Prediction and forecast of aquaculture diseases in Liaoning Province in April 2021
By: Date: 2021-03-31 Categories: foodtechnology Tags: ,
   The weather gradually warmed in April, and the wintering period of marine and freshwater cultured species ended. Pond cultured fish gradually began to eat, but the food intake was not large. Fish are weaker, with loose scales, and are susceptible to attack by diseased organisms. Pay attention to the aging of the water in the overwintering pond and the changes in the bottom of the pond. The water temperature rises and appropriate bait is used to enhance the physique of the overwintering fish. For dividing ponds and stocking overwintering seedlings, we must do a good job of cleaning and disinfecting the seedlings. The seedlings should be disinfected during stocking. The operations of catching, transporting and stocking should be careful to prevent seedlings from being injured. In production, the time for clearing and dividing the pool should be reasonably arranged in combination with the long-term weather forecast.

   1. Beware of diseases

  1. Carp, crucian carp, silver carp, bighead carp, grass carp:prone to water mold, vertical scale disease (commonly known as white hair disease), branchial mildew, red skin disease . Focus on the main breeding areas and high-density intensive breeding areas in the province.

  2. Turbot:Prone to bacterial diseases and parasitic diseases. Focus on the Huludao factory farming area.

  3. Rainbow trout:Prone to bacterial diseases and infectious hematopoietic necrosis. Focus on Huludao, Benxi and Dandong breeding areas.

  4. Sea Cucumber:Prone to swollen mouth disease and skin rot syndrome. Focus on coastal aquaculture areas.

  5. Bulk freshwater fish:Bacterial diseases and saprolegniasis are prone to occur.

  6. River crab:Prone to sessile ciliates. Focus on the Panjin Buckle Crab Overwintering Pond.

   2. Preventive measures

   The main cause of various diseases in April is the environment (water quality) of the cultivated species and the internal factors (physical fitness) of the cultivated species.

  1. Adjust the water quality:After the winter, the water in the aquaculture pond is aging, and the bottom of the pond is heavily polluted. The water in the fish pond is mostly acidic, with a pH of about 6, which is not good for fish. Class growth. At this time, fresh water should be added or the water quality should be adjusted with probiotics, and quicklime should be sprinkled to improve the bottom quality.

  2. Strengthen nutrition:The physique of the cultivated species is very weak after overwintering, and it is prone to various diseases due to changes in the environment. Therefore, the physique of overwintering varieties should be restored as soon as possible to enhance disease resistance. When the water temperature reaches 10℃ or higher, it is necessary to domesticate and feed the bait in time. When feeding the bait, feed it once a day at a fixed point and time, preferably at noon. Therefore, the water temperature is high and most of the fish come up to find food. The bait should be combined with finely divided materials or granular materials, and the amount of bait can be flexibly controlled according to the eating situation of the fish. As the water temperature rises, the activity of the fish increases, and the food intake of the fish gradually increases, and the feeding gradually turns to normal. When feeding, it is best to add some vitamin C and vitamin E to the bait, which has an effect on strengthening the fish’s physique and improving immunity.

  3. Pay attention to sea cucumber stress response:In April, a large amount of”peach blossom water” from melting ice in rivers was injected into the coast, and the salinity of seawater, especially the estuary waters, would be greatly reduced , Some land-based pollutants increase, do not change the water blindly. It is necessary to wait for the coastal water quality to improve and the physical and chemical indicators such as temperature, salinity, and pH value stabilize before changing the water as appropriate. During this period, it is necessary to prevent the water layer of sea cucumber farming ponds from causing hypoxia, deterioration of water quality and death of the skin. The preventive measures mainly take the water circulation in the pond, and the pond with micro-holes at the bottom should be properly started at noon on a sunny day to eliminate the water layer phenomenon, increase the bottom oxygen, eliminate hydrogen sulfide, ammonia nitrogen and other toxic and harmful gases, and spray microorganisms to adjust the water quality.

  4. In the spring, when the seedlings of the cultivated species are put into the pond and transferred to the pond, try to avoid fish body injury and prevent fish body infection from causing disease.

  5. For outsourced and self-owned seedlings, the seedling quarantine certificate must be provided to ensure source control and prevent unhealthy seedlings carrying pathogens.

   For farmed species that have become ill, a licensed veterinarian (aquatic product) must be consulted for diagnosis and medication. For more disease prevention and control methods, please log on to the new version of”fish disease remote diagnosis network” (ln.adds.org.cn) to find out on the triage platform of Liaoning Province. You can also choose relevant experts for consultation and treatment.