Multi-nutrition-level culture mode suitable for brackish water pond and application of multi-nutrition-level culture mode

Abstract

The invention belongs to the field of aquaculture, and particularly relates to a multi-nutrition-level aquaculture mode suitable for a brackish water pond and application of the multi-nutrition-level aquaculture mode. According to the method, a multi-nutrition-level ecological breeding mode with scylla paramamosain, penaeus vannamei, ostrea rivularis and gracilaria tenuifolia as core breeding objects is constructed, and the variety specification, density, stocking time and water quality regulation and control strategies are standardized; the problems that a brackish water pond culture mode is single, the culture technology falls behind, and the culture surrounding environment is greatly stressed are effectively solved, and the purposes of water area space complementation, bait complementation, high utilization rate, ecological disease prevention and nitrogen and phosphorus cyclic utilization between animals and plants of different nutrition levels and different culture ecological niches are achieved. Results of the embodiment show that by means of the breeding method, the water quality of the pond can be effectively guaranteed, diseases of various economic varieties are reduced, antibiotics are not used in the whole process, and the comprehensive yield and the comprehensive benefits of breeding are improved.

Description

Technical Field

[0001] The invention belongs to the field of aquaculture, and in particular relates to a multi-trophic level aquaculture model suitable for brackish water ponds and an application thereof. Background Art

[0002] Integrated Multi-Trophphic Aquaculture (IMTA) is a healthy aquaculture model in the aquaculture industry. Its core principle is to utilize the differences in ecological niches of different aquaculture species and the nutritional relationships between aquaculture organisms to convert the waste discharged by one organism into a nutrient source for another organism, thereby achieving multiple recycling of nutrients, reducing the output of harmful substances, making full use of aquaculture space, and improving the utilization efficiency of energy and materials in the system. At present, the IMTA aquaculture model has been regarded as an important development direction for the future aquaculture industry by China, Canada, the United States, New Zealand, Norway and other countries.

[0003] Southern my country, such as Guangdong Province, Fujian Province, Guangxi Zhuang Autonomous Region, Hainan Province, etc., are all fishery and aquaculture areas, and they develop in a coordinated manner in marine aquaculture and freshwater aquaculture. In 2023, the total aquaculture area in China is 7.625 million hectares, while the aquaculture area in Guangdong Province is 477,000 hectares, of which marine aquaculture accounts for 36.1% and pond aquaculture accounts for 54.3%. Most of the aquaculture ponds in Guangdong are brackish water ponds built in the estuary area of ​​the sea. The main aquaculture species include: white shrimp, Japanese shrimp, mud crab, oyster, mussel, gracilaria, sea bass, yellowfin seabream, grass carp, tilapia, grouper, etc.

[0004] At present, brackish water pond aquaculture has the disadvantages of single aquaculture mode, backward aquaculture technology, and great pressure on the environment. Therefore, a new aquaculture mode needs to be developed to improve the above disadvantages. However, although IMTA, as an innovative aquaculture mode, has shown significant advantages in improving resource utilization efficiency and promoting ecological balance, it still faces many challenges in its application in actual aquaculture production, including the complexity of technical implementation, aquaculture survival rate, aquaculture ecological impact, economic benefits and sustainable development. Summary of the invention

[0005] The purpose of the present invention is to construct a multi-trophic level ecological breeding model of mud crab-whiteleg shrimp-Omi oyster-Gracilaria tenuifolia suitable for brackish water ponds. The breeding model provided by the present invention can not only effectively solve the problems of single breeding model in brackish water ponds, backward breeding technology, and great pressure on the breeding environment, but also achieve the goals of spatial complementarity of water areas, complementary baits and high utilization rate, ecological disease prevention and nitrogen and phosphorus recycling between animals and plants at different nutritional levels and different breeding ecological niches.

[0006] The technical solution provided by the present invention is as follows:

[0007] A multi-trophic level culture model for brackish water ponds that includes the following processes:

[0008] 1) Preparation of aquaculture ponds, including dredging, disinfection, building aquaculture rafts, filling water, and adding biofertilizers and probiotics to fertilize the water;

[0009] 2) Test the water quality of aquaculture water, including water temperature, salinity, pH, dissolved oxygen, ammonia nitrogen, hydrogen sulfide, nitrite, phosphate, total nitrogen and total phosphorus, and adjust the water quality to the following range: water temperature is maintained between 20-30℃; salinity is maintained between 8-15‰; pH value is between 7.5-8.3; dissolved oxygen content is higher than 5mg / L; ammonia nitrogen content is lower than 0.3mg / L; hydrogen sulfide content is lower than 0.002mg / L; nitrite content is lower than 0.02mg / L; phosphate content is lower than 0.05mg / L; total nitrogen content is lower than 40.0mg / L; total phosphorus content is lower than 2.0mg / L.

[0010] 3) Establish a multi-trophic level aquaculture model, and stock economic species suitable for brackish water in phases and batches, including mud crabs, white shrimp, oysters and Gracilaria tenuifolia;

[0011] 4) Stock a small amount of yellowfin seabream in the pond;

[0012] 5) Carry out breeding management work and nutritional quality testing of breeding varieties, and conduct quality analysis of breeding products.

[0013] Furthermore, step 1) of preparing the breeding pond also includes: pond cleaning and repairing, the repairing including reinforcing and raising the pond, compacting the bank to avoid bank collapse and soil erosion; setting up water inlets and outlets; setting up fences around the pond to prevent the mud crabs from escaping.

[0014] Furthermore, the desilting in step 1) is to drain the pond water in winter or spring and remove the silt above 10 cm on the surface of the pond bottom.

[0015] Furthermore, the disinfection method in step 1) is to freeze the pond for 1-3 months, and then about 30 days before stocking, use 80-100 kg (per mu) of quicklime, add water to make a slurry, and then sprinkle it over the entire pond while it is still hot, and then evenly plow the bottom mud to kill pathogens and improve the bottom quality.

[0016] Furthermore, the biological fertilizer in step 1) also includes phosphate fertilizer, potash fertilizer, urea, molasses and amino acid preparations, and the mixed biological fertilizer is added to the pond every 20-25 days to promote the growth and reproduction of microalgae.

[0017] Furthermore, the probiotics in step 1) are Chlorella, Chaetoceros, Nitzschia closterium and EM bacteria.

[0018] Furthermore, the probiotics are added in step 1) by fermentation and spraying EM bacteria, using 500g EM bacterial agent, 1000g brown sugar and 50 jin of sterile and non-toxic water for 2-3 days before use, and 3-4 jin of fermentation liquid is used per mu of pond in summer; a mixed algae liquid with a mass concentration of 10% is added to the pond, and the mixed algae liquid includes Chlorella and Chaetoceros, and is sprayed at a water depth of 2 liters / mu·m. In autumn and winter, the crescent-shaped algae liquid is sprayed at a density of 10 million / mL, and is sprayed at 4 liters / mu·m, and the fertilizer water preparation is sprayed at 4 kg / mu for the cultivation of water algae. Probiotics are used once every two weeks to adjust the transparency of the water body, stabilize the water quality and water color, and avoid the phenomenon of thin water color and the growth of moss and mud skin.

[0019] Furthermore, in step 3), the farming method of the economic species is as follows: Gracilaria tenuifolia is farmed by a seine net and rope method, and is farmed separately from Crassostrea gigas; commercial shrimp and crab feed is fed to shrimps and blue crabs; residual bait that is not eaten in time sinks to the bottom of the pond and can still be eaten by benthic blue crabs; residual bait particles dissolved in the water can also be filtered and eaten by Crassostrea gigas; substances such as nitrogen and phosphorus in the farming water can be absorbed and utilized by large seaweed and microalgae.

[0020] Further, in step 3), the specifications, density, feed types and feeding amount of economic species are as follows: the stocking specification of whiteleg shrimp is about 1.0 cm / tail, and the density is about 10,000 tails / mu; the stocking specification of mud crab is crab II seedlings, and the density is 500-800 / mu; large-sized individuals of Omi oysters are stocked for fattening, and the density is 70-100 kg / mu; the breeding density of fine-based Gracilaria is 30 kg / mu, and the whole breeding process is mainly fed with commercial shrimp and crab feed, supplemented with some red meat basket clams, and chlorella and diatoms (horn algae and crescent algae) are sprinkled from time to time. Shrimp and crab feed is fed according to 3-10% of the body weight of shrimp and crab, and regular sampling and weight measurement are carried out to track growth and feeding conditions, and the feeding amount is adjusted appropriately, and water samples are regularly drawn for testing, and the water color and algae phase of the water body are observed, and chlorella and diatoms and water fertilizer preparations are appropriately supplemented.

[0021] Furthermore, in step 3), the order of stocking economic species is as follows: first, blue crab seedlings and white shrimp seedlings are stocked, one month later, Omi oysters are stocked, and yellowfin sea bream is stocked after another half a month, and fine-based Gracilaria is released according to water quality conditions.

[0022] Furthermore, in step 4), the yellowfin seabream is cultured at an average number of 20-30 per acre to prey on sick and slow-moving shrimps to prevent infected individuals from infecting each other.

[0023] Furthermore, the method for regulating water quality in step 2) is: according to the specific conditions of the water quality, different substances and probiotics are added to improve the water quality. When the pH is less than 7.5, 15 kg / mu of quicklime is sprayed throughout the pond; when the pH is greater than 8.5, 500 mL / mu of acetic acid is sprayed throughout the pond; when the ammonia nitrogen content is greater than 0.4 mg / L, 15 kg / mu of zeolite powder is applied in the morning on a sunny day, and photosynthetic bacteria (live bacteria content of about 3×10 9 / milliliter) 3L / mu; when the nitrite content is greater than 0.03mg / L, first use nitrite antidote 1500g / mu (after dilution with water) to spray the whole pond, and then directly spray 1kg / mu of fast-acting oxygenator; when the hydrogen sulfide content is greater than 0.003mg / L, use an oxidant to oxidize hydrogen sulfide into sulfate; when the dissolved oxygen is less than 4mg / L, spray the oxygenator calcium peroxide throughout the pond.

[0024] Furthermore, in step (5), aquaculture management and nutritional quality testing of aquaculture varieties are carried out, including: testing the feeding and feeding status of commercial shrimp feed, so as to formulate a reasonable feeding strategy. It is also necessary to master certain rules when feeding, and feed strictly in accordance with the "three fixed" principles of timing, quantity and location. The specific feeding process should also be adjusted in combination with the weather, the feeding status of shrimps and blue crabs, the water conditions, etc. When the weather is relatively good, appropriate feed can be added. In rainy weather, the amount of feed should be reduced accordingly. In hot weather, the number of daytime feed feedings should be reduced, and feeding should be carried out when the temperature is low, which is conducive to the digestion and absorption of feed by shrimps and blue crabs.

[0025] Furthermore, in step (5), the product quality analysis includes measuring the body length and weight of whiteleg shrimp, the carapace length, carapace width and weight of mud crab, the weight of Crassostrea gigas, and the yield of Gracilaria tenuifolia, and detecting the protein, fat levels, amino acid content and fatty acid content of the above-mentioned farmed products.

[0026] Beneficial effects:

[0027] The present invention combines brackish water pond farming with a multi-trophic level farming model, which can effectively solve the problems of a single brackish water pond farming model, backward farming technology, and great pressure on the surrounding environment of farming, and achieves the goals of efficient use of nutrients and energy, rational use of space, and increased comprehensive benefits.

[0028] The multi-trophic level aquaculture model suitable for brackish water ponds described in the present invention can improve the aquaculture biodiversity of brackish water ponds and promote the harmonious development of man and nature; it can also solve the problems of water space complementarity, bait complementarity and high utilization rate, ecological disease prevention, nitrogen and phosphorus recycling, etc. between animals and plants at different trophic levels and different aquaculture ecological niches. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 This is a flow chart of the multi-trophic level farming model.

[0031] Figure 2 This is a schematic diagram of the multi-trophic level farming model.

[0032] Figure 3 Schematic diagram of the change of water temperature in the experimental group and the control group over time in the embodiment

[0033] Figure 4 Schematic diagram of the change of salinity in the water of the experimental group and the control group over time in the embodiment

[0034] Figure 5 Schematic diagram of pH change in the water of the experimental group and the control group over time in the embodiment

[0035] Figure 6 Schematic diagram of the change of dissolved oxygen content in the water body in the experimental group and the control group over time in the embodiment

[0036] Figure 7 Schematic diagram of the change of ammonia nitrogen content in water of the experimental group and the control group over time in the embodiment

[0037] Figure 8 Schematic diagram of the change of hydrogen sulfide content in water in the experimental group and the control group over time in the embodiment

[0038] Fig. 9 Schematic diagram of the change of nitrite content in water of the experimental group and the control group over time in the embodiment

[0039] Fig.10 Schematic diagram of the change of phosphate content in water of the experimental group and the control group over time in the embodiment

[0040] Fig.11 Schematic diagram of the change of total nitrogen content in water bodies in the experimental group and the control group over time in the embodiment

[0041] Fig.12 Schematic diagram of the change of total phosphorus content in water bodies in the experimental group and the control group over time in the embodiment DETAILED DESCRIPTION

[0042] The present invention provides a multi-trophic level aquaculture model suitable for brackish water ponds, and the process of the aquaculture model includes: 1) preparing aquaculture ponds, including dredging, disinfection, building aquaculture rafts, water intake, and adding fertilizers and probiotics; 2) detecting the water quality of aquaculture water, including water temperature, salinity, pH, dissolved oxygen, ammonia nitrogen, hydrogen sulfide, nitrite, phosphate, total nitrogen and total phosphorus; 3) building a multi-trophic level aquaculture model, and stocking economic species suitable for brackish water life, including mud crabs, white shrimps, oysters and Gracilaria tenuifolia; 4) releasing yellowfin seabream into the pond; 5) performing product quality analysis on the aquaculture products.

[0043] The water quality for breeding the fish in the present invention is as follows: the water temperature is maintained between 20-30°C; the salinity is maintained between 8-15‰; the pH value is between 7.5-8.3; the dissolved oxygen content is higher than 5mg / L; the ammonia nitrogen content is lower than 0.3mg / L; the hydrogen sulfide content is lower than 0.002mg / L; the nitrite content is lower than 0.02mg / L; the phosphate content is lower than 0.05mg / L; the total nitrogen content is lower than 40.0mg / L; and the total phosphorus content is lower than 2.0mg / L.

[0044] Preferably: the water temperature is maintained between 22-26°C; the salinity is maintained between 8-12‰; the pH value is between 7.5-8.3; the dissolved oxygen content is higher than 6 mg / L; the ammonia nitrogen content is lower than 0.2 mg / L; the hydrogen sulfide content is lower than 0.002 mg / L; the nitrite content is lower than 0.01 mg / L; the phosphate content is lower than 0.05 mg / L; the total nitrogen content is lower than 25.0 mg / L; and the total phosphorus content is lower than 1.0 mg / L.

[0045] The flow chart of the multi-trophic level aquaculture model suitable for brackish water ponds of the present invention is as follows: Figure 1 The schematic diagram of the multi-trophic level aquaculture model suitable for brackish water ponds according to the present invention is as shown in Figure 2 shown.

[0046] In order to further illustrate the present invention, the multi-trophic level culture model suitable for brackish water ponds provided by the present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0047] Example 1

[0048] Preparation work was carried out before stocking the brackish water ponds in the Niutianyang breeding area of ​​Shantou City, including pond renovation, pond cleaning, fertilization, etc. The ponds were divided into experimental ponds and control ponds. Each pond was repaired, the bank was reinforced, heightened, and compacted to avoid bank collapse and soil erosion; water inlets and drainage outlets were set up. The ponds were surrounded by fences to prevent the mud crabs from escaping.

[0049] Drain the pond water in winter and remove the silt more than 10 cm above the surface of the pond bottom. After about 2 months of winter freezing and drying, about 30 days before stocking economic varieties, use 80-100 kg / mu of quicklime, add water to make a slurry, and then sprinkle it all over the pond while it is hot. Then evenly plow the bottom mud to kill pathogens and improve the pond bottom.

[0050] Pond water is injected from April to June. The initial water quality requirements for the experimental pond and the control pond are: pond water temperature between 22-26℃; salinity between 8-12‰; pond pH value is alkaline, between 7.5-8.3; the dissolved oxygen content of the pond water is around 6mg / L; the ammonia nitrogen content is less than 0.2mg / L; the hydrogen sulfide content is less than 0.002mg / L; the nitrite content is less than 0.01mg / L; the phosphate content is less than 0.05mg / L, the total nitrogen content is less than 25.0mg / L; and the total phosphorus content is less than 1.0mg / L.

[0051] The method to adjust the water quality is: when the pH is less than 7.5, spray 15 kg / mu of quicklime throughout the pond; when the pH is greater than 8.5, spray 500 mL / mu of acetic acid throughout the pond; when the ammonia nitrogen content is greater than 0.4 mg / L, apply 15 kg / mu of zeolite powder in the morning on a sunny day, and spray 3 L / mu of photosynthetic bacteria two hours later; when the nitrite content is greater than 0.03 mg / L, first use 1500 g / mu of nitrite antidote diluted with water and then spray the whole pond, and then directly spray 1 kg / mu of fast-acting oxygenator; when the hydrogen sulfide content is greater than 0.003 mg / L, use an oxidant to oxidize hydrogen sulfide into sulfate; when the dissolved oxygen is less than 4 mg / L, spray the oxygenator calcium peroxide throughout the pond.

[0052] Chlorella, Chaetoceros algae, Nitzschia closterium and EM bacteria were added to the experimental ponds for water fertilization. The EM bacteria were fermented and sprayed. 500g of EM bacteria were mixed with 1000g of brown sugar and 50 catties of sterile and non-toxic water for 2-3 days before use. 3-4 catties of fermentation liquid was used per mu of water. Microalgae were added to the pond at a concentration of 10% and sprayed at a water depth of 2 liters / mu·m. The control ponds were not sprayed with probiotics.

[0053] July-December: Economic species are released, including: Stage II seedlings of mud crab, seedlings of whiteleg shrimp, oyster, Gracilaria tenuifolia and yellowfin seabream.

[0054] The experimental ponds were stocked with mud crabs, whiteleg shrimp, Omi oysters, Gracilaria tenuifolia and yellowfin seabream. The stocking specifications, density, feed types and feeding amounts of economic species were as follows: the stocking specifications of mud crabs were crab stage II seedlings, with a density of 660 per mu; the stocking specifications of whiteleg shrimps were 1.05 cm / piece, with a density of about 10,000 per mu; large-sized individuals of Omi oysters were stocked for fattening, with a density of 82.5 kg / mu; and the cultivation density of Gracilaria tenuifolia was 10 kg / mu. At the end of July, mud crab stage II seedlings were released, and at the beginning of August, whiteleg shrimp seedlings were released. At the end of October, large-sized Omi oysters were released for cage culture and fattening, and Gracilaria tenuifolia was released in November for algae culture. The commercial shrimp and crab feed was fed throughout the culture process, supplemented with red meat basket clams, and Chlorella and diatoms (Chaetoceros and Nitzschia crescentica) were sprinkled from time to time. Yellowfin bream were released at an average of 20-30 per mu to prey on sick and slow-moving shrimps to prevent infection between infected individuals. The control ponds were the same as the experimental ponds in terms of stocking specifications, density, feed type and feeding amount of economic species, except that Gracilaria tenuifolia and probiotics were not released.

[0055] After the phased stocking of economic varieties is completed, the breeding management work and the nutritional quality testing of the breeding varieties are carried out, including: feeding of commercial shrimp and crab feed and observation of the feeding situation of shrimp and crab. Blue crabs and shrimps have the habit of hiding during the day and coming out at night, so the feeding should be reduced during the day and more should be fed at night. The specific feeding amount should be dynamically adjusted according to the growth and feeding of shrimps and crabs. 20-50 crabs and 20-50 shrimps are randomly caught from the control group pond and the experimental group pond, and the weight of shrimps and crabs and the body length of shrimps are measured, and the average value is calculated. When the average weight of blue crabs is below 15g and the average body length of shrimps is 1-6cm (weight is about 3g), the daily feeding frequency is twice, and when the average weight of blue crabs is greater than 15g and the average body length of shrimps is more than 6cm, the daily feeding frequency is three times. It is also necessary to master certain rules when feeding, and strictly follow the "three fixed" principles of timing, quantity and positioning for feeding. The time for feeding twice a day is around 7 o'clock and 16 o'clock, and the time for feeding three times a day is around 7 o'clock, around 15 o'clock and around 20 o'clock; the amount of feed fed is based on the average body length and average weight of the shrimp to estimate the total weight of the shrimp in the pond. When the average body length is 1-3cm, the daily feeding amount is 7%-10% of the total body weight, when the average body length is 3-6cm, the feeding amount is 5%-7%, when the average body length is 6-9cm, the feeding amount is 3%-5%, and when it is above 9cm, the feeding amount is 3%; in addition, red meat basket clams are used as bait to supplement the blue crabs to promote better and faster growth, at 3-5 kg / mu, in the afternoon or at night; when feeding, use the float valve to feed along the perimeter of the pond, which is the main place for shrimps and crabs to forage and live.

[0056] Randomly sample the farmed species, measure their health status, pathogens, and nutritional quality in the laboratory, and compare them with the individuals in the control pond to draw conclusions. During routine inspections, remove harmful debris in the pond water in a timely manner, pay attention to weather changes, water color, shrimp and crab eating conditions, etc., so that timely measures can be taken. Once shrimp, crabs, and fish are found to show symptoms, they will be caught in time, the symptoms will be identified and symptomatic treatment will be given in time to avoid large-scale disease outbreaks.

[0057] Water quality testing: water quality is tested regularly every other week. The schematic diagram of water temperature, salinity, pH, dissolved oxygen, ammonia nitrogen, hydrogen sulfide, nitrite, phosphate, total nitrogen and total phosphorus content in the experimental pond and the control pond over time is shown in the following figure. Figures 3 to 12 As shown, it can be seen that the water quality of the experimental pond is more stable than that of the control pond. Therefore, the water quality regulation strategy of the aquaculture method of the present invention can keep the aquaculture water quality stable.

[0058] The average body length of white shrimp in the experimental pond was 12.88cm / piece, and the average weight was 17.34g / piece; the average carapace width of mud crab was 93.14mm / piece, the average carapace length was 61.76mm / piece, and the average weight was 149.89g / piece; the average weight of Omi oyster was 231.9g, the average shell length was 93.7mm, and the average shell width was 63.8mm; the average body length of white shrimp in the control pond was 12.51cm / piece, and the average weight was 15.65g / piece; the average carapace width of mud crab was 81.40mm / piece, the average carapace length was 54.75mm / piece, and the average weight was 105.77g / piece; the average weight of Omi oyster was 213.4g, the average shell length was 92.9mm, and the average shell width was 62.4mm. It can be seen that the growth performance of the main economic species in the constructed multi-trophic level aquaculture is better. According to the production evaluation, the production of whiteleg shrimp in the experimental pond was 130kg / mu, the production of mud crab was 40kg / mu, and the production of Omi oyster was about 144kg / mu; the total production of whiteleg shrimp in the control pond was 100kg / mu, the total production of mud crab was 17kg / mu, and the total production of Omi oyster was 116kg / mu.

[0059] It can be seen from the above embodiments that the aquaculture method of the present invention can effectively ensure the water quality of the pond, and various economic varieties have fewer diseases, and no antibiotics are used throughout the process. In the entire pond, a small amount of yellowfin seabream moves in the upper water layer, preying on diseased shrimps and reducing the spread of diseases; white shrimp and mud crab live in the middle and lower layers of the pond and feed on feed; Omi oysters use microalgae as bait and can also filter impurities in the water; Gracilaria can absorb nitrogen and phosphorus in the water, and can also produce oxygen through its own physiological activities for other organisms to breathe. The entire pond conforms to the ecological concept, reduces the generation of harmful waste, and increases the economic benefits of farmers. The present invention provides a demonstration for establishing a multi-trophic level aquaculture model in brackish water ponds, and promotes the development of aquaculture.

[0060] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A multi-trophic level aquaculture model suitable for brackish water ponds, characterized in that: The process includes: 1) Preparation of aquaculture ponds, including dredging, disinfection, building aquaculture rafts, filling water, and adding biofertilizers and probiotics to fertilize the water; 2) Test the water quality of aquaculture water, including water temperature, salinity, pH, dissolved oxygen, ammonia nitrogen, hydrogen sulfide, nitrite, phosphate, total nitrogen and total phosphorus, and adjust the water quality to the following range: water temperature maintained between 20-30℃; salinity maintained between 8-15‰; pH value between 7.5-8.3; dissolved oxygen content higher than 5mg / L; ammonia nitrogen content lower than 0.3mg / L; hydrogen sulfide content lower than 0.002mg / L; nitrite content lower than 0.02mg / L; phosphate content lower than 0.05mg / L; total nitrogen content lower than 40.0mg / L; total phosphorus content lower than 2.0mg / L; 3) Establish a multi-trophic level aquaculture model, and stock economic species suitable for brackish water in phases and batches, including mud crabs, white shrimp, oysters and Gracilaria tenuifolia; 4) Stock the pond with yellowfin seabream; 5) Carry out breeding management, nutritional quality testing, and quality analysis of breeding products.

2. The breeding model according to claim 1, characterized in that: Step 1) The preparation of the breeding pond also includes pond cleaning and repair. The repair includes reinforcing and raising the pond, compacting the bank to avoid bank collapse and soil erosion; setting up water inlets and outlets; setting up fences around the pond; the desilting is to drain the pond water in winter or spring and remove the silt more than 10 cm on the surface of the pond bottom.

3. The breeding model according to claim 1, characterized in that: The disinfection method of step 1) is to freeze the pond for 1-3 months, and then use 80-100 kg (per mu) of quicklime 30 days before seedling planting, add water to make a slurry, and then sprinkle it all over the pond while it is hot, and then evenly plow the bottom mud to kill pathogens and improve the bottom quality.

4. The breeding model according to claim 1, characterized in that: Step 1) The biological fertilizer also includes phosphate fertilizer, potash fertilizer, urea, molasses and amino acid preparations, etc. The mixed biological fertilizer is added to the pond every 20-25 days to promote the growth and reproduction of microalgae.

5. The breeding model according to claim 1, characterized in that: Step 1) The probiotics are Chlorella, Chaetoceros algae, Nitzschia closterium and EM bacteria; the probiotics are added in the following manner: EM bacteria are fermented and sprayed, and 500g EM bacterial agent is used in combination with 1000g brown sugar and 50 jin of sterile and non-toxic water for fermentation for 2-3 days before use, and 3-4 jin of fermentation liquid is used per mu of pond in summer; a mixed algae liquid with a mass concentration of 10% is added to the pond, and the mixed algae liquid includes Chlorella and Chaetoceros algae, and is sprayed at a water depth of 2 liters / mu·m; in autumn and winter, Nitzschia closterium algae liquid is sprayed at a density of 10 million / mL, and is sprayed at a density of 4 liters / mu·m, and a fertilizer water preparation is sprayed at 4 kg / mu for the cultivation of algae in the water body. The probiotics are used once every two weeks to adjust the transparency of the water body, stabilize the water quality and water color, and avoid the phenomenon of thin water color and the growth of moss and mud.

6. The breeding model according to claim 1, characterized in that: In step 3), the culture method of economic species is as follows: Gracilaria tenuifolia is cultured by seine net and rope method, and is cultured separately from Crassostrea gigas.

7. The breeding model according to claim 1, characterized in that: Step 3) The specifications, density, feed types and feeding amount of economic species are as follows: the stocking specification of whiteleg shrimp is about 1.0 cm / tail, and the density is about 10,000 / mu; the stocking specification of mud crab is crab II seedlings, and the density is 500-800 / mu; large-sized individuals of Omi oysters are stocked for fattening, and the density is 70-100 kg / mu; the breeding density of Gracilaria tenuifolia is about 30 kg / mu, and the main feeding during the breeding process is commercial shrimp and crab feed, supplemented with a small amount of red meat basket clams, and chlorella and diatoms (horn algae and crescent algae) are sprinkled from time to time. Shrimp and crab feed is fed according to 3-10% of the body weight of shrimp and crab, and sampling and weight measurement are regularly conducted to track growth and feeding conditions, and the feeding amount is adjusted. Water samples are regularly drawn for testing, and the water color and algae phase of the water body are observed. Chlorella and diatoms and fertilizer preparations are appropriately supplemented.

8. The breeding model according to claim 1, characterized in that: In step 3), the order of stocking economic species is as follows: first, blue crab seedlings and white shrimp seedlings are stocked, one month later, Omi oysters are stocked, and yellowfin sea bream is stocked after another half a month, and fine-based Gracilaria is released according to water quality conditions.

9. The breeding model according to claim 1, characterized in that: In step 4), 20 to 30 yellowfin seabream are cultured per acre.

10. The aquaculture model according to claim 1, wherein the method for regulating water quality in step 2) is: when pH is less than 7.5, 15 kg / mu of quicklime is sprayed throughout the pond; when pH is greater than 8.5, 500 mL / mu of acetic acid is sprayed throughout the pond; when ammonia nitrogen content is greater than 0.4 mg / L, 15 kg / mu of zeolite powder is applied in the morning on a sunny day, and 3 L / mu of photosynthetic bacteria is sprayed after 1-3 hours; when nitrite content is greater than 0.03 mg / L, 1500 g / mu of nitrite antidote is first used, diluted with water and sprayed throughout the pond, and then 1 kg / mu of quick-acting oxygenator is directly sprayed; when hydrogen sulfide content is greater than 0.003 mg / L, hydrogen sulfide is oxidized into sulfate with an oxidant; when dissolved oxygen is less than 4 mg / L, oxygenator calcium peroxide is sprayed throughout the pond.

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