph of the microstructured surface with dulse seaweed attached and growing into the microstructure. The seaweed growth is observed growing into the microstructure in a "growth network" in all three dimensions.

[0124] From the micrographs in Figures 14A-17, it is clear that dulse seaweed is able to grow within the microstructure of the fibrillated highly porous ePTFE substrate in all three dimensions and the seaweed can be securely anchored within the microstructure.

[0125] In some embodiments, the germinated spores grow deep into the microstructure of the highly porous substrate. This deep ingrowth and incorporation into the microstructure provides the added benefit of protecting the germinated spores from the external environment (e.g., the ocean and its currents in the case of seaweed gametophytes). In some embodiments, the penetration depth of the germinated spores relative to the initial size of the spores is about 1:1 to about 200:1. For example, for a dulse spore with an initial diameter of about 30 μm, the dulse spores can grow to a depth of about 30 μm to about 6 mm within the microstructure.

[0126] In some embodiments, the low density highly porous material has a thickness sufficient to allow a desired level of ingrowth. In some embodiments, the aquaculture substrate comprises a single layer of low density material. In some embodiments, the aquaculture substrate comprises two or more layers of low density material. In certain embodiments, the two or more layers are present in a laminate, i.e., a laminate of multiple layers of low density material.

[0127] In some embodiments, the interfibrillar distance and density of the microstructured highly porous material is determined by the average density (g / cm) of the fibrillated material. 3 In some embodiments, the ratio of the average interfibril distance (μm) to the average density (g / cm 3 ) is about 1:1, about 10:1, about 20:1, about 30:1, about 40:1, about 50:1, about 60:1, about 70:1, about 80:1, about 90:1, about 100:1, about 125:1, about 150:1, about 175:1, about 200:1, about 225:1, about 250:1, about 275:1, about 300:1, about 325:1, about 350:1, about 375:1, about 400:1, about 425:1 , about 450:1, about 475:1, about 500:1, about 550:1, about 600:1, about 650:1, about 700:1, about 750:1, about 800:1, about 900:1, about 1000:1, about 1250:1, about 1500:1, about 1750:1, or about 2000:1. In some embodiments, the average density (g / cm) of the fibrillated material may be about 450:1, about 475:1, about 500:1, about 550:1, about 600:1, about 650:1, about 700:1, about 750:1, about 800:1, about 900:1, about 1000:1, about 1250:1, about 1500:1, about 1750:1, or about 2000:1. 3 The ratio of the average interfibril distance (μm) to the average interfibril distance (μm) is about 1:1 to about 2000:1.

[0128] In some embodiments, the culture substrate (i.e., the low porosity substrate, the high porosity substrate, or both) comprises one or more adhesives. The adhesives are applied to the surface of the fibrillated submicron surface structure of the low porosity substrate or the microstructure of the high porosity substrate and are absorbed into the low porosity substrate or the high porosity substrate, or are applied to both the surface of the fibrillated submicron surface structure of the low porosity substrate or the microstructure of the high porosity substrate and are absorbed into the low porosity substrate or the high porosity substrate. In some embodiments, the adhesives comprise one or more cell adhesive ligands specific for spores retained by the culture substrate.

[0129] In some embodiments, the aquaculture substrates described herein (i.e., low porosity substrates, high porosity substrates, or both) include a nutrient phase associated with at least a portion of the aquaculture substrate. The nutrient phase serves to maintain viable spores, germinated spores, and growing organisms (e.g., juvenile seaweed) retained by the aquaculture substrate. In some embodiments, the nutrient phase promotes germination and growth therefrom of spores retained within the microstructure of the high porosity substrate. In some embodiments, the nutrient phase acts to maintain and / or promote attachment to the low porosity substrate and / or the high porosity substrate, or to maintain and / or promote ingrowth or integration into the microstructure of the high porosity substrate.

[0130] In some embodiments, the nutrient phase acts as a chemical attractant that can attract spores or juvenile organisms (e.g., algal sporophytes and / or gametophytes) to a predetermined location in the aquaculture substrate to which the nutrient phase is applied or contained.

[0131] The nutrient phase can be included as a filler in the low porosity substrate, on the fibrillated submicron surface structure of the low porosity substrate, in the microstructure of the high porosity substrate, on the microstructure of the high porosity substrate (e.g., on the surface thereof), or any combination thereof. In some embodiments, the nutrient phase is applied to the surface of the aquaculture substrate as a coating. In some embodiments, the nutrient phase is included within one or more materials forming the aquaculture substrate. When the nutrient phase is included within the material forming the low porosity substrate, the nutrient phase can promote attachment and robust growth. When the nutrient phase is included within the material forming the high porosity substrate, the nutrient phase can promote ingrowth or integration into the microstructure. By promoting seaweed growth, the nutrient phase can assist in preventing biofouling, as healthy, fast-growing seaweed is known to produce and release its own natural antifouling compounds.

[0132] In some embodiments, the nutrient phase includes at least one nutrient that is beneficial to the target seaweed species and / or target spores such that the resulting germinated spores will adhere to or be retained by the cultivation substrate. For example, when dulse seaweed adheres to the fibrillated submicron surface structure of a low porosity substrate or is retained by the microstructure of a high porosity substrate, the nutrient phase includes macronutrients (e.g., nitrogen, phosphorus, carbon, etc.), micronutrients (iron, zinc, copper, manganese, molybdenum, etc.), and vitamins (vitamin B). 12 Nutrients in the vegetative phase can include nutrients such as ammonium nitrate (NH), thiamine, and biotin, which support the growth and health of germinated dulse spores. Nutrients in the vegetative phase can be provided in a variety of forms. For example, nitrogen can be provided in the form of ammonium nitrate (NH 4 NO 3 ), ammonium sulfate ((NH 4 ) 2 SO 4 ), calcium nitrate (Ca(NO 3 ) 2 ), potassium nitrate (KNO 3 ), urea (CO(NH 2 ) 2 ) etc. It will be recognized by those skilled in the art what nutrients would be beneficial to include in the nutrient phase to keep the spores viable and the resulting germinated spores retained by the culture substrate.

[0133] Since different spore types, germinated spores and growth organisms (e.g. seaweed) have different nutrient requirements, the nutrients included in the nutrient phase depend on which spores are held by the cultivation substrate. The choice of nutrients also depends on the intended use of the cultivation system. For example, if the cultivation substrate holding the spores, germinated spores and / or growth organisms is introduced into an environment lacking essential nutrients, all necessary nutrients can be included in the nutrient phase. If the cultivation substrate holding the spores / germinated spores / growth organisms is introduced into an environment that has at least one essential nutrient, those environmentally available essential nutrients can be excluded from the nutrient phase or included at a lower concentration. The cultivation substrate can also act to concentrate nutrients from the environment, for example, by trapping environmental nutrients within the microstructure of the highly porous substrate. This can be advantageous in environments where environmental nutrients are only present in low concentrations.

[0134] In some embodiments, the aquaculture system can be used to transport the retained spores / germinated spores from one location to another, as further described elsewhere herein. When the aquaculture system functions as a transport system, the nutrient phase can include nutrient levels sufficient to support the viability of the retained spores / germinated spores / growth organisms during transport. In some embodiments, the nutrient phase can include nutrient levels sufficient to maintain the retained spores / germinated spores / growth organisms viable after transport, after the retained spores / germinated spores / growth organisms are introduced into a new environment (e.g., open water).

[0135] In some embodiments, the nutrient phase includes one or more carriers. Carriers can include, for example, liquid carriers, gel carriers, and hydrogel carriers. In some embodiments, the nutrient phase carrier is an adhesive. Including an adhesive as a nutrient phase carrier can function to ensure that the nutrient phase remains on and / or in the culture substrate. When the nutrient phase is applied to the surface of the culture substrate and includes an adhesive as a carrier, the nutrient surface can also function to promote attachment to the culture substrate.

[0136] In some embodiments, the nutrient phase is formulated to control the release rate of the nutrients.

[0137] In some embodiments, the culture substrate further comprises a salt associated with the culture substrate. In some embodiments, the salt is sodium chloride (NaCl). The salt associated with the culture substrate can create and maintain a saltwater microenvironment for the retained spores / germinated spores. This can be particularly advantageous when seaweed and marine plants are retained by the culture substrate. In some embodiments, a saltwater microenvironment can be maintained within the culture substrate when the culture substrate is submerged in fresh water, thereby keeping the marine species viable and avoiding the need to maintain a saltwater culture environment, which can be difficult and expensive.

[0138] In some embodiments, the aquaculture substrate comprises a liquid-containing phase associated with at least a portion of the aquaculture substrate, which serves to provide and maintain moisture within the microenvironment of the highly porous substrate's microstructure, which can serve to maintain viability of spores / germinated spores / growing organisms carried by the aquaculture substrate.

[0139] In some embodiments, the culture substrate comprises a liquid wicking material. The liquid wicking material can be the same material that forms the low porosity substrate and / or the high porosity substrate. The liquid wicking material functions to maintain moisture within the microenvironment of the culture substrate.

[0140] While spores and endospores can be maintained viably in dry environments, germinated spores and growth organisms (e.g., juvenile seaweed) generally require moisture to grow and / or multiply. By maintaining a moist microenvironment (e.g., by including a liquid-containing substrate and / or liquid-wicking material), it may be possible to transport an aquaculture system with spores / germinated spores / growth organisms retained therein and / or thereon without having to maintain the aquaculture system in an aqueous environment.

[0141] In some embodiments, the liquid-containing phase is entrained in the low porosity substrate, on the fibrillated submicron surface structure of the low porosity substrate, within the microstructure of the high porosity substrate, on (e.g., on) the microstructure of the high porosity substrate, or any combination thereof. In some embodiments, the liquid-containing phase is applied to the surface of the aquaculture substrate as a coating. In some embodiments, the liquid-containing phase is contained within one or more materials forming the aquaculture substrate.

[0142] In some embodiments, the liquid-containing phase comprises, for example, a hydrogel, a slurry, a paste, or a combination of a hydrogel, a slurry, and / or a paste. In some embodiments, the liquid-containing phase is a carrier for the nutritional phase.

[0143] In some embodiments, at least a portion of the aquaculture substrate is hydrophilic, and such hydrophilic portions of the aquaculture substrate may contribute to retention by and / or attachment to the aquaculture substrate.

[0144] In some embodiments, at least a portion of the culture substrate is hydrophobic. Such hydrophobic portions of the culture substrate can reduce or prevent or resist retention and / or attachment of spores / germinating spores / growing organisms. This can be useful in reducing or preventing biofouling and attachment of undesirable spores or other cells or organisms to the culture substrate.

[0145] In some embodiments, one or more portions of the culture substrate are hydrophobic and one or more portions of the culture substrate are hydrophilic, whereby the spores / germinated spores / grown organisms are encouraged to be preferentially retained or attached by one or more hydrophilic portions of the culture substrate.

[0146] In some embodiments, the aquaculture substrate can include one or more bioactive agents associated with the aquaculture substrate. Bioactive agents include any agent that has a positive or negative effect on cells or organisms that come into contact with the agent. Suitable bioactive agents can include, for example, biocides and serum. Biocides can be associated with portions of the aquaculture substrate to prevent attachment and growth of undesirable cells or organisms on those portions of the aquaculture substrate. Undesirable cells can include, for example, non-target cells (i.e., biofouling species), such as bacteria, yeast, and algae. Biocides can also deter pests, such as insects. In some embodiments, biocides prevent attachment and growth of target spores on portions of the aquaculture substrate where attachment and growth is not desired. In some embodiments, serum can be applied to portions of the aquaculture substrate. The serum can aid in the attachment and retention of spores and / or promote germination or growth from spores. The serum can include, for example, cell adhesive ligands and can also provide a source of growth factors, hormones, and attachment factors.

[0147] In some embodiments, the culture substrate is patterned. Patterning the culture substrate can specify areas of the culture substrate to which the target spores / germinating spores / growth organisms (e.g., juvenile seaweed) will attach. In some embodiments, the culture substrate includes a pattern of sections of low porosity substrate and sections of high porosity substrate. In some embodiments, the culture substrate is patterned in a "checkerboard" fashion with alternating sections of low porosity substrate and high porosity substrate. The pattern of low porosity substrate and high porosity substrate can be an organized or selective pattern, or a random pattern. The sections of the substrate can all be the same size or different sizes. The sections of one of the low porosity substrate or the high porosity substrate can be the same size but different from the other (i.e., all sections of the low porosity substrate are the same size but different sizes from the sections of the high porosity substrate).

[0148] In some embodiments, the fibrillated submicron surface structure of the low porosity substrate and / or the microstructure of the high porosity substrate are patterned. By specifically patterning the fibrillated submicron surface structure, the microstructure, or both, it is possible to specifically retain target spores in the represented portions of the microstructure while excluding cells from other portions.

[0149] In some embodiments, the fibrillated sub-micron surface structure comprises a pattern of different surface structures. For example, the average inter-fibril distance can vary across the aquaculture substrate. In some embodiments, the low porosity substrate comprises a pattern of areas with high inter-fibril distance and areas with low inter-fibril distance. In such embodiments, the differences in inter-fibril distance can promote attachment and fixation development of different seaweed species. In other embodiments, some areas of the fibrillated sub-micron surface structure can be removed, leaving a smooth surface to which seaweed cannot attach. In such embodiments, this allows control over where seaweed attaches on the aquaculture substrate, particularly on low porosity substrates.

[0150] In some embodiments, the depth of the fibrillated submicron surface structures may vary across the aquaculture substrate. In some embodiments, the low porosity substrate comprises a pattern of greater and lesser fibrillated submicron surface structure depths. In such embodiments, the differences in the depth of the fibrillated submicron surface structures may promote attachment and fixation development of different seaweed species.

[0151] In certain embodiments, both the interfibrillar distance and the depth of the fibrillated submicron surface structure can be varied, and in such embodiments, the fibrillated submicron surface structure can be fine-tuned for a given application.

[0152] In some embodiments, the microstructure of the highly porous substrate included in the culture substrate includes a pattern of high and low density portions. In such a configuration, the low density portions correspond to portions of the microstructure configured to retain and keep the target spores viable, while the high density portions inhibit or prevent cell retention. The density pattern can span any dimension. For example, the high / low density pattern can span the x or y dimension of the culture substrate, or the z dimension. When spanning the z dimension, the outermost portions generally become the low density portions configured to retain and keep the target spores viable. The underlying portions may be denser than the outermost portions, or may be even less dense. If the underlying portions are denser, the ingrowth of germinated spores is inhibited or prevented. If the underlying portions are less dense than the outermost portions, the ingrowth of germinated spores is promoted and / or facilitated. In some embodiments, the density pattern or gradient in the z dimension results from concentric wraps of microstructured materials with different densities, or from a laminate configuration in which each lamina has a different density. In some embodiments, the density pattern can extend in two or all three dimensions, hi some embodiments, portions of the microstructure have a density gradient.

[0153] Density can be measured in a variety of ways, including, for example, measuring the dimensions and weight of the material. Additionally, wetting experiments can be performed to derive density values. Density can be altered, for example, by altering the interfibril distance, the number of fibrils per unit volume, the number of pores per unit volume, and the pore size.

[0154] In some embodiments, the density of the highly porous substrate is the density of the material itself that forms the highly porous substrate, i.e., without any inclusions such as a nutrient phase, liquid-containing phase, etc.

[0155] In some embodiments, the density of the highly porous substrate is the density of the material of the highly porous substrate and its contents, such as a nutrient phase, a liquid-containing phase, or a density-modifying filler. In some embodiments, portions of the microstructure are filled with a filler to change the density, thereby changing the ability of that portion of the microstructure to retain spores and / or prevent ingrowth into the microstructure of the highly porous substrate.

[0156] In some embodiments, the highly porous substrate has a pattern of highly porous and less porous portions. In some embodiments, the less porous portions correspond to portions of the highly porous substrate configured to retain and maintain viability of the target spores. In some embodiments, the highly porous portions correspond to portions of the microstructure configured to retain and maintain viability of the target spores.

[0157] In some embodiments, the highly porous substrate comprises a pattern of areas with greater inter-fibril distances and areas with less inter-fibril distances. In some embodiments, the areas with less inter-fibril distances correspond to areas of the microstructure configured to retain and keep spores viable. In such embodiments, the areas with greater inter-fibril distances have an inter-fibril distance that is too great to retain target spores. In other embodiments, the areas with greater inter-fibril distances correspond to areas of the microstructure configured to retain and keep spores viable. In such embodiments, the areas with less inter-fibril distances have an inter-fibril distance that is too small to retain target spores.

[0158] In some embodiments, the pattern of the highly porous substrate is generated by controlling at least two of density, porosity, and average interfibril distance. In some embodiments, the pattern of the highly porous substrate may be an organized or selective pattern, or a random pattern, whether including density, porosity, average interfibril distance, or a combination thereof.

[0159] In some embodiments, the pattern of the highly porous substrate can be set or adjusted by selectively applying longitudinal tension. Setting or adjusting the pattern by applying longitudinal tension can mechanically alter the pattern. In some embodiments, the pattern is set or adjusted in the fibrillated highly porous material by selectively applying longitudinal tension.

[0160] In some embodiments, the patterned highly porous substrate comprises portions having two or more properties that are favorable for spore retention. For example, the patterned highly porous substrate may comprise a low density (i.e., less than about 1.0 g / cm 3 The fibril spacing may be selected to retain target spores. These same portions may further be hydrophilic and / or include one or more of a vegetative phase, an adhesive, and a bioactive agent. For example, the density, interfibril spacing, hydrophobicity, vegetative phase, adhesive, and bioactive agent may each be selected to preferentially retain target spores.

[0161] In some embodiments, the aquaculture substrate is configured as a fiber, a membrane, a woven article, a nonwoven article, a braided article, a fabric, a knitted article, a particle dispersion, or a combination thereof.

[0162] In some embodiments, the aquaculture system includes at least one of a backer layer, a carrier layer, a laminate of multiple layers, a composite material, or a combination thereof. The aquaculture substrate (i.e., low porosity substrate and / or high porosity substrate) can be deposited on the backer layer or carrier layer or included in the laminate. The backer layer can be, for example, a rope or a metal cable. For example, if the aquaculture substrate holds seaweed spores and keeps them viable, the aquaculture substrate can be deposited on the rope or metal cable to produce a seed rope, eliminating the need to wrap a seed string around the rope in aquaculture farms for open water rope culture of seaweed.

[0163] In some embodiments, the cultivation substrate has sufficient strength to be moved as a conveyor belt through the various stages of growth of the retained spores, including harvesting of the germinated spores. In some embodiments, the cultivation substrate is deposited on a backer layer, a carrier layer, or fabricated into a laminate to create an aquaculture system that has sufficient strength to be moved as a conveyor belt through the various stages of growth of the retained spores, including harvesting of the germinated spores.

[0164] In some embodiments, the aquaculture substrate is configured as a particle dispersion. The fibrillated submicron surface structure of the low porosity substrate and the microstructure of the high porosity substrate are provided by a plurality of particles in the dispersion that are formulated to be deposited, when pre-established, onto a backer layer or carrier substrate to form an aquaculture system. The particles can be, for example, chopped or otherwise fragmented pieces of fibers, membranes, woven articles, nonwoven articles, braided articles, fabrics, or knitted articles having a fibrillated submicron surface structure or microstructure as described herein. In some embodiments, the spores are contacted with the particles before deposition onto the backer layer or carrier substrate. In other embodiments, the spores are contacted with the particles after deposition onto the backer layer or carrier substrate. The particle dispersion can be deposited onto the backer layer or carrier substrate, for example, by spraying, dip coating, brushing, or other coating means. In embodiments in which the spores are contacted with the particles before deposition onto the backer layer or carrier substrate, care must be taken to ensure that the deposition method does not adversely affect the retained spores. Spores and endospores are more resilient and can withstand deposition in such a manner.

[0165] In some embodiments, the aquaculture substrate comprises an expanded (expanded, expanded, stretched or foamed) fluoropolymer. In some embodiments, the expanded fluoropolymer is selected from the group of expanded fluorinated ethylene propylene (eFEP), porous perfluoroalkoxyalkane (PFA), expanded ethylene tetrafluoroethylene (eETFE), expanded vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene polymer (eVDF-co-(TFE or TrFE)), expanded polytetrafluoroethylene (ePTFE), and modified ePTFE. Examples of suitable expanded fluoropolymers include fluorinated ethylene propylene (FEP), porous perfluoroalkoxyalkanes (PFA), polyestersulfones (PES), poly(p-xylylene) (ePPX) as taught in U.S. Patent Application Publication No. 2016 / 0032069, ultra-high molecular weight polyethylene (eUHMWPE) as taught in U.S. Patent No. 9,926,416 to Sbriglia, ethylene tetrafluoroethylene (eETFE) as taught in U.S. Patent No. 9,932,429 to Sbriglia, polylactic acid (ePLLA) as taught in U.S. Patent No. 7,932,184 to Sbriglia et al., vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene [VDF-co-(TFE or TrFE)] polymers as taught in U.S. Patent No. 9,441,088 to Sbriglia.

[0166] In some embodiments, the expanded fluoropolymer includes a nutrient phase, which can be accomplished by co-blending the nutrient phase with the fluoropolymer resin prior to extrusion and expansion of the fluoropolymer.

[0167] In some embodiments, the aquaculture substrate comprises an expanded thermoplastic polymer. In some embodiments, the expanded thermoplastic polymer forms the microstructure of the aquaculture substrate. In some embodiments, the expanded thermoplastic polymer is selected from the group of expanded polyester sulfone (ePES), expanded ultra-high molecular weight polyethylene (eUHMWPE), expanded polylactic acid (ePLA), and expanded polyethylene (ePE).

[0168] In some embodiments, the aquaculture substrate comprises an expanded polymer. In some embodiments, the expanded polymer forms the microstructure of the aquaculture substrate. In some embodiments, the expanded polymer is an expanded polyurethane (ePU).

[0169] In some embodiments, the expanding polymer includes a nutrient phase, which can be accomplished by co-blending the nutrient phase with the fluoropolymer resin prior to expanding the polymer.

[0170] In some embodiments, the aquaculture substrate comprises a polymer formed by expansion chemical vapor deposition (CVD). In some embodiments, the polymer formed by expansion CVD forms the microstructure of the aquaculture substrate. In some embodiments, the polymer formed by expansion CVD is polyparaxylylene (ePPX).

[0171] It will be recognized that certain of these materials may be better suited for use as one of the low porosity or high porosity substrates. In other embodiments, the low porosity and high porosity substrates are formed from the same type of material, but the materials may be processed in different ways to provide the various fibrillated submicron surface structures and microstructures described herein.

[0172] In some embodiments, the material forms or can be processed to form a fibrillated submicron surface structure. In some embodiments, the fibrillated submicron surface structure is produced by densifying and expanding an expanded fluoropolymer, expanded thermoplastic polymer, expanded polymer, or ePPX. Examples of densified fluoropolymer materials suitable for use as low porosity substrates are taught in U.S. Patent No. 7,521,010 to Kennedy, the contents of which are incorporated herein by reference in their entirety. Kennedy has a fibrillated submicron surface structure of about 0.015 g-mm / m 2 This paper teaches a densified fluoropolymer article having a water vapor transmission rate of 100 / day or less and a matrix tensile strength of at least 10,000 psi in two orthogonal directions. The article is made by compressing expanded porous PTFE at a pressure, temperature, and time that results in nearly complete elimination of porosity, followed by stretching at a temperature above the crystalline melt temperature. The stretching process results in a densified ePTFE sheet that has a greater tensile strength in the direction of stretch than the compressed precursor (which forms the densified ePTFE sheet).

[0173] As taught by Kennedy, ePTFE sheets or films were produced according to the teachings of US Patent No. 3,953,566. The ePTFE film is then compressed according to the teachings of US Patent No. 5,374,473. The densified film is then stretched at a temperature above the crystalline melting temperature of PTFE. The stretching ratio is, for example, 12:1 at a stretching rate of 5% per second. The stretching process can be carried out in either direction, both directions, sequentially or simultaneously on a tenter or similar machine, using a pantograph machine or continuously. The thickness of the compressed precursor directly affects the ability to achieve high stretch amounts, since the bulk density increases when the compressed precursor is stretched at a temperature above the crystalline melting temperature of ePTFE. Stretching results in a reduction in unit weight and thickness. A significant increase in the matrix tensile strength of one or more sheets is also observed. The densification and stretching procedures result in a film that is very thin, has high PTFE bulk density and low porosity, with an extraordinary water vapor transmission coefficient and high tensile strength in both the x- and y-directions. In some embodiments, the ePTFE film is sintered prior to the densification step. Additionally, biaxial ePTFE films can include two or more layers of ePTFE. This process can be performed continuously.

[0174] In some embodiments, similar processes can be applied to other expanded fluoropolymers, expanded thermoplastic polymers, expanded polymers, or ePPX to produce densified membranes with fibrillated submicron surface structures that can be used as low porosity substrates in the described aquaculture substrates.

[0175] In certain embodiments, the densified membrane is stretched at a temperature below the crystalline melting temperature of the expanded fluoropolymer film. In some embodiments, the densified membrane is stretched at a temperature just below the crystalline melting temperature. The interfibril distance and general morphology of the fibrillated submicron surface structure can be controlled by the stretching speed and stretching temperature. In some embodiments, the stretching speed and temperature are selected to produce a node and fibril nanostructure in which the fibrils are interconnected through the nodes. In other embodiments, the stretching speed and temperature are selected to minimize or eliminate the generation of nodes.

[0176] In certain embodiments, the fibrillated submicron surface structure occurs on only one side of the low porosity substrate, providing seaweed attachment only on the side having the submicron surface structure, in some embodiments, the side lacking the submicron surface structure is bonded, for example, to a backing layer.

[0177] The depth of the fibrillated submicron surface structure can be controlled by the densification and drawing steps.

[0178] In some embodiments, the expanded fluoropolymer forms the microstructure of the aquaculture substrate.

[0179] In some embodiments, the aquaculture system described herein can be used to cultivate seaweed. Seaweed spores are contacted under predetermined conditions and for a sufficient time with a culture substrate having desired properties to retain and keep the spores viable until at least a portion of the spores germinate and are retained (i.e., attached) by the culture substrate. In some embodiments, the culture substrate can be incubated in a medium that is conducive to spore germination and growth of the germinated spores. In other embodiments, the aquaculture system itself provides a microenvironment that is conducive to spore germination and growth of the germinated spores, at least for a period of time (e.g., during temporary transportation).

[0180] In some embodiments, the aquaculture substrate described herein can be used as a growth substrate for multicellular organisms from spores. For example, the aquaculture substrate can be used to support the growth of seaweed from spores to mature seaweed. In some embodiments, the spores that mature into multicellular organisms are contacted with the aquaculture substrate under defined conditions for a sufficient time until at least a portion of the spores germinate and are retained by the aquaculture substrate.

[0181] In some embodiments, seaweed spores are introduced onto the cultivation substrate and gametophytes and sporophytes are allowed to mature by depositing the cultivation substrate, with or without spores, onto a rope, cable or other support at the farm in a manner similar to traditional culture strings, obviating the traditional step of wrapping the cultivation string around a rope line. This can be accomplished when the cultivation substrate is provided by a plurality of particles in a dispersion.

[0182] In another embodiment, seaweed sporophytes and / or gametophytes are introduced directly into the aquaculture substrate. Such direct seeding can reduce the laboratory time required to generate aquaculture strings compared to spore seeding.

[0183] Culture strings are traditionally maintained and cultivated in a laboratory environment using sterile seawater. The aquaculture system of the present invention avoids the need for expensive and cumbersome systems required for circulating sterile seawater by providing a saltwater microenvironment within the microstructure of the highly porous substrate through the inclusion of sufficient salt within the microstructure. In some embodiments, the seeded aquaculture substrate is maintained in a standard seaweed culture tank where nutrients are delivered via the sterile seawater. By including sufficient nutrient phase to support seaweed growth, the need to provide external nutrients to the growing seaweed can be eliminated.

[0184] Typically, the culture strings must be transported carefully in seawater, avoiding collisions to prevent detachment of gametophytes and sporophytes from the strings. The culture system described here allows gametophytes and sporophytes to be safely transported without seawater. This can be achieved by including a salt and liquid-containing phase within the microstructure, which provides a saline microenvironment with sufficient moisture to support juvenile seaweed during transport.

[0185] In some embodiments, it is possible to reuse a cultivation substrate, such as a low porosity substrate, or a portion thereof, by controlling the strength of attachment of the seaweed to the fibrillated sub-micron surface structure. The fibrillated sub-micron surface structure can be controlled to provide a strong enough bond to allow cultivation, but not so strong that the fastener cannot be mechanically removed, such as by vigorous washing. The low porosity substrate can be reused after removal of the attached seaweed.

[0186] The invention of this application has been described generally and with reference to specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments without departing from the scope of the present disclosure. Therefore, the embodiments are intended to cover the modifications and variations of the present invention as long as they come within the scope of the appended claims and their equivalents. (Aspect) (Aspect 1) An aquaculture system comprising: a low-porosity substrate having a porosity of about 10% or less; and an aquaculture substrate comprising a fibrillated sub-micron surface structure configured to hold seaweed by an anchoring device. (Aspect 2) 2. The aquaculture system of claim 1, wherein the fibrillated submicron surface structure is characterized by an average interfibril distance of 1000 nm or less. (Aspect 3) 3. The aquaculture system of claim 1 or claim 2, wherein the fibrillated submicron surface structures have an average depth of about 1000 nm or less. (Aspect 4) 4. The aquaculture system of any one of claims 1 to 3, wherein the fibrillated submicron surface structures have an average depth of about 5 nm or less. (Aspect 5) 5. The aquaculture system of any one of claims 1-4, wherein the low porosity substrate is from about 25.4 μm (1 mil) to about 762 μm (30 mils) thick. (Aspect 6) 6. The aquaculture system of any one of claims 1-5, wherein the low porosity substrate is from about 25.4 μm (1 mil) to about 127 μm (5 mils) thick. (Aspect 7) 7. The aquaculture system of any one of the preceding claims, wherein the aquaculture substrate is configured as a tape, a substrate, a woven article, a nonwoven article, a braided article, a knitted article, a fabric, a particle dispersion, or a combination of two or more of the foregoing. (Aspect 8) 8. The aquaculture system of any one of the preceding claims, wherein the aquaculture substrate comprises at least one of a backer layer, a carrier layer, a laminate of multiple layers, a composite material, or a combination thereof. (Aspect 9) 9. The aquaculture system of any one of the preceding claims, wherein the low porosity substrate comprises an expanded fluoropolymer. (Aspect 10) 10. The aquaculture system of embodiment 9, wherein the expanded fluoropolymer is one of expanded fluorinated ethylene propylene (eFEP), porous perfluoroalkoxyalkane (PFA), expanded ethylene tetrafluoroethylene (eETFE), expanded vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene polymer (eVDF-co-(TFE or TrFE)), and expanded polytetrafluoroethylene (ePTFE). (Aspect 11) 11. The aquaculture system according to any one of the preceding claims, wherein the low porosity substrate is an expanded polytetrafluoroethylene (ePTFE) substrate. (Aspect 12) 9. The aquaculture system of any one of the preceding claims, wherein the low porosity substrate comprises an expanded thermoplastic polymer. (Aspect 13) 13. The aquaculture system of claim 12, wherein the expanded thermoplastic polymer is one of expanded polyestersulfone (ePES), expanded ultra-high molecular weight polyethylene (eUHMWPE), expanded polylactic acid (ePLA), and expanded polyethylene (ePE). (Aspect 14) 9. The aquaculture system of any one of the preceding claims, wherein the low porosity substrate comprises an expanded polymer. (Aspect 15) 15. The aquaculture system of embodiment 14, wherein the expanded polymer is expanded polyurethane (ePU). (Aspect 16) 9. The aquaculture system according to any one of the preceding claims, wherein the low porosity substrate is expanded polyparaxylylene (ePPX). (Aspect 17) The PTFE base material is approximately 0.015 g-mm / m 2 12. The aquaculture system of embodiment 11, wherein the aquaculture system has a water vapor transmission coefficient of 1000 sq. m / day or less and is formed by a process comprising: (a) preparing a biaxially stretched PTFE film; (b) densifying the expanded PTFE film; and (c) stretching the densified expanded PTFE film. (Aspect 18) 20. The aquaculture system of claim 17, wherein in step (c), the densified expanded PTFE film is stretched at a temperature above the crystalline melting temperature of PTFE. (Aspect 19)

[0023] 19. The aquaculture system of claim 17 or 18, wherein the expanded PTFE film is sintered prior to step (b). (Aspect 20) 20. The aquaculture system of any one of embodiments 17-19, wherein the biaxially expanded PTFE film comprises two or more layers of expanded PTFE. (Aspect 21) 21. The aquaculture system according to any one of embodiments 17 to 20, wherein steps (a) to (c) are carried out in a continuous manner. (Aspect 22) 22. The aquaculture system of any one of the preceding claims, wherein the aquaculture substrate further comprises a highly porous substrate having a node and fibril microstructure characterized by a porosity of at least 30%, an average interfibril distance of about 1 μm to 500 μm, or an average pore size of about 1 μm to about 500 μm. (Aspect 23) 23. The aquaculture system of claim 22, wherein the highly porous substrate comprises an expanded fluoropolymer. (Aspect 24) 24. The aquaculture system of claim 22 or 23, wherein the expanded fluoropolymer is one of expanded fluorinated ethylene propylene (eFEP), porous perfluoroalkoxyalkane (PFA), expanded ethylene tetrafluoroethylene (eETFE), expanded vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene polymer (eVDF-co-(TFE or TrFE)), and expanded polytetrafluoroethylene (ePTFE). (Aspect 25) 25. The aquaculture system of any one of claims 22 to 24, wherein the highly porous substrate is an expanded polytetrafluoroethylene (ePTFE) substrate. (Aspect 26) 23. The aquaculture system of claim 22, wherein the highly porous substrate comprises an expanded thermoplastic polymer. (Aspect 27) 27. The aquaculture system of claim 26, wherein the expanded thermoplastic polymer is one of expanded polyestersulfone (ePES), expanded ultra-high molecular weight polyethylene (eUHMWPE), expanded polylactic acid (ePLA), and expanded polyethylene (ePE). (Aspect 28) 23. The aquaculture system of claim 22, wherein the highly porous substrate comprises an expanded polymer. (Aspect 29) 30. The aquaculture system of embodiment 28, wherein the expanded polymer is expanded polyurethane (ePU). (Aspect 30) 23. The aquaculture system of claim 22, wherein the highly porous substrate is expanded polyparaxylylene (ePPX). (Aspect 31) 31. The aquaculture system of any one of claims 22 to 30, wherein the highly porous substrate is hydrophobic. (Aspect 32) 32. The aquaculture system of any one of claims 22-31, wherein the low porosity substrate and the high porosity substrate comprise the same material. (Aspect 33) 33. The aquaculture system of any one of aspects 22 to 32, wherein the aquaculture substrate is a patterned substrate having a pattern of low porosity substrate and high porosity substrate. (Aspect 34) 34. The aquaculture system of claim 33, wherein the pattern of low porosity substrates and high porosity substrates is an organized or selective pattern. (Aspect 35) 34. The aquaculture system of embodiment 33, wherein the pattern of the low porosity substrate and the high porosity substrate is a random pattern. (Aspect 36) 36. The aquaculture system according to any one of the preceding aspects, further comprising a nutrient phase associated with at least a part of said aquaculture substrate. (Aspect 37) 37. The aquaculture system of embodiment 36, wherein the nutrient phase promotes seaweed growth and / or attachment of seaweed to the aquaculture substrate. (Aspect 38) 38. The aquaculture system of aspect 36 or 37, wherein at least a portion of the nutrient phase is entrained within, entrained on, or entrained within and on the aquaculture substrate. (Aspect 39) 39. The aquaculture system according to any one of embodiments 36 to 38, wherein the nutrient phase is present as a coating on a surface of the aquaculture substrate. (Aspect 40)

[0041] Aspect 40. The aquaculture system of any one of aspects 1-39, wherein the aquaculture substrate is provided by a plurality of particles in a dispersion formulated for deposition onto a backer layer or carrier substrate. (Aspect 41) 41. The aquaculture system of any one of the preceding aspects, wherein the cultivation substrate is asymmetric and comprises fibrillated sub-micron surface structures configured to retain seaweed on only one side. (Aspect 42) 42. A method of cultivating seaweed comprising contacting a population of seaweed gametophytes and / or sporophytes with a cultivation substrate of the cultivation system according to any one of aspects 1 to 41 until at least a portion of the population of seaweed gametophytes and / or sporophytes form an anchorage to the nanostructures of said cultivation substrate. (Aspect 43) 26. The method of embodiment 25, further comprising placing the aquaculture system in an open water environment after a portion of the population of seaweed gametophytes and / or sporophytes have formed anchorages to the nanostructures of the aquaculture substrate.

Claims

1. an aquaculture substrate comprising a low porosity substrate having a porosity of 10% or less; a nutrient phase associated with at least a portion of the culture substrate; An aquaculture system comprising: the low porosity substrate having a fibrillated submicron surface structure; and The fibrillated sub-micron surface structure is configured to hold seaweed with an anchoring device.

2. 2. The aquaculture system of claim 1, wherein the fibrillated submicron surface structure is characterized by an average interfibril distance of 1000 nm or less.

3. 3. The aquaculture system of claim 1 or claim 2, wherein the fibrillated submicron surface structures have an average depth of 1000 nm or less.

4. 4. The aquaculture system of claim 1, wherein the low porosity substrate is between 1 mil and 30 mils thick.

5. 5. The aquaculture system of claim 1, wherein the aquaculture substrate is configured as a tape, a substrate, a woven article, a nonwoven article, a braided article, a knitted article, a fabric, a particle dispersion, or a combination of two or more of the foregoing.

6. The aquaculture system of any one of claims 1 to 5, wherein the aquaculture substrate comprises at least one of a backer layer, a carrier layer, a laminate of multiple layers, a composite material, or a combination thereof.

7. The aquaculture system of any one of claims 1 to 6, wherein the low porosity substrate comprises an expanded fluoropolymer.

8. 8. The aquaculture system of claim 7, wherein the expanded fluoropolymer is one of expanded fluorinated ethylene propylene (eFEP), porous perfluoroalkoxyalkane (PFA), expanded ethylene tetrafluoroethylene (eETFE), expanded vinylidene fluoride-co-tetrafluoroethylene or trifluoroethylene polymer (eVDF-co-(TFE or TrFE)), and expanded polytetrafluoroethylene (ePTFE).

9. 2. The aquaculture system of claim 1, wherein the low porosity substrate is an expanded polytetrafluoroethylene (ePTFE) substrate.

10. 7. The aquaculture system of claim 1, wherein the low porosity substrate comprises an expanded thermoplastic polymer. Claim 11: The ePTFE base material is 0.015g-mm / m ２ 10. The method of claim 9, wherein the aquaculture system has a water vapor transmission coefficient of 0.1 MPa or less per 1000 sq. m / day and is formed by a process comprising: (a) preparing a biaxially stretched PTFE film; (b) densifying the expanded PTFE film; and (c) stretching the densified expanded PTFE film.

12. 12. The method of claim 11, wherein in step (c), the densified expanded PTFE film is expanded at a temperature above the crystalline melting temperature of PTFE.

13. The method of claim 11 or 12, wherein the expanded PTFE film is sintered prior to step (b).

14. The method for producing an aquaculture system according to any one of claims 11 to 13, wherein steps (a) to (c) are carried out in a continuous manner.

15. 10. The aquaculture system of claim 1, wherein the nutrient phase promotes seaweed growth and / or attachment of seaweed to the culture substrate.

16. 20. The aquaculture system of claim 1 or 15, wherein at least a portion of the nutrient phase is entrained within the culture substrate, entrained on the culture substrate, or entrained within and on the culture substrate.

17. 17. The aquaculture system of claim 1, 15 or 16, wherein the nutrient phase is present as a coating on a surface of the aquaculture substrate.

18. A method for cultivating seaweed comprising contacting a population of seaweed gametophytes and / or sporophytes with a cultivation substrate of the cultivation system according to any one of claims 1 to 10 until at least a portion of the population of seaweed gametophytes and / or sporophytes forms an anchorage to the nanostructures of said cultivation substrate.

19. 20. The method of claim 18, further comprising placing the aquaculture system in an open water environment after a portion of the population of seaweed gametophytes and / or sporophytes have formed anchorages to the nanostructures of the aquaculture substrate.

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