Ecological Farming Model of Fishing to Purify Water

 In the Yinglong Lake Reservoir in the Nan'an District, there was a drizzle of rain. The master boatman Wang Lixin and the person in charge of the reservoir Fan Wancheng drove the patrol boat to the center of the lake.

The lake is blown by the autumn wind, the blue waves are rippling, the fish jump out of the water from time to time, and the reflections of the trees on the lakeshore are interesting. Fan Wancheng couldn't help sighing at the scene in front of him: "Yinglong Lake Reservoir, which was once eutrophic, is not easy to reproduce the water and fish!"

Fan Wancheng said that in recent years, Yinglonghu Reservoir has achieved both economic and ecological benefits through the implementation of the ecological breeding model of "fishing with water and purifying water with fish".

The Yinglong Lake Reservoir was officially put into use in 2008, and has multiple functions such as agricultural irrigation water and drinking water for humans and animals. The total storage capacity of the reservoir is nearly 18 million cubic meters, which mainly provides production and domestic water for four towns and towns of Yinglong, Changsheng, Guangyang and Xiakou, as well as Chayuan New Town.

Fan Wancheng and Wang Lixin also took up the responsibility of protecting the ecological environment of the reservoir from then on.

At first, the water quality of the reservoir was relatively good, but two years later, a worrying problem occurred - the water body began to become eutrophic.

"Duckweed, blue-green algae, water hyacinth, etc. grew in large quantities in the water, and the water became turbid." Fan Wancheng recalled that because it was a drinking water source, chemical drugs could not be used to remove phytoplankton, and only manual salvage was required. It takes several tons of phytoplankton to fish every day, but the effect is not good, and the phytoplankton will grow back very quickly."

In 2011, Liangjiang Fisheries, a subsidiary of Chongqing Water Investment Group, promoted the ecological aquaculture model of "raising fish with water and purifying water with fish", and the water quality of Yinglong Lake Reservoir was improved.

The relevant person in charge of Liangjiang Fisheries said that the ecological breeding model of "fishing with water and purifying water with fish" is to put fish fry into the reservoir. Algae, water purification with fish and other functions.

"The silver carp and silver carp fry were cast in that year, and then a batch of adult fish was caught every year, and a batch of new fry was put in. The water quality of the reservoir gradually returned to its former clearness," said the person in charge. Reservoir ecological fish farming is different from other farming methods. No fertilization or medicine is used. It mainly breeds silver carp, silver carp and other fish that can purify water quality.

While taking into account ecological protection, the small reservoir "swim" out a large ecological fish industry. Today, the Yinglong Lake Reservoir's ecological aquaculture model of "raising fish with water and purifying water with fish" has been promoted in more than 70 reservoirs in the city, producing more than 5 million catties of fish every year and selling well in the city center of our city. At present, Liangjiang Fisheries is opening up the entire fishery industry chain of "Fanjiaqiao Seedling Farm - Yinglong Lake Large-Scale Fish Farm - Fish Reservoirs in Districts and Counties - Four Area Transit Bases - Featured Processing Plants - Brand Marketing Network - Dining Tables". Brighten the brand of "Yuhu Reservoir Fish".

"Next, we will plant more aquatic plants on the water surface of Yinglong Lake Reservoir to absorb harmful substances in the water, provide an original ecological growth environment for fish, and make the ecosystem of the reservoir more diversified and three-dimensional, which not only purifies the water, but also Improve the quality of fish." said the relevant person in charge of Liangjiang Fisheries.

Can fish farming no longer use antibiotics

 At present, aquaculture relies heavily on the use of antibiotics, however, the residues of antibiotics in farmed products and the natural environment have caused serious microbial resistance problems worldwide, including China, the European Union, the United States and the United Kingdom. And the Community has successively introduced policies to reduce or even ban the use of antibiotics in feed. Therefore, there is an urgent need to develop new antibacterial, biosafe, environmentally friendly and biodegradable new antibacterial agents for aquaculture that can replace antibiotics.

Recently, the research group of Professor Liu Runhui from East China University of Science and Technology has made a breakthrough in the research on the replacement of antibiotics for aquaculture, and discovered a biodegradable polypeptide polymer, which has high-efficiency broad-spectrum antibacterial activity and good biocompatibility. The preferred polypeptide polymers not only exhibited significant therapeutic effects in the zebrafish in vivo infection model, but also showed no bacterial resistance to continuous use. At the same time, the antibacterial polypeptide polymers found in this study can be degraded into single amino acids and dipeptides that completely lose antibacterial activity under the action of enzymes, which effectively avoids the problem of antibacterial resistance caused by antibiotic residues in the environment. Perfect unification of high antimicrobial activity, biosafety and environmental friendliness for antimicrobial agents.

Based on the NCA rapid ring-opening polymerization method established by Professor Liu Runhui's research group in the early stage, this study synthesized polypeptide polymers composed of different proportions of lysine and serine, and selected the most common ones in aquaculture through high-throughput screening methods. Antibacterial polypeptide polymers with broad-spectrum antibacterial activity against pathogenic bacteria while maintaining low hemolytic activity and low cytotoxicity.

Compared with commonly used antibiotics, polypeptide polymers show faster bactericidal speed, and long-term use will not induce bacterial resistance and cross-resistance. Compared with most non-degradable antibiotics or other antibacterial agents that still retain antibacterial activity after degradation, the enzymatic degradation products of biodegradable polypeptide polymers completely lose antibacterial activity, which can effectively reduce the residues of antibacterial substances in the environment and the corresponding selection. Sexual antibacterial stress.

The study also established a zebrafish infection model to further study the in vivo antibacterial activity of the polypeptide polymers. After intraperitoneal injection of the preferred polypeptide polymer, the survival rate of zebrafish infected with Vibrio eel could be increased to 88%, and the bacterial load in the liver, spleen and kidney was significantly reduced, and there was no evidence of Vibrio eel infection. Bleeding symptoms. In addition, intraperitoneal injection of the preferred polypeptide polymer did not cause abnormal serum biochemical indexes in zebrafish, showing good in vivo safety. This study shows that the preferred biodegradable polypeptide polymer is expected to be used as a substitute for antibiotics in aquaculture, and can be extended to other antibiotics in aquaculture, with potentially important application value.

With the rapid development of the world's population and economy, the breeding industry has also entered a stage of modernization, intensification and large-scale development. In order to meet the production needs of high quality and high yield, antibiotics are widely used in aquaculture. In 2013, the global consumption of antimicrobials (mainly antibiotics) in the aquaculture industry was approximately 131,000 tons and is expected to exceed 200,000 tons by 2030. The massive use of antibiotics has caused serious drug resistance problems worldwide. On the one hand, residual antibiotics in farmed animals will be passed to humans through the food chain, further destroying the microbiota in humans and inducing bacteria to develop drug resistance. On the other hand, most of the antibiotics used in aquaculture, especially aquaculture, will remain in the environment. At present, antibiotics that are not easily degradable, such as sulfonamide, have been detected in surface waters of various countries with high concentrations of residues, which has caused huge selective antibacterial pressure on the environment.

Faced with the severe challenge of microbial resistance, many countries have successively introduced policies to reduce or even ban the use of antibiotics in feed. Document No. 194 of the Ministry of Agriculture and Rural Affairs of China also announced that China will usher in a comprehensive ban on the feed side from 2020. The age of antibiotics. Therefore, research on the replacement of antibiotics in aquaculture is imminent.

Rice and Fish Symbiosis Industry Boom in Jingxi, Guangxi China

In recent years, Diding Village, Nanpo Township, Jingxi City has insisted on taking industrial development as an important starting point for promoting rural revitalization. Through measures such as leading the party flag, improving supporting facilities, cultivating brands, and extending the chain, it has vigorously developed the comprehensive rice and fishery planting and breeding industry, and has stepped out of the It has developed a characteristic industry development path that enriches the people and strengthens the county and rural revitalization.

Leading by example, breaking the bottleneck of fish farming development.

Diding Village is adjacent to the Guangxi Diding Autonomous Region-level Nature Reserve. It is rich in water resources. It has always been the habit of raising fish in rice fields. It has a history of more than 200 years using rice fields to raise fish, but it has not yet formed a scale. In order to break the bottleneck of small scale and weak strength of fish farming in rice fields, the village Party branch adopted the measures of "double introduction and double belts", and through the development model of "branch + cooperative + base + farmer", it created the kind of farming in Jingxi Tongdong. Professional cooperatives, actively cultivate capable people, guide party members, big farmers and capable people to join the cooperatives, lead farmers to develop in "groups", and drive the masses to develop the rice field fish farming industry. At present, the village has built a 600-mu demonstration base for maintaining grain, stabilizing fisheries, and increasing income. Through demonstration and establishment, it promotes the radiation and promotion of the periphery, and drives the surrounding villagers to develop an area of ​​more than 3,000 mu of comprehensive rice and fish farming.

Improve supporting facilities, "two bases" promote fish industries from inferior to superior

Due to the lack of industrial facilities and development elements, it is difficult for the rice field fish farming industry to show competitive advantages in terms of output and quality. In addition, the lack of awareness and technical specifications for the protection of germplasm resources has made black carp more and more hybrid, resulting in a damaged market image. , the economic benefits continue to decline. Diding Village took the initiative to seize the opportunity of linking rural revitalization, Guangdong, Guangxi, eastern and western cooperation to help each other, and strived for project funds to create the Jingxi Black Carp Purification and Rejuvenation Breeding Base and Diding Village Rice and Fishing Ecological Comprehensive Breeding A demonstration base for raising water, 4.5 kilometers of new water conservancy channels, and 8,000 meters of hardened ridges.

With the increasing investment in industrial supporting facilities, black carp has slowly recovered from the endangered population to a certain population size. The breeding base can provide more than 1 million fish fry every year, and provide about 3,000 mu of farms in various towns and towns in Jingxi, and about 500 farmers. The integrated rice-fishing cultivation basically meets the local demand for high-quality fry. In addition, the output of the demonstration base has increased from 800 jin of rice and 40 jin of fish per mu to 1,200 jin of rice and 80-100 jin of fish per mu. "One water for two purposes, one field for more harvests, stable grains and increased efficiency, and a win-win situation for grain and fishery", and the production and income of rice and fishery have been increased year by year for three consecutive years.

Brand cultivation and cultural empowerment enhance industrial value.

In order to enhance the brand competitiveness of comprehensive fish farming in paddy fields, build a brand of green and high-quality agricultural products, and transform brand advantages into product advantages, market advantages, and price advantages, Diding Village successfully registered the "Xuanbo Fish" trademark in 2021, marking the "Xuanbo Fish" trademark. Fish" has been officially protected by national laws since then. At the same time, it is actively applying for the certification of organic agricultural products and assisting Jingxi Agriculture and Rural Bureau in applying for geographical indication agricultural products. Jingxi black carp has also been recognized as "China's Important Agricultural Cultural Heritage" by the Ministry of Agriculture and Rural Affairs of the People's Republic of China, which enables the inheritance and protection of Jingxi black carp farming culture, and further enhances the brand's influence and driving force.

Extend the chain and promote the upgrading and upgrading of characteristic industries.

Diding Village adheres to the demonstration first, and creates a demonstration piece of comprehensive planting and breeding of collective economic paddy fields in Diding Village by transferring 500 mu of land. The way of self-cultivation and self-cultivation by farmers and centralized purchase and sales of cooperatives increases farmers' income on the basis of ensuring food supply and output. . At the same time, relying on the Fengji fruit primary processing base and freezer which are under construction, the agricultural products produced by the demonstration films will be sorted, packaged, stored, transported and sold to initially form an upstream industrial chain and increase the village's collective economic income. In addition, the comprehensive planting and breeding of paddy fields can also place labor force nearby for employment, successfully driving 600 people in Diding Village, and radiating 2,000 people in the township to achieve employment at their doorsteps, driving the income of farmers to increase.

Intelligent Fish Farming Breaks a New Road to Wealth

 The maximum outdoor temperature is nearly 40°C, but the temperature is comfortable in the rows of large breeding workshops in Wugang Village, Gaozi Street, Dantu District, without the slightest feeling of heat and dryness. On August 10, the reporter came to Zhenjiang Xinrun Agricultural Development Co., Ltd. In a large workshop of more than 800 square meters, there are several giant breeding ponds, and the water temperature is adjusted according to the species and age of the fish. There are more than 10 such aquaculture workshops, which can produce more than 100,000 catties of high-grade finished fish each year, which is in short supply in the market.

The chairman of the company, Xie Xudong, was the first "Top Ten Farmers" in Dantu District. He was obsessed with science and technology, and after many ups and downs, he finally made a major breakthrough in the technology of factory-based "smart farming". On the well-off road.

Chasing dreams and forming an indissoluble bond with "fishing"

Xie Xudong, 40 years old this year, looks relatively white, mainly due to the result of long-term indoor breeding. He told reporters that he had a strong interest in farming since he was a child, and when he went to middle school, he became more and more interested in fish farming. On the eve of the college entrance examination, his first choice was to apply for the biotechnology major of Jiangsu Ocean University, and the result came true. His first job after graduation was related to fishing, which was a dream come true for him.

In 2005, Xie Xudong entered a well-known domestic company in Wuxi at that time, engaged in the sales of aquatic additives, which benefited him a lot. He further learned from his work that different fish have great differences in water quality, temperature, climate, and disease resistance. This opens a whole new window for Xie Xudong. He could never learn such professional knowledge in university, which is a huge wealth.

"In those years, I collected and sorted out a lot of technical information on fish farming, and made a lot of notes." Xie Xudong said that due to the needs of his work, he traveled south and north, established contacts with many domestic farmers, and deeply realized the hardships of aquaculture. And risks, some farmers will cause hundreds of thousands or millions of losses due to a small negligence. To this end, he always shared his experience with farmers for free, which was widely praised and played a good exemplary role.

After accumulating several years of work experience, in 2013, Xie Xudong gave up the high salary of more than 400,000 yuan per year from his original unit and returned to his hometown Dantu to start his own business. Compared with other aquaculture farmers in the village, he does not dig ponds first, but builds large workshops. Xie Xudong said that only factory-based intelligent farming and the use of scientific and technological means can change the outdated pattern of "depending on the sky", and the aquaculture industry can walk out of the road of innovation and usher in new opportunities.

Scientifically farming shad finally succeed

"Only a high starting point can open up a new market pattern and obtain high benefits." Xie Xudong said, with the continuous development of agricultural modernization, the development momentum of scientific and technological breeding has been rapid in recent years, and the factory-based breeding model has become more and more advantageous, but this This model has higher investment, higher risk, and longer return period. Seeing that the breeding workshop has cost more than 10 million yuan and is still unfinished, many villagers are sweating for Xie Xudong, but at this time Xie Xudong has already There is no way out.

American shad cultivated by Xie Xudong

As a native of Zhenjiang, he has unique memories and feelings for shad, saury, and puffer fish, which are the "three fresh products of the Yangtze River". In recent years, the Yangtze shad has almost disappeared from the public eye. Xie Xudong learned by chance that there is an American shad in North America with similar climatic conditions to Zhenjiang, which is similar to domestic shad in both appearance and meat quality, and has been successfully introduced and cultivated.

It is precisely because of the American shad farming that Xie Xudong spent a lot of money to build a factory-like intelligent farming greenhouse workshop. He traveled thousands of miles to the origin of the American shad, went deep into the spawning area, and actively introduced wild populations. In conjunction with the Freshwater Fisheries Research Center of the Chinese Academy of Fishery Sciences, the Jiangsu Fishery Technology Promotion Center and other scientific research units, a special project has been established to overcome the difficulties in the selection and breeding of American shad. At present, his company has become the enterprise with the most abundant species of American shad parentage in Jiangsu, and it is also one of the few enterprises in China that has successfully mastered the full artificial breeding of American shad.

Xie Xudong told reporters that each pond in the breeding workshop has a capacity of more than 500 cubic meters, and the temperature, humidity, oxygen content, feed ratio, nutrition regulation, disease prevention and control and many other aspects have intelligent processing modes, and the breeding environment is not weak. Due to the natural environment and the delicious meat of the fish, it is widely welcomed by high-end hotels. At present, merchants from all over the province and from Shanghai, Zhejiang, Anhui and other places are coming, and the supply of shad is in short supply. This year alone, the company has bred more than 1 million shad fry, cultivated more than 100,000 catties of adult fish, established a company and farmers with an area of ​​more than 500 mu for promotion and demonstration, with a total output value of more than 50 million yuan.

Bass Farming leads the villagers to get rich

The success of American shad farming has also made Xie Xudong "fire" and has become a well-known technology breeding expert, but for Xie Xudong, he still feels a little lost. Except for a few farmers who are willing to breed American shad, most People shy away from it. The main reason is that American shad farming is a high-cost and high-return project, which is difficult for ordinary farmers to bear. In order to help more villagers get rich, Xie Xudong did not stop, and after American shad farming got on the right track, he focused his attention on the species of California bass.

California sea bass, scientific name largemouth bass, is native to the Americas and has been introduced to China for decades. In recent years, with the breakthrough of artificial breeding technology and artificial compound feed domestication technology, the breeding area has increased significantly, the cost has also been reduced a lot, and the market benefits are good. However, due to the lack of large-scale nursery bases in Zhenjiang, farmers can only buy fry from Zhejiang, Guangdong and other places, but they are often deceived because they do not understand the situation.

Xie Xudong took advantage of his professionalism and the facilities of the company to buy better California perch from different regions for breeding. Through comparison, he concluded a reliable source of fry, and then cooperated with local farmers to purchase in a group. This not only ensures the quality of the fry, but also saves the cost of farmers. He also imparts technology free of charge, which drives the majority of farmers to embark on the road of prosperity. Xie Xudong often said that the future of the breeding industry is limitless, and with the care of the party and the government and the help of the scientific research team, it will surely usher in better development.

In recent years, Xie Xudong and his team have continuously increased investment in scientific and technological research and development, and have successively undertaken and participated in the Jiangsu Province Agricultural Machinery Three New Projects "Integrated Application of Mechanization Technology in Key Links of Healthy Shad Breeding", Zhenjiang City Science and Technology Plan Project "Yangtze-mouthed mandarin fish" 8 agricultural science and technology projects including "Integration and Application of Efficient Ecological Breeding Technology". This year, his company was recognized as "Jiangsu Provincial Advanced Breeding Farm" by Jiangsu Provincial Department of Agriculture and Rural Affairs, and was awarded the "Provincial Genetics Society Scientific and Technological Service" by Jiangsu Genetics Society. Station", and jointly established and listed the "Comprehensive Experimental Demonstration Base of Freshwater Fisheries Research Center" with the Chinese Academy of Fishery Sciences; accumulatively published 3 scientific papers in professional journals, and obtained 2 patents authorized by the state.