Development Status and Trends of Industrial Recirculating Aquaculture System in Haiyan County
In recent years, with the implementation of cultivated land protection policies and the formulation of aquaculture waters and beach planning in Haiyan County, the aquaculture area in Haiyan County has been gradually decreasing. According to the spirit of documents such as the "Several Opinions on Accelerating the Green Development of Aquaculture" jointly issued by the Ministry of Agriculture and Rural Affairs and nine other ministries and commissions, ecologically healthy aquaculture models have become the focus of future fishery development. Industrial aquaculture, which aligns with the characteristics of intensive, large-scale, and modern aquaculture, represents an important direction for the county's future aquaculture development.
I. Development History and Current Status of Industrial Recirculating Aquaculture in Haiyan County
The industrial aquaculture in Haiyan County can be divided into two stages.
1. Industrial Greenhouse Aquaculture of Soft-Shelled Turtle
Chinese soft-shelled turtle, as one of the three major aquaculture species in the county, was primarily cultivated using a two-stage method combining greenhouses and ponds before 2020. Juvenile turtles were raised in greenhouses, while most sub-adult to adult turtles were raised in ponds (including pond mud bottom culture and cement pond intensive culture), with a small portion using ecological polyculture (shrimp-turtle polyculture, turtle-shrimp-fish polyculture, fish-turtle polyculture, and rice field turtle culture). In 2020, the total area of industrial greenhouses in the county was 526,000 m², with turtle production and output value accounting for 45% and 54% of the county's total fishery, respectively. Greenhouse turtle farming in Haiyan County has contributed to the development of the agricultural industry and the increase of farmers' income over the years. However, it also faced practical problems such as traditional and extensive industrial structure, poor product competitiveness, and aquaculture environmental pollution, resulting in low development quality. From 2020 to 2021, all industrial greenhouses in the county were completely dismantled, and comprehensive aquaculture tailwater treatment was promoted throughout the region.
2. Industrial Recirculating Aquaculture
Currently, the county has built 10 industrial recirculating aquaculture facilities with complete water treatment systems. Based on output, they can be divided into two types: commercial fish farming (6 facilities) with an annual output of 200 tons of aquatic products; and seedling cultivation (5 facilities) with an annual output of 1.5 billion shrimp fry. Among them, Zhejiang Jinyu Biotechnology Co., Ltd., as a large-scale high-quality seedling breeding base in Zhejiang Province, is carrying out a digital technology upgrading project for fish and shrimp seedling breeding to enhance the intelligent level of seedling production. The Australian Silver Perch Seedling Breeding and Production Demonstration Base features Australian silver perch broodstock breeding and cultivation. Jiaxing Fuju Agricultural Development Co., Ltd., as a leading entity in Zhejiang Province's agricultural "dual strength" initiative, is creating a whole industry chain development model covering blue shrimp breeding, cultivation, and processing.
II. Existing Problems
1. High Equipment Investment and Operating Costs
The industrial recirculating aquaculture system requires significant capital investment in the early stage for basic infrastructure construction, including land, factory buildings, recirculating system infrastructure, and installation of complete equipment and facilities. In actual operation, seedling costs, electricity, feed, management, and other aspects also require substantial financial support, deterring smaller-scale farmers. This high entry barrier increases the difficulty of promoting the recirculating aquaculture model.
2. Overall Production Level Needs Improvement
Currently, industrial aquaculture can be roughly divided into three forms: flow-through aquaculture, semi-closed recirculating aquaculture, and fully closed recirculating aquaculture. Due to pressure from water treatment costs, Haiyan County mainly adopts semi-closed recirculating aquaculture. During the cultivation period, the entire water body circulates and flows. After one cultivation cycle, the water is discharged into outdoor "three-pond, two-dam" tailwater treatment ponds. After meeting standards, the water is either discharged or recirculated. Some industrial facilities have fewer equipment installations, relying more on manual operation during production, resulting in lower production efficiency.
3. Insufficient Knowledge and Management Experience in Recirculating Aquaculture
Most industrial recirculating aquaculture operators in Haiyan County have not received professional training. They explore and summarize through production practice, lacking experience in cultivation cost and risk management, making it difficult to achieve optimal profitability. Taking Qinshan Lvzhiguo Family Farm in Haiyan County as an example, they adopted industrial recirculating aquaculture for grouper. In 2021, due to improper operation by management personnel, 2 tons of grouper that had reached commercial size died from hypoxia, resulting in significant losses.
III. Current Work Ideas and Countermeasure Suggestions
1. Integrate Multiple Resources and Strengthen Policy Support
First, provide policy resources. Based on the actual situation in Haiyan County, the role of economic leverage can be fully utilized by combining industrial recirculating aquaculture facility construction with government agricultural infrastructure transformation and agricultural technology extension, thereby reducing the burden on industrial recirculating aquaculture enterprises. Second, build platform resources. Based on industrial layout and development orientation, introduce high-quality industrial recirculating aquaculture enterprises, seedling production enterprises, and excellent talent to enhance the hard and soft power of modern fishery development in Haiyan County.
2. Enhance Capabilities Through Multiple Channels and Strengthen Research and Demonstration
First, research-driven approach. Based on the industrial aquaculture conditions in Haiyan County, hire university experts and invite experienced practitioners in industrial recirculating aquaculture as technical consultants, and organize targeted training sessions to continuously improve the professional level of operators. Second, technology-driven approach. Actively encourage industrial recirculating aquaculture operators to accelerate technological updates through project applications, establish an industrial recirculating aquaculture industry association in Haiyan County, strengthen technical exchanges, and form collective synergy to enhance overall industrial level and strength. Third, improved variety-driven approach. Introduce varieties suitable for industrial aquaculture, organize study tours to Shandong, Liaoning, Guangdong, and other regions, and invite typical industrial recirculating aquaculture operators from outside the province to exchange in Haiyan County, enriching the varieties for industrial aquaculture and improving farming efficiency.
3. Establish Supporting Systems and Leverage the Advantages of Industrial Aquaculture
Most industrial aquaculture facilities in Haiyan County have low automation levels, with many operations still completed manually. On one hand, advanced domestic and international equipment and facilities can be introduced, and local aquaculture recirculating water enterprises can be encouraged to update their technology and equipment, such as adopting automatic feeders, automatic harvesters, automatic wastewater treatment devices, etc., to enhance industrial level and risk resistance capacity. On the other hand, accelerate technological innovation, cooperate with research institutions and universities, and accelerate research on equipment, facilities, and technologies suitable for local industrial aquaculture, reducing production operation and initial investment costs.
3. Establish Supporting Systems and Leverage the Advantages of Industrial Aquaculture
Most industrial aquaculture facilities in Haiyan County have low automation levels, with many operations still completed manually. On one hand, advanced domestic and international equipment and facilities can be introduced, and local aquaculture recirculating water enterprises can be encouraged to update their technology and equipment, such as adopting automatic feeders, automatic harvesters, automatic wastewater treatment devices, etc., to enhance industrial level and risk resistance capacity. On the other hand, accelerate technological innovation, cooperate with research institutions and universities, and accelerate research on equipment, facilities, and technologies suitable for local industrial aquaculture, reducing production operation and initial investment costs.
4. Strengthen Healthy Aquaculture Management and Follow the Path of Green Development
First, wastewater discharge supervision. Include industrial recirculating aquaculture operators within the management scope. Currently, industrial recirculating aquaculture in Haiyan County is semi-closed. After each cultivation cycle, the aquaculture tailwater needs to be treated before discharge or recirculation. Strengthen supervision to prevent direct discharge. Second, aquatic product quality and safety supervision. Industrial aquaculture is a closed aquatic ecosystem, and disease prevention and control require particular attention. Strengthen aquatic product quality supervision to prevent product drug residue issues from affecting the development of the entire industry.