Salmon environmental protection breeding net cage in Xinjiang, China

The magical story of a herdsman becoming a fisherman----salmon farming in Xinjiang, China

(By Ellie Xinning Li, Shanghai, CHINA)

Recently, the Xinjiang Tianyun Organic Agriculture Company in Xinjiang, China, will have a bumper harvest of 6, 000 tons of salmon, which will be sold to various parts of China, Malaysia, Singapore and other places. The salmon are raised in glacier water and the eggs are from Denmark. The company is a complete digital fishery industry chain integrating scientific research and development, seed breeding, intelligent breeding, deep processing, and brand building. Many local herdsmen have switched to salmon farming.

How can such a high output be achieved here, so far from the sea? This is due to the unique natural conditions in the county of Neke, Xinjiang. Neke County is one of the three coldest areas in the Ili Prefecture. In summer, it is relatively rare to see it, because the Kashi River flowing around the Tianshan Mountains carries the meltwater from the glaciers all year round, keeping the water temperature below 10 ℃. This is perfect for cold-water fish such as salmon.

Salmon, scientific name for salmon, is the common name for several species of salmonids (such as Atlantic salmon and Pacific salmon). You may have heard of various wild or farmed salmon, but the most common commercially available is farmed Atlantic salmon.

Salmon farming began in the 1960s as an experimental endeavor, and gradually developed into an industry in Norway and Chile around the 1980s. The salmon farming industry has grown significantly over the past 40 years, and now approximately 80 % of the world's salmon production comes from aquaculture, with a production of approximately 2. 9 million tonnes of cultured Atlantic salmon (WFE) in 2021.

Atlantic salmon farming has traditionally been dominated by a few breeding regions such as Chile, Norway, Canada, and Scotland, as Atlantic salmon must typically meet several extremely stringent natural conditions in order to ensure the best cultured salmon.

Among them, water temperature is the most important factor limiting the geographical distribution of salmon. The maximum temperature for salmon to grow is around 4-25°C, with an optimal temperature of 8-14°C. The temperature range for hatching fish eggs is between 0 and 15 °C. If the temperature exceeds this range for a long time, the fish will die in large numbers, therefore the natural spawning grounds and breeding areas for Atlantic salmon are mostly located near the poles.

Salmon breeding and processing processes

The salmon aquaculture in Xinjiang can be dated back to 2014 when Song Yong, a professor of life sciences at Tarim University, led his students to start the research on artificial seawater aquaculture. There is no grass in the saline-alkali marshes, with the average annual temperature no higher than 7 degrees Celsius, so no crops can grow in such an environment. However, Song Yong, who had worked with cold water fish for many years, soon saw the potential of breeding salmon on this land.

After initial planning, Professor Song Yong began to fish in 250 acres of salt marsh at the Red Flag Farm, which is located in the eastern Pamir. After improving the water quality of the barren salt marsh, the farm began to raise salmon. After numerous trials and errors, it has finally produced artificial seawater suitable for different sea products to grow in and is able to breed 8 kinds of imported high-end sea fish popular among Chinese people, such as the South American shrimp and the tilapia, to simulate the marine environment to the greatest extent.

Today, a number of farming companies in Xinjiang have completed the development of saline-alkali land, such as Xinjiang Shishixian Aquatic Product Co., Ltd., whose farm covers an area of about 5, 000 acres. They make use of saline-alkali soil to mix water with microelements and probiotics to make artificial seawater suitable for different marine products. They use a hydrometer to measure the salinity and alkalinity of the water in the tank, and adjust the seawater according to the mineral composition of the seawater. They also simulate the ecological environment of seawater in the breeding tank for seafood breeding, providing a safe, reliable and controllable growth environment for seafood. The salinity standard of the fishpond water after debugging is close to that of real seawater. The improved artificial seawater, using the"4 + 1" technology, forms a small marine system that can cultivate eight varieties of "seafood" such as tilapia, grouper, white shrimp, abalone, and lobster.

In addition to artificial seawater technology, fishery equipment engineering technology is also the core technology of salmon farming. The semi-closed circulating water fish farming system solves the three common problems encountered in the process of cold-water fish breeding: first, the appetite decreases when the water temperature is high in summer; the second is that the dissolved oxygen content in the water affects the normal growth and development in winter. After the use of semi-closed circulating water fish farming system, the growth cycle of fish was shortened from 36 months to 26 months, the survival rate increased by 3%, the conversion rate of bait increased by 10%, the comprehensive profit margin increased by 10%, and the risk of extreme climate conditions to fishery production was effectively resolved. In short, the technical development of artificial seawater and fishery equipment engineering has important practical significance and prospect. In the future, the fishery equipment project will be low-carbon, intelligent, safe and sustainable, and continuously promote the upgrading and reform of the fishery industry.

(By Ellie Xinning Li, Shanghai, CHINA)