Key Technical Points for Fish Pond Management in Low-Temperature Winter Weather

In winter, when temperatures are low, aquaculture farmers all know that fish are less active and have little desire to feed. If fish farming management is neglected at this time, it can easily cause large numbers of overwintering fish to die, thereby affecting farmers' economic interests. The successful overwintering of fish is influenced by many factors, including pond conditions, the health of the fish themselves, and the farmer's management of the pond. QinNongNet here summarizes several points to note in winter fish pond management, hoping to provide farmers with some help, so as to increase the survival rate of fish and ensure safe overwintering.

The precautions for winter fish pond management are mainly explained from five aspects: pond cleaning, water filling, fish density control, disease prevention and control, and comprehensive management. Let's take a specific look below:

I. Clean the pond

When aquaculture ponds accumulate more silt, the pond bottom deteriorates, which easily leads to an increase in toxic and harmful substances and causes water pollution. Therefore, removing excess silt from aquaculture ponds in winter can significantly improve the survival rate, growth speed, yield and benefits of farmed fish. After removing the silt, it is best to expose the pond to the sun for about 10 days and use quicklime to clear the pond, creating a good overwintering environment for the fish. Then add new water, and after about 10 days when the effect of the lime has disappeared, the fish can be stocked.

II. Pay attention to adding water

In winter, rainfall decreases and the water level is relatively low. The pond should maintain a water depth of at least 1.5 m. When the water level is too low, water should be added. When adding water, add it early and frequently. Do not add too much water at one time, so as to avoid causing too great a change in pond water temperature, which would increase fish activity and be unfavorable for overwintering.

III. Control density

If the density is too high during overwintering, it will cause oxygen deficiency and also very easily cause fish diseases. If the density is too low, it will also waste resources. Therefore, the appropriate stocking quantity and fish mix ratio need to be determined based on experience and actual conditions. In a pond with a water depth of 1.5 m per mu, about 30,000 fingerlings of about 10 cm can overwinter.

IV. Prevent and treat diseases

Fish diseases in winter are often overlooked, but they can also bring certain economic losses. The cases that may appear in winter mainly include the following:

1. Frostbite

When the water temperature drops to 1°C, fish begin to enter a state of paralysis. When the water temperature drops to minus 3°C, grass carp, silver carp and bighead carp will freeze to death. Therefore, before the severe winter arrives, deepen the pond water, do a good job of cold protection and heat preservation, carry out feeding management well, improve the fish's physique, and enhance their cold resistance;

2. Costiasis

Costia invading the gills and skin of fish will form a layer of blue-gray mucus. When the disease occurs, prepare a mixture of copper sulfate and ferrous ammonium sulfate in a 5:2 ratio. For each cubic meter of water, use 0.7 g of the mixture dissolved in 3 kg of water and splash it evenly over the whole pond. In addition, soak the fish in 3% salt water for 30 min;

3. Dropsy

During treatment, change the water once every 3-5 days. For each mu, use 15 kg of fresh masson pine leaves, crush them, mix with 25 kg of water, and splash evenly over the whole pond;

4. Chilodonelliasis

The body surface and gills of diseased fish secrete large amounts of mucus, forming a gray film-like layer, causing the fish to die from breathing difficulties. The treatment method is the same as for costiasis; ⑤ Saprolegniasis. Be careful not to injure the fish during capture, transportation and stocking of fingerlings. For treatment, use 2-3 g of gallnut per cubic meter of water, boil it into 5 kg of decoction, then add 10 kg of water and splash evenly over the whole pond. In addition, the fish can be soaked in 5% salt water for 5 min.

V. Strengthen management

Management work must not be neglected, and fish activity should be checked in a timely manner. In winter, there is less sunlight, and photosynthesis by phytoplankton weakens, often causing insufficient dissolved oxygen in the aquaculture environment. At the same time, be careful not to apply organic fertilizer, reduce dissolved oxygen consumption, and prevent fish from oxygen deficiency in winter. During overwintering, fish do not completely stop feeding. In warmer, windless weather, feed a small amount according to actual conditions. Patrol the pond frequently and solve problems promptly when found.

The above is what QinNongNet introduces to everyone about fish pond management during low-temperature winter periods. It is hoped that farmers, by reading this article, can strengthen fish pond management, increase the overwintering survival rate of fish, and thereby increase their economic returns.