Fish and shellfish symbiotic offshore net cage culture system and culture method

Abstract

The invention discloses a fish and shellfish symbiosis seaborne net cage culture system and method, and relates to the technical field of aquaculture, and the method comprises the following steps: arranging a culture net cage in an offshore sea area; fish fries are put into a surrounding net, bivalve shellfishes are put into a shellfish culture piece cage, and the shellfish culture piece cage is hung in the culture net cage; feeding bait irregularly, checking the integrity of the shellfish culture cage and the covering condition of attachments regularly, and making a treatment means according to the covering rate; in the later period of culture, the adult fishes with the body length exceeding a preset value are caught irregularly in a fishing mode, and after the culture period is finished, the remaining adult fishes are caught in a concentrated mode by increasing the height of the purse seine; the shellfish culture piece cage is lifted out of the water surface to collect adult shellfish. The culture system disclosed by the invention comprises a culture net cage and shellfish culture piece cages, wherein the shellfish culture piece cages are hung in a purse seine. According to the method, mutualism of marine fishes and bivalve shellfish can be achieved, the resource utilization rate and the culture benefits are improved, and diversified fishery development can be achieved.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and in particular to a fish and shellfish symbiotic marine cage culture system and culture method. Background Technology

[0002] Marine fish, as an important category of aquaculture, are mostly omnivorous or carnivorous, and their feeding characteristics have not been fully utilized under traditional farming methods. At the same time, large-scale cage aquaculture in nearshore waters faces severe ecological challenges. Due to high stocking densities, large amounts of uneaten feed settling, and the continuous accumulation of fish excrement, large amounts of nutrients such as nitrogen and phosphorus are constantly being introduced into the aquaculture water, far exceeding the self-purification capacity of nearshore waters, directly leading to increasingly prominent eutrophication problems. Eutrophic water environments provide a breeding ground for the explosive proliferation of algae (such as diatoms and dinoflagellates), which not only consumes large amounts of dissolved oxygen in the water, causing oxygen stress in farmed fish, but may also trigger ecological disasters such as red tides, causing chain reactions of damage to plankton and benthic organisms in nearshore waters, seriously threatening the balance and stability of the entire nearshore ecosystem.

[0003] Bivalve aquaculture, such as that of oysters and scallops, typically employs raft or bottom-seeding methods. While bivalve shells can filter-feed on plankton and organic debris, the farming efficiency and space utilization need improvement. Furthermore, in traditional single-species offshore bivalve hanging culture, barnacles, algae, sponges, and other marine fouling organisms easily adhere to the shell surface. As these deposits accumulate, the shells' ability to open and close is restricted, potentially leading to death due to the inability to filter feed and breathe properly. To ensure healthy growth, regular cleaning of the shell surface is necessary, a process that is both labor-intensive and time-consuming, significantly hindering the large-scale and efficient development of the bivalve aquaculture industry.

[0004] Currently, some fish-shellfish polyculture techniques employ a nested enclosure method, setting up two inner and outer nested nets, with fish farming in the center and shellfish farming in between. While this method allows shellfish to filter food and waste, the presence of the intervening nets prevents fish from utilizing the shellfish's surface, resulting in some resource waste. Furthermore, in this polyculture method, the fish are located further inside the enclosure, and harvesting is limited to the final hauling of the nets, making it a simplistic approach that hinders the development of diverse fisheries.

[0005] Therefore, there is an urgent need for a fish-shellfish symbiotic marine cage culture system and method to solve the aforementioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a fish-shellfish symbiotic marine cage aquaculture system and method to solve the problems existing in the prior art, realize the mutually beneficial symbiosis of marine fish and bivalve shellfish, improve resource utilization and aquaculture efficiency, and achieve diversified fishery development.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides a breeding method, comprising the following steps: Step 1: Deploy aquaculture cages in nearshore waters, and ensure that the upper part of the enclosure net is above the water surface; Step 2: Place the fish fry into the enclosure net, place the bivalve shellfish into the shellfish culture cage, and suspend the shellfish culture cage inside the culture net box; Step 3: Feed small amounts of supplementary food to the fish periodically. Regularly check the integrity of the mesh of the shellfish farming cage and the coverage of shell attachments. When the shell attachment coverage is less than 30%, rely on the fish to peck at and clean it naturally. If the coverage exceeds 30%, the shellfish farming cage should be lifted out of the water and the shell surface cleaned. After cleaning, it should be hoisted back into place to prevent attachments from affecting the growth of shellfish. The mesh of the shellfish farming cage should be replaced regularly to prevent the mesh from becoming clogged or damaged, which could cause the shellfish larvae to escape. Step 4: In the later stages of aquaculture, fish are caught intermittently by fishing, prioritizing the harvesting of adult fish that exceed the preset length, while keeping individuals smaller than the preset size to continue growing. When the aquaculture cycle ends, the height of the enclosure net is raised to create a closed harvesting space, and then a trawl net is used to drag along the bottom of the aquaculture cages to harvest the remaining adult fish. Subsequently, the shellfish farming cages are lifted out of the water one by one, the mesh nets are disassembled to collect the shellfish, and they are sorted and packed into boxes.

[0008] In some implementations, the sheet netting of the shellfish farming cages is replaced every two months, and the integrity of the sheet netting and the coverage of shell attachments are checked weekly.

[0009] In some implementations, the preset value for body length is 25cm.

[0010] This invention also provides a fish and shellfish symbiotic marine cage culture system, including a culture cage and shellfish culture trays. The culture cage includes a fixed base and a perimeter net. The perimeter net is fixedly installed below the fixed base to form a fish culture space. The shellfish culture tray includes a sheet-like frame and a sheet-like net. The sheet-like net covers the surface of the sheet-like frame, and the sheet-like nets at both ends of the sheet-like frame are connected to form a shellfish culture space. The shellfish culture space can be divided into multiple spaces, and the shellfish culture trays are suspended inside the perimeter net. It also includes a hanging rope and a triangular ring, the triangular ring being fixedly installed at both ends of the sheet frame, and the two ends of the hanging rope being able to be tied to the sheet frame or to the triangular ring.

[0011] In some embodiments, the system also includes a main aquaculture raft, which is fixedly installed on the nearshore sea surface, and multiple aquaculture cages are fixedly installed inside the main aquaculture raft.

[0012] In some embodiments, a connecting pedal is also included, which is fixedly disposed between the frame of the main aquaculture raft and the fixed base.

[0013] In some embodiments, the frame of the main aquaculture raft and the fixed base are both formed by splicing plastic pipes, and semi-circular grooves are provided on both sides of the connecting pedal, which can be engaged with the outer circumferential surface of the plastic pipes.

[0014] In some embodiments, a hanging frame is also included. Both the hanging frame and the fixed base are square and are concentrically arranged. The four corners of the hanging frame are connected to the four corners of the aquaculture net cage by pull ropes. The shellfish aquaculture cages are suspended on both the hanging frame and the fixed base.

[0015] In some embodiments, the fixed base includes a first rectangular fence, a second rectangular fence, and support posts. The second rectangular fence is located above the first rectangular fence, and the first rectangular fence and the second rectangular fence have the same specifications and are concentrically arranged. Multiple support posts are provided, and the two ends of the support posts are fixedly connected to the first rectangular fence and the second rectangular fence, respectively.

[0016] In some embodiments, the connecting pedal is provided with multiple water-permeable holes and anti-slip texture.

[0017] The present invention achieves the following technical effects compared to the prior art: The fish-shellfish symbiotic marine cage culture method provided by this invention utilizes the omnivorous nature of fish. Fish can feed on the attached matter on the shells of bivalves. The bivalves, suspended in the cages within the netting, can efficiently ingest organic detritus, plankton, and nutrients such as nitrogen and phosphorus produced by fish metabolism through filter feeding. This transforms pollutants from fish farming into nutrients for their own growth, effectively utilizing nutrients in the aquaculture water and reducing pollution from uneaten feed and feces, thus achieving ecological and environmentally friendly aquaculture. Furthermore, by using this fish-shellfish symbiotic marine cage culture method, mixed cultivation of fish and shellfish fully utilizes biological habits, improves the utilization rate of unit space, and reduces the environmental impact of large-scale cage culture. Moreover, the fish farming space is located further out than the shellfish farming space, facilitating the establishment of a fishing industry. This allows for fishing beyond final net hauling, enriching the fisheries industry and generating some cost recovery through fishing.

[0018] This fish-shellfish symbiotic marine cage culture method organically combines ecological symbiosis, three-dimensional aquaculture, green pest control, graded harvesting, and recreational fishing. While increasing output per unit area of ​​sea area and reducing aquaculture costs and environmental impact, it also optimizes harvesting patterns and expands profit channels. It solves the problems of wasted space, high environmental pressure, and limited profit models associated with traditional marine aquaculture, and achieves a synergistic improvement in ecological, economic, and social benefits, making it suitable for large-scale, sustainable application in nearshore waters. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a fish and shellfish symbiotic marine cage aquaculture system in some embodiments of the present invention; Figure 2 This is a schematic diagram of the connecting pedal structure in some embodiments of the present invention; Figure 3 This is a schematic diagram of the structure of the aquaculture cage in some embodiments of the present invention; Figure 4 This is a schematic diagram showing the connection between the aquaculture net cage and the shellfish aquaculture cage in some embodiments of the present invention; Figure 5 This is a schematic diagram showing the connection between the aquaculture net cage, the shellfish aquaculture tray, and the hanging frame in some embodiments of the present invention; Figure 6This is a schematic diagram of the structure of shellfish farming cages in some embodiments of the present invention.

[0021] In the diagram: 1-Main aquaculture raft; 2-Connecting footboard; 21-Water permeable hole; 22-Semi-circular groove; 3-Aquaculture net cage; 31-Fixing base; 311-First rectangular fence; 312-Second rectangular fence; 313-Supporting column; 32-Enclosure net; 4-Hanging frame; 5-Pull rope; 6-Shellfish aquaculture cage; 61-Sheet net; 62-Sheet frame; 63-Triangular ring; 7-Hanging rope. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The purpose of this invention is to provide a fish-shellfish symbiotic marine cage aquaculture system and method to solve the problems existing in the prior art, realize the mutually beneficial symbiosis of marine fish and bivalve shellfish, improve resource utilization and aquaculture efficiency, and reduce labor input and environmental pollution.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1 This embodiment provides a breeding method, including the following steps. Step 1: Set up aquaculture cages 3 in nearshore waters, with the upper part of the enclosure net 32 ​​above the water surface to prevent fish from escaping.

[0026] Step Two: Place the fish fry into the fish rearing space within the enclosure 32, and the bivalve mollusks into the mollusks rearing space within the mollusks rearing cage 6. The mollusks rearing cage 6 is then suspended within the rearing net cage 3. Care should be taken to avoid damaging the fish and mollusks during stocking, and the stocking density should be controlled to ensure sufficient living space and growth environment. Suitable fish species include black sea bream and blue bream, while suitable bivalve mollusks include pearl oysters, mussels, and oysters.

[0027] Step 3: Feed small amounts of supplementary food to the fish periodically. Regularly check the integrity of the mesh 61 of the shellfish farming cage 6 and the coverage of shell attachments. When the shell attachment coverage is less than 30%, rely on the fish to naturally peck and clean it. If the coverage exceeds 30%, the shellfish farming cage 6 should be lifted out of the water as a whole and the shell surface cleaned. It is preferable to use a high-pressure water gun and scraper to clean it. After cleaning, it should be lifted back into place to avoid the attachments affecting the growth of the shellfish. Replace the mesh 61 of the shellfish farming cage 6 every once in a while to prevent the mesh from becoming clogged or damaged, which could cause the shellfish seedlings to escape. Shellfish can filter organic debris, plankton, and some suspended matter produced by fish metabolism in the water, realizing material circulation within the farming system, reducing external pollutants, reducing the risk of water quality deterioration, and forming a benign fish-shellfish symbiotic micro-ecology.

[0028] Step Four: In the later stages of aquaculture, fish are harvested intermittently using angling, prioritizing the harvesting of adult fish exceeding the set length, while allowing smaller individuals to continue growing. At the end of the aquaculture cycle, the height of the enclosure net 32 ​​is raised to create a closed harvesting space, and a trawl net is used to drag the remaining adult fish along the bottom of the aquaculture cage 3. Subsequently, the shellfish farming cages 6 are lifted out of the water one by one, the mesh nets 61 are dismantled to collect the adult shellfish, and they are then sorted and packaged. This graded harvesting not only ensures full utilization of aquaculture resources and avoids the waste of yield caused by premature harvesting of smaller fish, but also allows for staggered market entry, mitigating the risk of price fluctuations from concentrated market entry. Furthermore, graded harvesting reduces the shock and damage to the fish population caused by single harvesting, improving the survival rate and market quality of adult fish.

[0029] The use of this fish-shellfish symbiotic marine cage culture method allows for the mixed cultivation of fish and shellfish in marine aquaculture, fully utilizing their biological habits, improving the utilization rate of unit space, and reducing the environmental impact of large-scale cage culture. Furthermore, the fish farming space is located further out than the shellfish farming space, facilitating the establishment of a fishing industry. This allows fish harvesting to extend beyond net fishing to include angling, enriching the fisheries sector and enabling some cost recovery.

[0030] This fish-shellfish symbiotic marine cage culture method organically combines ecological symbiosis, three-dimensional aquaculture, green pest control, graded harvesting, and recreational fishing. While increasing output per unit area of ​​sea area and reducing aquaculture costs and environmental impact, it also optimizes harvesting patterns and expands profit channels. It solves the problems of wasted space, high environmental pressure, and limited profit models associated with traditional marine aquaculture, and achieves a synergistic improvement in ecological, economic, and social benefits, making it suitable for large-scale, sustainable application in nearshore waters.

[0031] In some embodiments, the sheet netting of shellfish farming cages is replaced every two months, and the integrity of the sheet netting and the coverage of shell attachments are checked weekly. Routine weekly checks of the sheet netting integrity allow for the timely detection of problems such as netting damage, tears, and mesh deformation, enabling early warning and intervention before shellfish escape or the scale of farming is damaged. Combined with the regular replacement every two months, this fundamentally prevents irreversible damage caused by prolonged immersion in seawater, aging and brittleness of the netting, and nibbling by marine organisms. This dual control system forms a closed loop, minimizing the risk of escape for larvae and adult shellfish, ensuring a stable farming population, and reducing direct economic losses caused by escape.

[0032] In some embodiments, the preset body length of the fish is 25cm. At this size, the fish have completed their main growth stage, their growth rate has slowed, and their feed conversion rate has decreased. Continuing to raise them would result in high feed input and low weight gain. Using this standard for grading and harvesting allows for the precise selection of adult fish with declining growth potential, while preserving smaller individuals still in their rapid growth phase. This prioritizes aquaculture resources such as feed, water, and manpower for fish that still have room to grow, thereby improving the overall input-output ratio of aquaculture.

[0033] Example 2 like Figures 1-6 As shown, the present invention provides a fish and shellfish symbiotic marine cage aquaculture system, including: an aquaculture cage 3 and a shellfish aquaculture cage 6. The aquaculture cage 3 includes a fixed base 31 and a perimeter net 32. The perimeter net 32 ​​is fixedly installed below the fixed base 31 to form a fish aquaculture space. The shellfish aquaculture cage 6 includes a sheet-like frame 62 and a sheet-like net 61. The sheet-like net 61 covers the surface of the sheet-like frame 62, and the sheet-like nets 61 at the two side ends of the sheet-like frame 62 are connected to form a shellfish aquaculture space. The shellfish aquaculture space can be divided into multiple spaces. The shellfish aquaculture cage 6 is suspended inside the perimeter net 32.

[0034] Taking advantage of their omnivorous nature, fish can feed on the attachments to bivalve shells, such as algae and barnacles, thus reducing the need for manual cleaning and lowering management costs. The suspended shellfish farming cages 6 can act as artificial reefs, providing fish with more habitats and hiding places, creating a more suitable environment for their growth and reproduction. Furthermore, in this mutually beneficial aquaculture model, uneaten feed and excrement generated during fish farming directly enter the seawater environment within the enclosure net 32. The bivalve shellfish (such as oysters and scallops) suspended in the cages 6 can efficiently absorb these organic debris, plankton, and nutrients such as nitrogen and phosphorus produced by fish metabolism through filter feeding, converting pollutants from fish farming into nutrients for their own growth. This effectively utilizes nutrients in the aquaculture water, reduces pollution from uneaten feed and excrement, lowers the risk of red tide outbreaks, and achieves eco-friendly aquaculture. Moreover, by fully utilizing the aquaculture space within the cages, polyculture of fish and shellfish is achieved, increasing the yield per unit area and thus obtaining greater economic benefits. Furthermore, the space of the shellfish farming cage 6 can be divided into multiple independent units. The intensive design not only facilitates the separate management of different shellfish species and different growth stages, but also avoids growth differences caused by excessive density during the farming process. At the same time, it ensures that each shellfish farming unit can evenly obtain nutrients from the water, thereby improving the overall efficiency of shellfish farming.

[0035] It should be noted that the size of the enclosure net (32mm) is determined according to actual production needs, and the mesh size depends on the species of fish being farmed. Suitable fish and shellfish species should be selected for farming based on the environmental conditions of the aquaculture area and market demand. Fish should be omnivorous, fast-growing, and disease-resistant, while bivalve shellfish should be fast-growing, adaptable, and have high economic value.

[0036] In some embodiments, the fish-shellfish symbiotic marine cage aquaculture system also includes a main aquaculture raft 1, which is fixedly set on the nearshore sea surface, and multiple aquaculture cages 3 are fixedly set inside the main aquaculture raft 1. The multiple aquaculture cages 3 fixedly set inside the main aquaculture raft 1 integrate scattered fish-shellfish symbiotic aquaculture units into a large-scale aquaculture cluster. Farmers can complete feeding, pond inspection, harvesting, and shellfish cage maintenance for all cages on the same aquaculture raft, eliminating the need for frequent transfers between multiple independent cages, significantly reducing travel time and labor input at sea, and improving the efficiency of aquaculture management. Each aquaculture cage 3 is a standardized fish-shellfish symbiotic unit. Relying on the unified framework of the main aquaculture raft 1, standardized settings can be achieved for parameters such as culture density, shellfish cage suspension method, and cage layout. Independent cages are easily displaced and capsized by wind and waves in the nearshore environment, while the main aquaculture raft 1, as a unified load-bearing framework, has an overall structural strength far exceeding that of a single cage, effectively dispersing the forces of wind and waves and improving the entire aquaculture system's resistance to wind, waves, and ocean currents. Meanwhile, multiple cages are fixed inside the aquaculture raft, forming a synergistic stabilizing effect among themselves, further reducing the risk of cage overturning or damage, and ensuring the continuity of aquaculture production.

[0037] In some embodiments, the fish and shellfish symbiotic marine cage aquaculture system also includes a connecting step 2, which is fixedly installed between the frame of the main aquaculture raft 1 and the fixed base 31, providing a walking path for aquaculture personnel. The barrier-free walking path formed by the connecting step 2 allows aquaculture personnel to walk directly from the main aquaculture raft 1 to the fixed base 31 of any aquaculture cage 3 without frequently getting on and off the raft or pulling ropes, completely changing the traditional decentralized cage aquaculture operation mode. In scenarios where multiple cages are configured on a large-scale aquaculture raft, the travel time for daily inspections, feeding, and disease screening can be significantly reduced, improving overall management efficiency. Based on the rapid passage capability of the connecting step 2, aquaculture personnel can complete the coordinated operation of multiple cages in a short time. For example, simultaneously checking the damage to the enclosure nets 32 of each cage, uniformly adjusting the hanging height of the shellfish aquaculture cages 6, and batch releasing fish fry or shellfish seedlings, avoiding time delays and repetitive work in traditional operation modes, further optimizing the management process of large-scale aquaculture.

[0038] In some embodiments, the frame and fixed base 31 of the main aquaculture raft 1 are both formed by splicing plastic pipes. Semi-circular grooves 22 are provided on both sides of the connecting pedal 2, and these grooves can engage with the outer circumferential surface of the plastic pipes. The arc of the semi-circular grooves 22 on both sides of the connecting pedal 2 perfectly matches the outer circumferential surface of the plastic pipes, forming surface contact rather than point or line contact during engagement. This ensures precise positioning and tight fit between the pedal and the plastic pipes of the frame of the main aquaculture raft 1 and the fixed base 31 of the net cage, effectively preventing the pedal from sliding horizontally or tilting vertically under the impact of walking or waves, thus ensuring the structural stability of the walking passage. The plastic pipes themselves have a certain degree of flexibility, while the engagement structure of the semi-circular grooves 22 provides a rigid connection. When encountering waves, slight deformation of the plastic pipes can be buffered by the engagement gap of the grooves, avoiding structural breakage caused by the rigid connection. At the same time, the rigid constraint of the engagement structure can limit excessive deformation of the pipes, ensuring that the connection between the pedal and the frame remains intact.

[0039] In some embodiments, the fish-shellfish symbiotic marine cage aquaculture system further includes a hanging frame 4. Both the hanging frame 4 and the fixed base 31 are square and concentrically arranged. The four corners of the hanging frame 4 are connected to the four corners of the aquaculture cage 3 via ropes 5. The square hanging frame 4 provides additional standardized suspension points for the shellfish aquaculture cages 6. Aquaculture personnel can suspend the shellfish cages between the hanging frame 4 and the fixed base 31, or below the hanging frame 4, to achieve layered expansion of the shellfish aquaculture space. Simultaneously, the concentric design of the square structure and the fixed base 31 makes the suspension position of the cages more regular, facilitating control of the spacing between cages and preventing mutual obstruction and entanglement caused by excessive density.

[0040] In some embodiments, the fixed base 31 includes a first rectangular fence 311, a second rectangular fence 312, and support columns 313. The second rectangular fence 312 is located above the first rectangular fence 311, and the first rectangular fence 311 and the second rectangular fence 312 are of the same specifications and concentrically arranged. Multiple support columns 313 are provided, and the two ends of the support columns 313 are fixedly connected to the first rectangular fence 311 and the second rectangular fence 312, respectively. Compared with a single-layer fence structure, the double-layer rigid frame with symmetrical upper and lower sections has significantly improved bending and torsional stiffness. When subjected to the impact of wind and waves, the walking load transmitted by the connecting footboard 2, and the self-weight of the net cage and the aquaculture inside, the double-layer fence can evenly distribute the force, avoiding frame deformation or breakage caused by local stress concentration. Multiple support columns 313 are vertically connected to the double-layer fence, upgrading the fixed base 31 from a planar frame to a three-dimensional truss structure. The support column 313 not only transmits the force between the upper and lower fences, but also effectively limits the relative displacement between the two layers of fences, enhancing the overall stability of the structure. At the same time, the three-dimensional truss structure has a better wind resistance coefficient, which can reduce the impact force of seawater flow on the fixed base 31, further improving the wind and wave resistance and ocean current resistance of the entire aquaculture cage 3. The double-layer rectangular fence provides a layered installation carrier for each component of the system: the lower first rectangular fence 311 can serve as the main fixed end of the enclosure net 32, ensuring the sealing and firmness of the connection between the enclosure net 32 ​​and the fixed base 31; the upper second rectangular fence 312 can be used to install the connection point of the pull rope 5 of the hanging frame 4, the auxiliary suspension point of the shellfish aquaculture cage 6, or to lay out feeding pipes, water quality monitoring sensors and other equipment. The layered design avoids installation conflicts between components on a single-layer fence and improves the space utilization of the fixed base 31.

[0041] It should be noted that the frame of the main aquaculture raft 1 is 13 meters. The square structure is made of plastic pipes with a diameter of 30cm. The first rectangular fence 311 and the second rectangular fence 312 are both 5 meters long. The enclosure is constructed using pipes with a diameter of 30 cm. Support columns 313 are rigid pipes, 50 cm long and 30 cm in diameter, placed at the four corners of the rectangular enclosure, two at each corner, for a total of eight support columns 313. The main aquaculture raft 1 has four areas in the middle for placing aquaculture net cages 3. Connecting steps 2 are placed between the main aquaculture raft 1 and the aquaculture net cages 3 for personnel to walk between the net cages. The number of connecting steps between the main aquaculture raft 1 and the aquaculture net cages 3 needs to be determined based on actual usage. The length, width, and height of the connecting steps 2 are... The side of the cage has a semi-circular groove 22 with a diameter of 30 cm. The hanging frame 4 is also composed of pipes with a diameter of 30 cm and is a square frame with an outer diameter of 2 meters. The distance between the hanging frame 4 and the fixed base 31 is 3 meters to facilitate activities such as fishing. The shellfish farming cages 6 are spaced 0.3 meters apart to maximize farming output while providing hiding space for fish.

[0042] In some embodiments, shellfish culture cages 6 are suspended on both the hanging frame 4 and the fixed base 31, which can make full use of the space inside the culture cage 3.

[0043] In some embodiments, the fish and shellfish symbiotic marine cage culture system further includes a hanging rope 7 and a triangular ring 63. The triangular ring 63 is fixedly installed at both ends of the sheet frame 62. The two ends of the hanging rope 7 can be tied to the sheet frame 62 or inside the triangular ring 63. When there are no waves or the waves are small, the two ends of the hanging rope 7 are tied to the top crossbar of the sheet frame 62, and the middle is suspended from the hanging frame 4 or the fixed base 31. At this time, the two ends of the hanging rope 7 can slide on the top crossbar of the sheet frame 62, and the top crossbar of the sheet frame 62 passes through the top of the sheet net 61. When the waves are large, the two ends of the hanging rope 7 can be tied inside the triangular ring 63. At this time, the two ends of the hanging rope 7 can no longer slide, and the triangular fixation is formed by the suspension point, making the shellfish culture cage 6 more stable. When there is no wind or small waves, the two ends of the hanging rope 7 are tied to the top crossbar of the sheet frame 62 and can slide, while the middle is suspended from the hanging frame 4 or the fixed base 31. This allows the shellfish farming cage 6 to swing freely and adjust its posture naturally with the water flow. This ensures sufficient water exchange around the cage, allowing shellfish to filter fish feed and nutrients more efficiently, while reducing rigid collisions between the cage and the enclosure net 32 ​​and the hanging frame 4, thus reducing the risk of structural wear. At the same time, the structure of the top crossbar passing through the top of the sheet net 61, together with the sliding hanging rope 7, can maintain the natural and relaxed shape of the cage, maximizing the space for shellfish farming. When there are large waves, the two ends of the hanging rope 7 are tied to the triangular ring 63 to form a fixed constraint, which, together with the suspension point, forms a triangular fixed structure. The geometric characteristics of the triangle give it a strong resistance to deformation, which can effectively limit the swing amplitude and rotational displacement of the sheet frame 62, preventing the cage from overturning, tearing, or falling off under the impact of wind and waves. This design changes the suspension method of the shellfish cages from flexible swinging to rigid fixing, improving the shellfish farming unit's ability to withstand wind and waves in harsh sea conditions, and ensuring the structural safety of the farming system and the stability of the shellfish's living environment.

[0044] It should be noted that both the triangular ring 63 and the sheet frame 62 are made of stainless steel, and the sheet mesh 61 is made of nylon with a mesh size of 20. The two sheets of sheet mesh 61 cover both sides of the sheet frame 62 respectively, and the ends are sewn together with thread. The sheet mesh 61 is divided into multiple spaces using nylon rope. The preferred dimensions of the sheet frame 62 are 1 meter in length and 0.55 meters in width.

[0045] In some embodiments, the connecting pedal 2 is provided with multiple permeable holes 21 and anti-slip patterns, with the permeable holes 21 having a diameter of 5cm. The anti-slip patterns on the surface of the connecting pedal 2 increase the friction between the sole of the shoe and the surface of the pedal, effectively preventing slips and falls by aquaculture workers even in wet conditions where seawater is present and algae are attached, thus improving personal safety during offshore operations. The permeable holes 21 can quickly drain seawater, rainwater, and aquaculture wastewater from the surface of the pedal, preventing the formation of a water layer on the pedal surface. On the one hand, this eliminates the risk of slipping caused by water accumulation, forming a dual safety protection of anti-slip and drainage with the anti-slip patterns; on the other hand, it prevents the growth of moss and algae on the surface of the pedal due to long-term water accumulation, reducing the need for subsequent manual cleaning and indirectly maintaining the anti-slip performance of the pedal.

[0046] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for marine cage aquaculture of fish and shellfish, characterized in that: Includes the following steps Step 1: Deploy aquaculture cages in nearshore waters, and ensure that the upper part of the enclosure net is above the water surface; Step 2: Place the fish fry into the enclosure net, place the bivalve shellfish into the shellfish culture cage, and suspend the shellfish culture cage inside the culture net box; Step 3: Feed small amounts of supplementary food to the fish periodically. Regularly check the integrity of the mesh of the shellfish farming cage and the coverage of shell attachments. When the shell attachment coverage is less than 30%, rely on the fish to peck at and clean it naturally. If the coverage exceeds 30%, the shellfish farming cage should be lifted out of the water and the shell surface cleaned. After cleaning, it should be hoisted back into place to prevent attachments from affecting the growth of shellfish. The mesh of the shellfish farming cage should be replaced regularly to prevent the mesh from becoming clogged or damaged, which could cause the shellfish larvae to escape. Step 4: In the later stages of aquaculture, fish are caught intermittently by fishing, prioritizing the harvesting of adult fish that exceed the preset length, while keeping individuals smaller than the preset size to continue growing. When the aquaculture cycle ends, the height of the enclosure net is raised to create a closed harvesting space, and then a trawl net is used to drag along the bottom of the aquaculture cages to harvest the remaining adult fish. Subsequently, the shellfish farming cages are lifted out of the water one by one, the mesh nets are disassembled to collect the shellfish, and they are sorted and packed into boxes.

2. The method for fish and shellfish symbiotic marine cage culture according to claim 1, characterized in that: The sheet netting of shellfish farming cages should be replaced every two months, and the integrity of the sheet netting and the coverage of shell attachments should be checked weekly.

3. The method for fish and shellfish symbiotic marine cage culture according to claim 1, characterized in that: The default body length is 25cm.

4. A fish-shellfish symbiotic marine cage aquaculture system, characterized in that: The invention includes aquaculture cages and shellfish aquaculture cages. The aquaculture cages include a fixed base and a perimeter net. The perimeter net is fixedly installed below the fixed base to form a fish aquaculture space. The shellfish aquaculture cages include a sheet-like frame and a sheet-like net. The sheet-like net covers the surface of the sheet-like frame, and the sheet-like nets at both ends of the sheet-like frame are connected to form a shellfish aquaculture space. The shellfish aquaculture space can be divided into multiple spaces, and the shellfish aquaculture cages are suspended inside the perimeter net. It also includes a hanging rope and a triangular ring, the triangular ring being fixedly installed at both ends of the sheet frame, and the two ends of the hanging rope being able to be tied to the sheet frame or to the triangular ring.

5. The fish and shellfish symbiotic marine cage aquaculture system according to claim 4, characterized in that: It also includes a main aquaculture raft, which is fixedly set on the nearshore sea surface, and multiple aquaculture cages are fixedly set inside the main aquaculture raft.

6. The fish and shellfish symbiotic marine cage aquaculture system according to claim 5, characterized in that: It also includes a connecting pedal, which is fixedly disposed between the frame of the main aquaculture raft and the fixed base.

7. The fish and shellfish symbiotic marine cage aquaculture system according to claim 6, characterized in that: The frame of the main aquaculture raft and the fixed base are both formed by splicing plastic pipes. Semi-circular grooves are provided on both sides of the connecting pedal, and the semi-circular grooves can be engaged with the outer circumference of the plastic pipes.

8. The fish and shellfish symbiotic marine cage aquaculture system according to claim 4, characterized in that: It also includes a hanging frame, both of which are square and concentrically arranged with the fixed base. The four corners of the hanging frame are connected to the four corners of the aquaculture net cage by pull ropes. The shellfish aquaculture cages are suspended on both the hanging frame and the fixed base.

9. The fish and shellfish symbiotic marine cage aquaculture system according to claim 4, characterized in that: The fixed base includes a first rectangular fence, a second rectangular fence, and support columns. The second rectangular fence is located above the first rectangular fence, and the first rectangular fence and the second rectangular fence have the same specifications and are concentrically arranged. Multiple support columns are provided, and the two ends of the support columns are fixedly connected to the first rectangular fence and the second rectangular fence, respectively.

10. The fish and shellfish symbiotic marine cage aquaculture system according to claim 6, characterized in that: The connecting pedal is provided with multiple water-permeable holes and anti-slip texture.

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