White spot disease prevention for farmed shrimp

(Baonghean) - As of May 10, 2014, the total area of ​​shrimp farming affected by disease in the province is 32/900 hectares of total farming area. This year, in particular, the pathogen causing the white spot virus appeared earlier and more than in previous years, accounting for 15 hectares. White spot disease appeared mainly in localities such as: Mai Hung Ward, Quynh Di - Hoang Mai Town, Quynh Bang Commune, Quynh Thanh - Quynh Luu District, Nghi Thai Commune - Nghi Loc District, Hung Hoa - Vinh City.

To properly manage shrimp ponds, control diseases and limit widespread spread, farmers need to take the following measures:

1. For areas where shrimp seeds have not been released:

- Renovate ponds and lagoons according to technical procedures. There must be a settling pond and water must be treated before being put into shrimp ponds with chlorine at a concentration of 30 ppm (ie 30 grams/m3 of water).

- Do not use pesticides, banned chemicals or chemicals of plant protection origin to treat the pond environment.

- Use nets to set up fences around the pond banks to prevent the entry of intermediate hosts (crabs, clams, mud crabs, etc.) carrying white spot virus into the pond system.

- Closely monitor shrimp disease situation, weather developments and notify the Aquaculture Department of environmental monitoring results to have appropriate plans for water intake, treatment and stocking.

- Use fish with clear origin and must be tested for white spot virus, taura virus, luminous bacteria... and meet requirements before being released for farming.

2. For areas where shrimp seeds have been released:

- Closely monitor and manage well the environmental factors of the pond such as temperature, pH, DO, salinity, H2S, NH3... Spread lime around the pond bank before and after rain to reduce turbidity and stabilize the pH of the pond. Maintain alkalinity of 120mg/l or more by applying CaCO3 or Dolomite at night every 3-5 days. Use probiotics and biological products (on the list of permitted circulation in Vietnam) during the farming process to reduce toxic gases and help improve water quality in the pond.

- In addition to a reasonable and quality feeding regimen, it is necessary to regularly supplement vitamins, minerals, etc. to increase shrimp resistance.

- Increase water fan time and install an additional bottom aeration system in the pond to increase the amount of dissolved oxygen in the pond.

- Every 7-10 days, farmers should use disinfectants containing the active ingredient iodine at a dose of 1-2 ppm and spread evenly into the pond to prevent and eliminate the ability of free virus microorganisms in the water to infect, especially when other ponds in the farming area have white spot disease.

- Add and repair nets around the pond banks to prevent the entry of intermediate hosts (crabs, clams, crabs, etc.) carrying white spot virus into the pond.

- Drive away birds that eat aquatic animals that appear in the farming area, because they can carry pathogens from epidemic outbreaks into the farming area.

- To avoid spreading pathogens between ponds, it is best to use separate production tools (nets, nets, boats, etc.) for each pond.

- During the period when the disease is complicated, limit the amount of water taken directly from the environment into the pond. In case of having to take water, take it into the settling pond and treat it with 30ppm Chlorine (30g/m3), run the water fan continuously until all the Chlorine is checked before pumping it into the pond.

- Regularly monitor the disease situation in the area to have the best disease prevention measures.

3. For diseased shrimp ponds:

- When shrimp in the pond show abnormal signs, or are suspected of having white spot disease, it is necessary to immediately report to the commune veterinary officer, the commune People's Committee, the cooperative, the community group, and take samples for testing to determine the exact cause of the disease. When the test result is positive for white spot virus, the treatment plan must follow the instructions of the veterinary officer.

- Absolutely do not discharge untreated diseased pond water into the environment.

- Do not bring food, tools, and aquatic animal waste out of the diseased area to limit the spread of disease.

- To continue reproduction, in addition to good pond renovation, it is necessary to ensure treatment time to destroy residual pathogens in the pond (minimum 30 days).

Lusty