What are the key points of winter fishery production?

As winter arrives, the focus of fishery production begins to shift gradually. Recently, the author visited Yang Zhuangzhi, head of the Chengdu Aquatic Technology Extension Station, and asked him to introduce to everyone the technical measures that farmers generally care about, such as fish pond management and overwintering of pond fish.

In winter fishery production, what work should be done as a priority so as to provide favorable conditions for high adult fish yields the following year? Yang Zhuangzhi said that, to sum up, winter @#@233@#@ should mainly focus on seven areas of work.

Pond renovation

Use the winter idle season to renovate ponds, turning small ponds into large ponds and shallow ponds into deep ponds. After renovation, the pond's water-holding capacity can be increased and the pond environment also improved. Ponds in good condition should also be repaired: drain the pond water, expose it to the sun, then dig out the excessively thick silt (keeping about 10 cm), remove weeds, and raise and reinforce the pond embankments.

Pond disinfection

Repaired ponds should be cleared and disinfected with chemicals. Commonly used disinfectants include quicklime and bleaching powder. However, quicklime has the best disinfection effect, and it can also serve as a fertilizer; clearing and disinfecting the pond should be done on sunny days. For dry pond disinfection, use 100-150 kg of quicklime per mu, or 10 kg of bleaching powder, dissolve in water, and splash evenly over the whole pond.

Reasonable stocking

Based on the stocking experience of the previous year, the pond's fertility and feed supply conditions, and the rearing method, determine the appropriate stocking quantity and fish species mixing ratio. Traditional stocking models in the Chengdu area include: stocking large-size fingerlings, with 100-150 silver carp per mu, 20-30 bighead carp, 200-300 grass carp, and 500 crucian carp; or another model with 150-200 silver carp, 25 bighead carp, 100-150 grass carp, and 1,000 crucian carp.

Stock fingerlings early

Stocking fingerlings early allows the fish to adapt to the new living environment earlier, feed earlier, and grow earlier, relatively extending the growth period. Generally, the period from the Winter Solstice to the Start of Spring is the best time to stock fingerlings, because during this period the air temperature and water temperature are relatively low, the fish scales are tight, and the fish body is not easily injured during catching and stocking operations, which can reduce the incidence and mortality of fingerlings. Fingerlings should be stocked on sunny or cloudy days when the temperature is not too low; rainy days with excessively low temperatures, or snowy, freezing, and windy weather can easily frostbite the fish body and are not suitable for stocking.

Fingerling quality

Stocking qualified fingerlings is an important condition for high and stable adult fish yields. The size of stocked fingerlings should be larger rather than smaller; generally, one-year-old fingerlings are required, with a small head, broad back, fat and strong body, complete scales and fins, lively swimming, bright body color, and no disease or injury.

Disinfection and immunization

When fingerlings are put into the pond, they should be soaked and disinfected with chemicals for 5-10 minutes. The chemicals include potassium permanganate at 30-40 g per cubic meter of water, or salt at 3-4%, or trichlorfon at 8 g per cubic meter of water. For grass carp and other fingerlings, injection with an immune vaccine gives better results.

Feeding management

As the saying goes, "three parts stocking, seven parts management." After fingerlings are put into the pond, if the weather turns cold, deepen the pond water to prevent freezing; when it is sunny and the temperature is relatively high, appropriately feed some fine feed to ensure the fish's feeding needs and promote growth. Normally, persist in patrolling the pond, which helps discover and solve problems early. In short, as long as you manage the pond water well, you can raise the pond fish well.