Large shrimp farming areas in Nghe An province are affected by white spot disease.
During the peak shrimp farming season of the year, many farming areas in Quynh Luu district (Nghe An province) have reported mass shrimp deaths. Authorities have determined that the shrimp deaths are due to white spot disease.
30 hectares of shrimp farms in Quynh Bang commune have been infected with disease.
Despite accumulating considerable experience in shrimp farming and proactively implementing preventive measures, this year's harvest still caused significant losses for farmers in the Quynh Bang General Agricultural Cooperative, Quynh Bang commune (Quynh Luu district). Of the more than 80 hectares of ponds and lagoons stocked with shrimp, nearly 30 hectares were infected with disease, resulting in mass shrimp deaths.
According to Mr. Ho Dinh Anh, the owner of a shrimp farm in Quynh Bang commune, shrimp fry that had just been released showed signs of disease and died very quickly within 5-15 days. Mr. Anh's family lost all the shrimp in their three ponds, resulting in hundreds of millions of dong in losses. Many other farm owners in Quynh Bang commune also suffered heavy losses due to shrimp disease.
Mr. Ho Dang Tam, Director of Quynh Bang General Agricultural Cooperative, said that the cause of the shrimp deaths is believed to be due to water pollution, intense hot weather, and poor quality shrimp fry.
“The shrimp larvae, released only 5-15 days ago, are too small to clearly identify the disease, but the farmers also didn't report it in time, making it very difficult to collect samples for testing to identify the causative agent. Currently, the cooperative continues to monitor the disease situation to report to higher authorities,” Mr. Tam shared.
According to the Department of Agriculture and Environment of Quynh Luu district, over 100 hectares out of the 465 hectares planned for shrimp farming in the 2025 main season have already been stocked. However, disease outbreaks have occurred in some localities, mainly concentrated in Quynh Bang commune. This year's main shrimp farming season lasts from the beginning of April to the end of June. This is also a period of complex weather patterns, high temperatures, fluctuating water conditions, and reduced shrimp resistance. Therefore, diseases have favorable conditions to develop and spread rapidly.
Mr. Tran Vo Ba, Deputy Head of the Nghe An Department of Livestock and Veterinary Medicine, said that regarding the mass shrimp deaths in Quynh Bang commune, the Department has taken samples and conducted tests to determine the cause and detected several dangerous pathogens such as white spot disease and acute hepatopancreatic necrosis. Of particular concern is a new disease – TPD (Tuberculosis White Hepatopancreatic Disease) in whiteleg shrimp juveniles.
“Recently, the specialized agency has received the test results for 6 out of 10 samples of dead shrimp, which were negative for TPD but positive for white spot disease. Currently, the Sub-Department is specifically reviewing the area infected with white spot disease to provide chemicals to farmers to treat the outbreak,” Mr. Ba informed.
Raising awareness of disease prevention.
In reality, when shrimp show signs of disease, many households choose to discharge wastewater from their ponds into the environment instead of reporting it to the authorities. This not only directly affects the environment but also increases the risk of disease spreading to neighboring areas.
The Provincial Department of Livestock and Veterinary Medicine recommends that localities strengthen guidance and supervision of aquaculture areas, educate people about the importance of taking samples for testing; and absolutely avoid self-treatment and draining pond water without identifying the cause and without implementing proper treatment methods.
For areas currently being used for shrimp farming, farmers need to closely monitor shrimp health, check physical and chemical water factors; supplement vitamins and minerals to boost immunity; erect net barriers to prevent crustacean intrusion; carefully treat incoming water; and avoid stocking new shrimp in areas where disease outbreaks are occurring. In addition, it is necessary to apply biosecure shrimp farming practices, such as 2-3 stage farming, to reduce the risk of disease spread.
Currently, the Provincial Department of Livestock and Veterinary Medicine is requesting that localities with shrimp farming areas report fully and promptly on the disease situation. Besides weather factors, one reason for the outbreak is that many households do not adhere to the seasonal stocking schedule and do not pay enough attention to disease prevention, as most of them practice extensive farming.
"For ponds and lakes that have been infected with disease, farmers need to implement pond and lake treatment solutions according to the correct procedures before restocking with fish fry," advised Mr. Tran Vo Ba.
White spot disease in shrimp is caused by a virus and manifests as lethargy, sudden increased appetite followed by loss of appetite. The shrimp swim sluggishly at the water surface or drift towards the shore. White spots are observed on the shell of the shrimp, particularly on the cephalothorax, the 5th and 6th abdominal segments, and spreading throughout the body. Sometimes, the shrimp also show signs of reddening of the body. Once the white spots appear, mass mortality occurs within 3-10 days, with mortality rates ranging from 80% to 100%.
