The structure of cold-water fish culture pond is rectangular, and the corners are blunt. It makes sense to swim without dead ends. Fish can be evenly distributed throughout the pond. The fish pond is 4 meters wide and the length is no more than 15 meters.

The fishpond sewage outlet is equipped with a fish fence and two gates, and inverted siphon drainage is adopted, which is beneficial to the discharge of bottom dirt. Water supply in fish ponds should be in parallel to reduce the chance of fish cross-infection.

The water supply conditions in fish ponds are not good. If series fish ponds are used for water supply, a sedimentation tank should be set below the drain to reduce the harm of metabolites such as residual bait fish manure to the fish in the pond below. Although the stocking density of cold-water fish can be increased with the increase of water exchange capacity and dissolved oxygen, the stocking density is above 16 kg/m3.

Extended data:

Cold-water fish has a history of more than 100 million years and is called "living fossil in water". China is one of the countries with the largest species, the widest distribution and the richest resources of cold-water fish.

Wild cold-water fish in China include ACIPENSER schrenckii in the middle reaches of Heilongjiang and the lower reaches of Songhua River, Dalbergia odorifera and ACIPENSER schrenckii in Yining, Suiding and Michal in Xinjiang, and ACIPENSER schrenckii in Siberia and Bosten Lake in Xinjiang.

However, due to the influence of three main factors, such as river damming, environmental pollution and overfishing, sturgeon resources are shrinking, and most existing species are in a critical state.