Three-dimensional ecological culture method of oyster, sea urchin and undaria pinnatifida suitable for silt seabed

Abstract

The present application belongs to the field of mariculture, and particularly relates to a three-dimensional ecological culture method of oysters, sea urchins and Undaria pinnatifida suitable for sandy seabed. The method comprises the following steps: (1) oyster reef construction: oysters are hung in a sandy sea area, and the oysters are put into the seabed to form an oyster reef; (2) Undaria pinnatifida culture: Undaria pinnatifida is cultured above the oyster reef by using a floating raft; (3) sea urchin seed release: the natural pore structure of the oyster reef is used as a habitat for sea urchin seed release; and (4) sinking feeding management: the cultured Undaria pinnatifida is lowered to the sea urchin habitat area on the seabed to serve as sea urchin feed. Compared with the traditional single culture mode, the present application increases the utilization rate of culture space by 3.2 times, reduces the feed cost by 65%, and reduces the nitrogen and phosphorus load of the water body by 40%, while realizing fast growth of sea urchins, improved survival rate of sea urchins, reduced organic matter content in oyster area sediments, and efficient use of fresh Undaria pinnatifida, and has significant economic and ecological benefits.

Description

Technical Field

[0001] This invention belongs to the field of marine aquaculture, specifically relating to a three-dimensional ecological aquaculture method for oysters, sea urchins, and wakame seaweed suitable for muddy or sandy seabeds. Background Technology

[0002] In the marine aquaculture industry, the lack of a stable, hard substrate on muddy or sandy seabeds has become a key bottleneck restricting the large-scale cultivation of benthic organisms such as sea urchins. Existing research shows that traditional net cage farming of sea urchins requires continuous and high costs for equipment maintenance and manual management, while bottom seeding farming suffers from high escape rates and low survival rates due to the inability to provide suitable habitats. Meanwhile, oysters naturally accumulate shells to form ecologically valuable bioreefs, but current aquaculture techniques do not systematically develop the three-dimensional space resources of these reefs, resulting in wasted space and underutilized ecological value. Furthermore, wakame seaweed, a high-quality natural food source for sea urchins, faces challenges with traditional manual harvesting and feeding methods, including high harvesting costs, significant transportation losses, and a 35% uneaten feed rate that poses a risk of bottom pollution, threatening the ecological balance of the aquaculture ecosystem. Currently, research addressing these issues largely focuses on optimizing single-species aquaculture techniques, and a systematic solution based on complementary species niches has not yet been developed.

[0003] Existing technologies (such as CN111758624A) provide habitat for marine delicacies by bottom seeding oyster strings, but still have the following drawbacks: (1) Using oyster strings to directly seed marine delicacies reefs does not provide a solution to the problem of lack of hard substrate in muddy seabeds, and sea urchins still face the problem of unstable habitat and high escape rate in loose mud and sand; (2) The food depends on artificial feeding of other algae, which is not only inefficient, but also does not solve the problem of food shortage in the hot summer season; (3) The oyster string bottom seeding method only realizes the utilization of planar resources and does not develop three-dimensional space, so the ecological benefits are limited. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a three-dimensional ecological aquaculture method for oysters, sea urchins, and wakame seaweed suitable for muddy or sandy seabeds. Compared to traditional single-species aquaculture, this invention increases the utilization rate of aquaculture space by 3.2 times, reduces feed costs by 65%, and decreases nitrogen and phosphorus load in the water by 40%. Simultaneously, it achieves faster sea urchin growth, higher survival rates, reduced organic matter content in sediments in oyster-growing areas, and efficient utilization of fresh wakame seaweed.

[0005] This invention is achieved through the following technical solution: A three-dimensional ecological aquaculture method for oysters, sea urchins, and wakame seaweed suitable for muddy or sandy seabeds, the method comprising the following steps: (1) Oyster reef construction: Oysters are cultured in muddy or sandy sea areas and cultured oysters are placed on the seabed to form oyster reefs; (2) Wakame cultivation: Wakame is cultivated on the oyster reef using floating rafts; (3) Sea urchin seedling release: Sea urchin seedlings are released using the natural porous structure of the oyster reef as a habitat for sea urchins; (4) Settling feeding management: The farmed wakame seaweed is lowered to the sea urchin habitat area on the seabed as sea urchin food.

[0006] Furthermore, step (1) specifically includes: (1.1) Aquaculture raft deployment: In muddy and sandy sea areas, single aquaculture rafts are deployed in parallel at 6-8m intervals. The net length of the floating rod of each single aquaculture raft is 60-80m. The floating rod is fixed to the seabed by pile cables and deep-inserted supports. Several buoys are tied to the raft. (1.2) Oyster hanging culture: Select the Pacific oyster as the cultured species, use oyster shells or shells as attachment substrates for seed collection, and culture the juvenile oysters attached to the attachment substrates until the shell length reaches 500-600μm before transferring them to natural sea areas and hanging them on floating twigs at an interval of 8-15cm between attachment substrates. During harvesting, the ends of 10-15 aquaculture ropes are tied together and then fixed to the seabed with wooden stakes. (1.3) Reef formation: After several years of continuous oyster farming, the oysters grow and attach themselves, and their shells accumulate to form oyster reefs.

[0007] Further, in step (1.1), the deep-insertion bracket is characterized by being made of traditional wooden stakes, corrosion-resistant metals, or high-strength engineering plastics.

[0008] Furthermore, in step (1.3), after 2-3 consecutive years of oyster farming, the oyster farming ropes are deployed. After underwater observation and confirmation, when the oyster reef height protrudes ≥50cm above the seabed mud and sand surface and the porosity is ≥60%, the oyster reef construction work is completed.

[0009] Furthermore, step (2) specifically includes: (2.1) Autumn seedling cultivation of wakame: After the oyster reef is built, when the sea temperature drops to <20℃ in late September each year, wakame sporophyte seedling ropes are hung horizontally between two adjacent rows of floating rafts that have been deployed, with a horizontal cultivation density of 20-30 plants / meter. (2.2) Spring seedling cultivation of wakame: In mid-to-late February each year, supplement wakame gametophyte seedlings for raft cultivation, with a density of 20-30 plants / meter for flat cultivation.

[0010] Furthermore, the rafts used for cultivating wakame seaweed are made of polyethylene material.

[0011] Furthermore, step (3) specifically includes: (3.1) Selection of sea urchin seedlings: Select sea urchins such as Ezo-mafumi or purple sea urchins as the culture targets; The species to be released should be selected according to the temperature of the sea area. When the temperature of the sea area exceeds 25℃, purple sea urchins should be seeded on the bottom; when the temperature of the sea area does not exceed 25℃, horse manure sea urchins should be seeded on the bottom. (3.2) Sea urchin seedling release: Sea urchin seedlings are released into the sea using the natural porous structure of the oyster reef as a habitat for sea urchins; Avoid releasing sea urchin seedlings during the high-temperature period of summer. Release them in late November to early December when the water temperature drops below 15℃. The seedling size should be 30-50g / seedling with a shell diameter of 2.5-3.5cm, and the stocking density should be 15-20 seedlings / m².

[0012] Furthermore, step (4) specifically includes: When the cultivated wakame algae grow to ≥50cm, untie part of the cultivation ropes of the wakame, and connect the middle part of 3-5 cultivation ropes to the sinker with a tie rope, so that the cultivation ropes of the wakame can naturally fall to the sea urchin habitat area on the seabed and serve as food for the sea urchins. Adjust the feeding frequency and amount according to the actual feeding situation of the sea urchins to ensure that the food supply matches the needs of the sea urchins.

[0013] Furthermore, when feeding sea urchins with the aforementioned wakame seaweed, the feeding amount should be 8-10% of the sea urchin's body weight per day.

[0014] Beneficial technical effects of the present invention: The three-dimensional ecological aquaculture method provided by this invention innovates the habitat pattern of sea urchins, abandons the traditional artificial framework, and uses the natural structure of oyster reefs to provide habitat for sea urchins, saving about 40% of equipment costs and increasing the survival rate of sea urchins from 30% in the traditional bottom seeding method to more than 85%.

[0015] The three-dimensional ecological aquaculture method provided by this invention innovates the feed supply. By cultivating and releasing wakame seedlings (sporophyte seedlings and gametophyte seedlings) in spring and autumn, a year-round feed supply can be achieved, eliminating the need for manual harvesting and increasing the feed utilization rate from 65% to 88%.

[0016] The three-dimensional ecological aquaculture method provided by this invention has significant ecological benefits, reducing the pollution of the marine environment by artificial frame materials, effectively reducing the nitrogen and phosphorus load in the water and the organic matter content in the sediment, and maintaining the ecological balance of the aquaculture area. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of wakame cultivation in an embodiment of the present invention; Figure 2 This is an underwater side view schematic diagram of an oyster-sea urchin-wakame three-dimensional ecological aquaculture suitable for muddy and sandy seabeds in an embodiment of the present invention; Attached reference numerals: 1. Buoy; 2. Floating rod; 3. Pile cable; 4. Deep-insertion support; 5. Wakame seaweed; 6. Raft; 7. Oyster; 8. Sea urchin; 9. Oyster reef. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0020] This invention provides a three-dimensional ecological aquaculture method for oysters, sea urchins, and wakame seaweed suitable for muddy or sandy seabeds, the method comprising the following steps: (1) Oyster reef construction: Oysters are cultured in muddy or sandy sea areas and cultured oysters are placed on the seabed to form oyster reefs; (2) Wakame cultivation: Wakame is cultivated on the oyster reef using floating rafts; (3) Sea urchin seedling release: Sea urchin seedlings are released using the natural porous structure of the oyster reef as a habitat for sea urchins; (4) Settling feeding management: The farmed wakame seaweed is lowered to the sea urchin habitat area on the seabed as sea urchin food.

[0021] Step (1) specifically includes: (1.1) Aquaculture raft deployment: In muddy and sandy sea areas, single aquaculture rafts are deployed in parallel at intervals of 6-8m. The net length of the floating rod 2 of each single aquaculture raft is 60-80m. The floating rod 2 is fixed to the seabed by the pile cable 3 and the deep-inserted support 4. Several buoys 1 are tied to the raft. Specifically, the deep-inserted support 4 is made of traditional wooden piles, corrosion-resistant metal or high-strength engineering plastic.

[0022] (1.2) Oyster hanging culture: Select the fast-growing and highly adaptable Pacific oyster as the culture species, use oyster shells or shells as attachment substrates (the surface of the attachment substrate has holes for ropes to be threaded through, and a rope is installed inside); collect seedlings, and after the juvenile oysters attached to the attachment substrate are cultured to a shell length of 500-600μm, they are transferred to the natural sea area and hung on floating twigs at a spacing of 8-15cm between attachment substrates; During harvesting, the ends of 10-15 aquaculture ropes are tied together and then fixed to the seabed with wooden stakes. Specifically, the oyster farming ropes used in hanging culture are divided into upper and lower sections. The upper section of the farming rope is 3 meters long, and the oysters attached to it are harvested as commercial oysters after they have grown. The lower section of the farming rope is 2 meters long. When harvesting, the ends of every 10-15 farming ropes are tied together and fixed to the seabed with wooden stakes to serve as materials for building oyster reefs.

[0023] (1.3) Reef Formation: After several years of continuous deployment of cultured oyster farming ropes, the oysters grow and attach, and their shells accumulate to form an oyster reef. Specifically, after 2-3 years of continuous deployment of cultured oyster farming ropes, and confirmed by diving observation, when the oyster reef height protrudes ≥50cm above the seabed mud and sand surface (i.e., oyster reef height ≥50cm) and the porosity is ≥60%, the oyster reef construction is complete. The oyster reef fixing method used in this invention is suitable for muddy and sandy geology, is relatively stable, and is eco-friendly.

[0024] In this embodiment, step (2) specifically includes: (2.1) Autumn seedling cultivation of wakame: After the oyster reef is built, when the sea temperature drops to <20℃ in late September each year, wakame sporophyte seedling ropes are hung horizontally between two adjacent rows of floating rafts that have been deployed, with a horizontal cultivation density of 20-30 plants / meter; among them, the floating rafts used for cultivating wakame are made of high-strength, corrosion-resistant polyethylene material.

[0025] (2.2) Spring seedling cultivation of wakame: In mid-to-late February each year, wakame gametophyte seedlings are added for raft cultivation, with a density of 20-30 plants / meter in the flat cultivation. During the seedling cultivation process, environmental parameters such as water quality and light are monitored regularly to regulate the growth conditions of wakame and ensure its healthy growth.

[0026] In this embodiment, step (3) specifically includes: (3.1) Selection of sea urchin seedlings: Select sea urchins with fast growth rate and high economic value, such as Ezo-mafumi sea urchins or purple sea urchins, as the aquaculture targets; The species to be released should be selected according to the temperature of the sea area. When the temperature of the sea area exceeds 25℃, purple sea urchins should be seeded on the bottom; when the temperature of the sea area does not exceed 25℃, horse manure sea urchins should be seeded on the bottom. (3.2) Sea urchin seedling release: Sea urchin seedlings are released into the sea using the natural porous structure of the oyster reef as a habitat for sea urchins; Avoid releasing sea urchin larvae during the high temperatures of summer. Release them in late November to early December when the water temperature drops below 15℃. The larvae should be 30-50g each with a shell diameter of 2.5-3.5cm, at a stocking density of 15-20 larvae / m². Specifically, when releasing the larvae, secure them with rope and place them on the seabed as initial food for the bottom-sown sea urchins.

[0027] In this embodiment, step (4) specifically includes: When the cultivated wakame thallus grows to ≥50cm (sporophyte seedlings reach ≥50cm around late November, and gametophyte seedlings reach ≥50cm around late May), loosen some of the wakame cultivation ropes and connect the middle part of 3-5 cultivation ropes to weights greater than 500g each by tying ropes, allowing the wakame cultivation ropes to naturally droop down to the sea urchin habitat area on the seabed as food for the sea urchins; adjust the feeding frequency and amount according to the actual feeding situation of the sea urchins to ensure that the food supply matches the needs of the sea urchins; maintain the material cycle and ecological balance of the cultivation system.

[0028] In this invention, the autumn wakame seedlings cultivated in mid-to-late September each year can be fed from late November until late May of the following year; the spring wakame seedlings cultivated in mid-to-late February each year can be fed from late May until late November; the spring-cultivated wakame seedlings fully utilize the vacant space after the autumn wakame harvest, while also addressing the shortage of high-quality feed for bottom-seeded sea urchins after June, thus improving the survival rate of sea urchins during the summer. Through the cultivation and release of double-season wakame seedlings (sporophyte seedlings and gametophyte seedlings) in spring and autumn, a year-round feed supply is achieved, eliminating the need for manual harvesting and increasing the feed utilization rate from 65% to 88%. During the feeding period, sea urchins that reach marketable size are harvested by catching the larger ones and leaving the smaller ones.

[0029] In this invention, if fresh wakame seaweed is unavailable, ropes containing gynostemma pentaphyllum or floating seaweed are dropped onto the seabed for feeding. Specifically, during periods of high temperature, ropes containing gynostemma pentaphyllum can be dropped onto the seabed, while during periods of low temperature, ropes containing floating seaweed can be dropped onto the seabed to feed sea urchins.

[0030] In this embodiment, when feeding sea urchins with the aforementioned wakame seaweed, the feeding amount is 8-10% of the sea urchin's body weight per day.

[0031] The implementation area was selected as the silty and sandy sea area of ​​Sangou Bay in Rongcheng, Shandong (water depth 10m). The specific implementation steps are as follows: (I) Oyster Reef Foundation Construction In the Sangou Bay aquaculture area, five parallel rows of single-unit aquaculture rafts for wakame (or kelp) were selected as the implementation area.

[0032] In June 2023, the Pacific oyster was selected as the cultured species. Scallop shells were used as attachment substrates for indoor artificial collection of oyster seedlings. Once the attached juveniles reached a shell length of 550 μm, they were transferred to natural sea areas. A longline hanging culture method was adopted, with attachment substrates spaced 10 cm apart. The hanging rope consisted of a 3m upper section and a 2m lower section. Oyster seedlings were stocked at a density of 350 per rope. During the culture process, environmental parameters such as water temperature, salinity, and dissolved oxygen were monitored regularly.

[0033] In September 2024, the ends of 10 aquaculture ropes were tied together and fixed to the seabed with wooden pegs. At this time, the oyster shells piled up on each other, forming an oyster reef with an average height of 50cm and a porosity of ≥60%, laying the foundation for subsequent aquaculture.

[0034] (II) Seaweed sporophyte seedlings In October 2024, wakame sporophyte seedlings (autumn wakame seedlings) were hung horizontally between the floating rafts. The seedlings were 15cm in size when they were placed in the sea, and the seedling density was 20 plants / meter. During the cultivation period, water quality, light and other parameters were monitored according to the growth.

[0035] (III) Release of sea urchin seedlings In November 2024, due to the temperature in the Sangou Bay sea area being below 25℃, the sea urchin was selected as the aquaculture target. The seedlings were released at a size of 30g / each (shell diameter of about 2.5cm) at a density of 18 per m², and were directly dispersed into the natural porous structure of the oyster reef group to make full use of the reef space to provide habitat for the sea urchins.

[0036] (iv) Feeding Management In late November, when the wakame thallus grows to over 50cm, some of the wakame cultivation ropes are untied. The middle section of 3-5 seedling ropes is then tied to a 500g weight, allowing them to naturally dangle into the sea urchin habitat. The sea urchins are fed 8% of their body weight daily, with the feeding frequency dynamically adjusted based on their feeding behavior to achieve efficient food utilization.

[0037] (v) Supplementation of wakame gametophyte seedlings In February 2025, wakame gametophyte seedlings (wakame spring seedlings) were released into the sea for cultivation. During the cultivation process, the same marine aquaculture management methods as for sporophyte seedlings were used. By regularly monitoring water quality parameters such as pH, salinity, nitrogen and phosphorus content, as well as light intensity and water temperature, aquaculture conditions such as raft position and seedling rope density were adjusted in a timely manner to continuously optimize the growth environment of the gametophyte seedlings.

[0038] By mid-to-late May 2025, all sporophyte seedlings cultured in the early stages had completed feeding as planned. At this time, the gametophyte seedlings had grown to 60 cm, reaching the suitable feeding length. Following the established feeding method, some of the gametophyte seedling cultivation ropes were untied, and the middle section of 3-5 seedling ropes was tied with a rope to a 500g weight, allowing them to naturally dangle into the sea urchin habitat on the seabed as food. Simultaneously, the feeding frequency and amount were dynamically adjusted based on the actual feeding behavior of the sea urchins to ensure that the food supply matched their needs, further maintaining the material cycle and ecological balance within the aquaculture system.

[0039] (vi) Sea urchin harvest Starting in June 2025, sea urchins that have reached commercial size will be harvested. The commercial size is defined as a weight ≥ 80g and a shell diameter ≥ 4.5cm. Harvesting will be done manually by diving, following the principle of "harvesting the large and leaving the small," prioritizing the harvesting of sea urchins that meet the size requirements while allowing smaller individuals to continue growing. During the harvest, the quantity and weight of sea urchins harvested will be recorded, and the remaining sea urchin population and their growth status in the aquaculture area will be assessed to inform the planning of subsequent aquaculture management strategies.

[0040] (vii) Implementation Results After one breeding cycle of practice, this ecological breeding method has achieved remarkable results: Sea urchin farming efficiency improved: The survival rate of sea urchins increased to 92%, compared to 78% in traditional net cage farming, which significantly improved the survival rate and effectively reduced farming risks; Environmental improvement: The organic matter content of sediments in the oyster area decreased by 41%, indicating that the filter feeding of oysters effectively purified the water quality in the aquaculture area and improved the seabed environment; Highly efficient use of resources: The utilization rate of wakame residue reaches 85%, which reduces the pollution of water bodies by residue, while providing high-quality natural food for sea urchins, realizing material cycle and ecological balance within the aquaculture system.

[0041] This invention provides a three-dimensional ecological aquaculture method that synergizes the ecological niche utilization of oyster reefs, the habitat requirements of sea urchins, and the food value of wakame seaweed, constructing an aquaculture model that is both economically efficient and environmentally friendly. The artificially constructed oyster reefs significantly improve the attachment stability of sea urchins, effectively solving the problems of unstable habitat and high escape rates faced by sea urchins in loose mud. Simultaneously, the innovative use of "double-cropping wakame seaweed," alternating between autumn seedlings (feeding in November) and spring seedlings (supplemented in February of the following year), not only solves the food shortage problem for sea urchins during the high-temperature period from June to August, but also allows naturally falling wakame seaweed residue to be consumed by oysters and sea urchins, increasing the food utilization rate from 65% to 88% and reducing labor costs by 65%. Furthermore, wakame seaweed can absorb nitrogen and phosphorus from the water during aquaculture, synergizing with the filter-feeding action of oysters to effectively regulate water quality and significantly improve ecological benefits.

[0042] This invention creatively utilizes artificially constructed bio-reefs formed by the accumulation of cultured adult oysters to solve the problem of sea urchins' inability to be bottom-seeded due to a lack of hard attachment substrates. It also achieves material cycling within the aquaculture system through a nutrient cascade between wakame and sea urchins. This method, through three core steps—oyster reef construction, sea urchin three-dimensional habitat construction, and wakame feeding system integration—forms a three-dimensional ecological aquaculture model of "attached organisms-benthic organisms-macro algae." Compared to traditional single-species aquaculture models, this invention increases aquaculture space utilization rate by 3.2 times, reduces feed costs by 65%, and decreases nitrogen and phosphorus loads in the water by 40%. Simultaneously, it achieves faster sea urchin growth, higher survival rates, reduced organic matter content in oyster-covered sediments, and efficient utilization of fresh wakame, resulting in significant economic and ecological benefits. This provides a sustainable technical solution for marine aquaculture in muddy and sandy sea areas.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A three-dimensional ecological aquaculture method for oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds, characterized in that... The method includes the following steps: (1) Oyster reef construction: Oysters are cultured in muddy and sandy sea areas. The cultured oysters are continuously placed on the oyster culture ropes. The oysters grow and attach, and the shells accumulate to form oyster reefs. The height of the oyster reefs protrudes from the muddy and sandy sea surface by ≥50cm and the porosity is ≥60%. (2) Wakame culture: Wakame is cultured on the oyster reef using floating rafts; the wakame culture includes autumn seedling culture and spring seedling culture. Autumn seedling culture is carried out by hanging wakame sporophyte seedlings on ropes when the sea temperature drops to <20℃ in late September each year. Spring seedling culture is carried out by supplementing wakame gametophyte seedlings for raft culture in mid-to-late February each year. (3) Sea urchin seedling release: Sea urchin seedlings are released using the natural porous structure of the oyster reef as a habitat for sea urchins; (4) Settling feeding management: When the thallus of the cultivated wakame grows to ≥50cm, untie part of the cultivation rope of the wakame and connect the middle part of 3-5 cultivation ropes to the sinker with a rope, so that the cultivation rope of the wakame will naturally fall to the sea urchin habitat area on the seabed as food for the sea urchins.

2. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1, characterized in that, The oyster reef construction in step (1) specifically includes: (1.1) Aquaculture raft deployment: In muddy and sandy sea areas, single aquaculture rafts are deployed in parallel at 6-8m intervals. The net length of the floating rod of each single aquaculture raft is 60-80m. The floating rod is fixed to the seabed by pile cables and deep-inserted supports. Several buoys are tied to the raft. (1.2) Oyster hanging culture: Select the Pacific oyster as the culture species, use oyster shells or shells as attachment substrates for seed collection, and culture the juvenile oysters attached to the attachment substrates until the shell length reaches 500-600μm before transferring them to natural sea areas. Hang them on floating rods at an interval of 8-15cm between attachment substrates. When harvesting, tie the ends of 10-15 culture ropes together and fix them to the seabed with wooden stakes.

3. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 2, characterized in that, In step (1.1), the deep-insertion bracket is made of traditional wooden stakes, corrosion-resistant metal or high-strength engineering plastic.

4. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1, characterized in that, In step (1), after 2-3 consecutive years of oyster farming ropes are deployed and the oyster reef construction work is completed after underwater observation confirms that the oyster reef meets the standards described in step (1).

5. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1, characterized in that, In step (2), the density of the autumn seedlings raised on the ground is 20-30 plants / meter, and the density of the spring seedlings raised on the ground is 20-30 plants / meter.

6. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1 or 5, characterized in that, The rafts used for cultivating wakame seaweed are made of polyethylene.

7. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1, characterized in that, Step (3) specifically includes: (3.1) Selection of sea urchin seedlings: Select sea urchins such as Ezo bafen or purple sea urchins as the aquaculture targets; select the species to be released according to the sea temperature. When the sea temperature exceeds 25℃, bottom seed purple sea urchins are used; when the sea temperature does not exceed 25℃, bottom seed bafen sea urchins are used. (3.2) Sea urchin seedling release: Utilizing the natural porous structure of the oyster reef as a habitat for sea urchins, sea urchin seedlings are released. Release should be avoided during the high-temperature summer period, and should be carried out from late November to early December when the water temperature drops below 15℃. The seedling size is 30-50g / seedling, with a shell diameter of 2.5-3.5cm, and the stocking density is 15-20 seedlings / m². 2 .

8. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1, characterized in that, In step (4), the feeding frequency and amount are adjusted according to the actual feeding status of the sea urchins to ensure that the feed supply matches the needs of the sea urchins.

9. The method for integrated ecological aquaculture of oysters, sea urchins, and wakame seaweed on muddy or sandy seabeds according to claim 1 or 8, characterized in that, When feeding sea urchins with the aforementioned wakame seaweed, the feeding amount should be 8-10% of the sea urchin's body weight per day.

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