What preparations should be made for fish farming in winter? What is the impact on fish culture?

With the coming of winter, the temperature is getting lower and lower, and the water surface in some places will begin to freeze, which will have a certain impact on fish culture, so what preparations should be made for fish farming in winter? What is the impact on fish culture?

What is the impact of winter on fish culture?

The main results are as follows: 1. The time of light in winter is relatively short, the light intensity is relatively weak, and the water temperature is low, which has a great influence on the growth and reproduction of some algae. The water quality of fish ponds in winter will be turbid and thin, and the balance of algae and bacteria can be easily broken. Bacterial diseases are more likely to occur (bottom fish hemorrhage, etc.)

2. With the frequent invasion of cold air, strong convection is caused by the change of wind direction and rapid cooling of surface water, which is easy to cause water instability. The concentration of toxic and harmful substances such as ammonia nitrogen, salt and hydrogen sulfide is easy to exceed the standard, and the water temperature decreases rapidly and greatly. Great stress on fish

3. Winter belongs to the later stage of culture, and the accumulation of residual bait and feces at the bottom of the pond and the consumption of carbon source and phosphate fertilizer in the pond are not replenished in time, which affects the normal operation of the material circulation in the pond and reduces the overall productivity of the pond. it also makes ammonia nitrogen, salt and other harmful substances further accumulated.

4. Other aspects: there are too many fish stocks with unsatisfactory fish prices, resulting in a lack of oxygen and floating heads; too much or too little feeding may lead to waste or fat loss.

Second, what should we pay attention to when raising fish in winter?

1. Make a simple windbreak wall

The cold damage can be prevented by setting up cold-proof and wind-proof walls and cold shelters. The method is as follows: in the north of the fish pond, a wind barrier with a height of more than one or two meters is built with straw or soil, and a dustpan is built on both sides of the east and west to reduce the attack of the north wind. Drainage ditches should be built around the pond to prevent stagnant water from flowing into the pond and reduce the temperature of the pool water. The wall of the north windshield wall can be dug 40 cm from the bottom of the pool-two cold shelters with a depth of 2 meters and a diameter of 0.8 meters. The walls of the cave can be built with bricks or ceramic pipes, and fish can hide in the shelter when the cold wave strikes. Practice has proved that this method has the advantages of cold protection, low cost and obvious effect.

2. Increase the depth of the pond

Generally speaking, a pond with a leeward to the sun and a water depth of more than 2 meters can make the fish survive the winter safely, as long as they do not encounter extremely cold weather, it is no problem to survive a normal winter. At the same time, the water of the overwintering pond can not be at rest for a long time, and the water can be changed appropriately according to the local temperature, and the total water can be changed every time to prevent water pollution.

3. Feed properly to maintain the physique of fish in the pond.

In the past, many fish farmers stopped feeding in winter and began to feed again at the beginning of spring. In fact, if you can feed properly when overwintering, it can not only keep the fish from losing fat, but also increase the cold resistance of the fish, especially the high-protein diet. Feeding high protein diet can improve cold resistance and prevent the physical decline of overwintering fish. attention should be paid to nutritional collocation, especially the balance of amino acids and the adequacy of vitamins and trace elements. The law of feeding fish feed should also achieve "three determinations", that is, quality, timing and quantity. The rhythm of feeding in winter must be well mastered. If there is too little feeding, the physique of the pond fish may be weakened, the intestines and stomach walls will become thinner, lose fat and grow slowly; if you feed too much, the fish will not only cause waste, but also lead to the deterioration of the water quality of the pond.

4. Oxygenation, insecticidal and disinfection cannot be stopped.

The pond will be lack of oxygen in winter, if the aerator is turned on properly in winter, it can make the water in the pond more alive and the dissolved oxygen in the water better. In addition, the water surface which is still for a long time is easy to freeze in winter, and once it freezes, it will be even more troublesome. The water quality of the pond is easy to age in winter, and fish farmers should regularly apply microbial agents to improve the water quality. the low water temperature leads to poor algae vitality and aging, slow metabolic renewal and less phytoplankton. In particular, the silver carp in the pond with old water is also prone to diseases such as Anchor head scab under the condition of hypoxia, so it is necessary to apply insecticides in time to effectively control the cold damage and diseases before a substantial drop in temperature. when there is a sunny day for 2-3 consecutive days, you can choose to use universal insecticides to kill insects. After killing insects, it is recommended to use disinfectant to promote the wound caused by parasites on the fish can be repaired in time to avoid infection.

5. Build a plastic greenhouse

It is better to build a plastic greenhouse than a wind wall or a cold shelter. The method is to build a "human"-shaped roof along the edge of the pond with bamboo or wood. The distance from the ground to the roof is about 2.5 meters, covered with two layers of plastic film and connected to the edge of the pond to form a sealing cover. The surrounding soil can be used to seal the film. At night or rainy days can be covered with thick grass curtains to maintain the temperature in the shed, in sunny days can be properly opened grass curtains and other covers, the use of solar water supply to increase the temperature. When the water temperature is too high, it is necessary to ventilate and add some new water. If the breed is of high economic value and is not cold-resistant, heating facilities should be adopted if necessary.