Disease prevention and control in shrimp during the rainy season

During the rainy season, the brackish water shrimp pond environment in Tay Ninh province fluctuates strongly, potentially causing many diseases that reduce shrimp resistance and make them vulnerable to damage. In this situation, the provincial Department of Agriculture recommends that farmers proactively apply technical measures, strictly control water quality and breeds to protect the crop, aiming for safe and sustainable production.

Disease risk from weather fluctuations

During the peak rainy season of 2025, brackish water shrimp farming areas in the province are facing many challenges. Rainwater reduces salinity, pH, alkalinity and causes water stratification, thereby making shrimp susceptible to shock, reduced appetite, weakened resistance and susceptible to intestinal diseases, hepatopancreatic necrosis or microsporidian infection.

Shrimp farmers need to increase water fan operation to maintain dissolved oxygen and limit water stratification in ponds.

According to statistics from the provincial Department of Agriculture, the whole province has about 5,700 hectares of brackish water shrimp farming area, concentrated in the communes of Can Duoc, Phuoc Vinh Tay, Vam Co and some riverside communes. Of which, the harvested shrimp area is nearly 4,650 hectares, with an output of over 18,000 tons.

However, according to forecasts, from September to mid-October 2025, the province will experience many heavy rains lasting 2-4 days. This amount of rain will affect the quality of the ponds, reducing salinity below the appropriate threshold, increasing the risk of toxic gases NH₃, NO₂, H₂S in the pond water.

According to Deputy Head of the Provincial Department of Agriculture Nguyen Vo Thi Ngoc Giau, in the rainy season, the water environment changes erratically. If farmers do not manage well, diseases can easily break out. Specialized sectors should strengthen monitoring and promptly provide information on salinity, pH and environmental factors for farmers to adjust. Along with that, farmers should pay attention to keeping the pond water level from 1.4-1.6m, increase water fans to avoid stratification and maintain dissolved oxygen above 5mg/liter.

To minimize risks, experts recommend that farmers need to apply many technical solutions synchronously. First of all, seed selection must be given top priority. Seedlings must be purchased from reputable establishments, with quarantine certificates, ensuring they are free of at least three common dangerous diseases in shrimp: white spot, acute hepatopancreatic necrosis and EHP. Black tiger shrimp seed should be post 15 in size and whiteleg shrimp seed should be post 12 in size or larger, swimming quickly and evenly, with a deformity rate of less than 0.5%.

Regarding pond management, farmers should reserve at least 15% of the area (for earthen ponds) and 50% (for canvas ponds) for settling ponds and water storage ponds. The depth of the settling pond should be 2-2.5m to store enough water for regulation during the rainy season. In addition, about 10% of the area should be allocated for waste and sludge ponds to avoid direct discharge into the environment.

When encountering heavy rain, farmers need to reduce the amount of food by 30-50% depending on the shrimp's appetite, and spread CaO or CaCO₃ lime around the pond bank to neutralize the acid in rainwater. Increase the continuous operation of water fans to avoid stratification, and periodically add microorganisms to limit the growth of harmful bacteria.

Mr. Tran Van Cuong, a shrimp farmer in Can Duoc commune, shared his experience: “Whenever there is prolonged rain, I often add lime around the pond; reduce feeding so that the shrimp do not get shocked. Before taking new water, I always check the salinity, only taking it when it reaches 5‰ or higher, and the alkalinity is above 120mg/liter. Thanks to that, for several consecutive crops, my pond has not been affected by disease, and the shrimp have achieved good productivity.”

Towards safe and effective farming

The Department of Agriculture and Environment has directed its subordinate units to strengthen inspection and supervision of farming areas. The water environment monitoring warning system is maintained regularly in key districts to provide timely information to farming households.

Deputy Director of the Department of Agriculture and Environment Dinh Thi Phuong Khanh emphasized: “During the rainy season, the risk of disease in shrimp is very high, so the industry continues to coordinate with local authorities, cooperatives, and fisheries cooperatives to provide technical guidance, distribute documents, and provide early warnings to farmers. We encourage farmers to join together in cooperatives and cooperatives to share experiences, reduce costs, and better manage diseases.”

In addition, the province is also calling on businesses to invest in deep processing and develop a chain of linkages from breeds, feed, farming techniques to consumption. This not only helps stabilize selling prices, but also creates conditions for farmers to confidently apply biosafety measures, limit the use of antibiotics and chemicals, and move towards sustainable production.

“Farmers absolutely must not discharge untreated wastewater from their ponds into canals and ditches, which not only pollutes the environment but also spreads pathogens. The specialized sector will continue to accompany them, but the most important thing is the proactive awareness of farmers. When farmers master the techniques and follow the recommendations, the risk of disease will decrease and productivity will be more stable,” Ms. Dinh Thi Phuong Khanh advised./.

Thanh Tung

Source: https://baolongan.vn/phong-chong-dich-benh-tren-tom-trong-mua-mua-a201932.html