Restocking technology of fish species after rainstorm

Every year, some areas are hit by typhoons and torrential rains, resulting in the collapse of the ridges of fish ponds and serious escape from fish. After the rainy season, timely restocking of fish species will reduce the loss caused by the flood to a minimum. The restocking techniques of fish species after heavy rain are introduced as follows.

1. The source of fish species

After the rainstorm, if the weather is hot and it is inconvenient for fish to be transported over a long distance, it is generally solved by local adjustment, or you can fish in the natural water body nearby. The fish caught are released nearby and should not be kept away from the water for too long. All operations should be carried out in the cage or pull the net, but the time had better not exceed 2 hours, it is strictly forbidden to leave the water.

2. Preparation before stocking

(1) to renovate the dike ridges washed out by the flood and block the open water body, the important sections of the dangerous ridges must be strengthened and compacted with new soil to prevent leakage and solve problems immediately; ensure that the dike cannot be broken again.

(2) to observe the situation of escaping fish in the pond in order to find out the bottom and determine the restocking species and stocking quantity.

(3) clarifying the turbid water after the disaster with quicklime, alum and other drugs to purify the water quality. If the water body is too thin, apply fertilizer slightly to improve the water quality.

3. Stocking

Healthy fish with intact scale fins, powerful jumping and active swimming should be selected for free-range fish. Fish that are thin, slow to respond, hyperemia on the body surface and mechanical damage should be removed. The variety of stocking can be determined according to the situation, the stocking specification requirements are much better, and the stocking density can be properly sparse, so that it can grow into commodity specifications at the end of the year. Before entering the pond, the fish were soaked with 2%-3% salt water or 1-22 mg / L crystal trichlorfon for 3-5 minutes to prevent the spread of bacteria.

4. Management

After fish fingerling is released, concentrate feed should be strengthened to ensure the rapid growth of fish fingerling. It is more appropriate to feed about 8% of the total weight of fish in the pond, with a slight surplus observed after feeding. If there are more silver carp and bighead carp, more fertilizers should be added. Fertilization should be based on the principle of a small amount of fertilizer for many times, organic fertilizer should be fully fermented and then applied into the water body, the amount of organic fertilizer should be 50kg / mu and 100kg / mu, and ammonium bicarbonate or urea water can be used to sprinkle the fertilizer evenly, and the amount of natural bait in the culture water is 5kg / mu or 3kg / mu respectively.