Responding actively to illnesses on farmed shrimp in adverse weather

Unfavorable and extended hot weather, along with the fact that certain regions did not maintain a suitable environment for shrimp farming, resulted in disease outbreaks and sluggish shrimp growth.

Shrimp farmers in Hoa Hiep Trung said that the recent hot weather struggled shrimp farming. Photo: KS.

Shrimp farming was not easy

Le Thanh Sang has a two-hectare white-leg shrimp farm in Hoa Hiep Nam ward (Dong Hoa village).

Due to poor weather conditions, fluctuating sunlight, and rain, which resulted in changes in the culture environment, farmed shrimp developed slowly and illnesses spread. In which the scenario of ill and dead shrimps occurred after just two months of development in two fresh ponds. As a result, the family was forced to harvest "early" and sold the shrimp at a loss of almost VND 10 million.

The second shrimp harvest was subjected to prolonged scorching heat and some unseasonal rainfall, which weakened the shrimp's resistance and growth capacity. After three months of poor yield harvesting, he earned just around VND15 million in profit. The family is presently stocking shrimps on an area of about 1.4 hectares for the third crop. Shrimp farming has been operating for more than 1.5 months and is progressing regularly.

Nguyen But, a shrimp farmer in Hoa Tam commune (Dong Hoa town)  owned two shrimp ponds totaling approximately 1.4 hectares in size. Although farmed shrimp did not get ill in the previous two harvests, they were undeveloped, and therefore the production was unprofitable.

“The explanation may be that severe weather conditions result in frequent changes in the agricultural environment, reducing shrimps' resistance capabilities. Additionally, as a result of the Covid-19 pandemic's impact, the selling price of shrimp is VND15,000–20,000 per kg lower than it is year after year, making shrimp farming difficult "However, he added that because the farming area is currently located in In Hoa Tam commune, there are numerous households stocking the third crop in the hope of favorable weather for a successful harvest.

According to the Department of Agriculture and Rural Development, the whole province grows 1,570 hectares of brackish water shrimp as of January 2021, with the majority of the farms located in the communes of Dong Hoa, Song Cau, and Tuy An districts. Around 48 hectares of shrimp aquaculture were afflicted with illnesses, including 30 ha with acute hepatopancreatic necrosis and 18 ha with white spot disease.

Previously, the province supported localities' use of 20% Sodium Chlorite to arrange disinfection and sterilization of the agricultural environment, as well as to treat and control epidemics.

In certain farming regions, the cause of illness on farmed shrimp is described as unfavorable weather and changing farming environments that decrease the resilience of farmed aquatic products, thus providing circumstances for infections to infiltrate and cause disease. On the other hand, the environment in many agricultural regions in Phu Yen is being deteriorated and contaminated at the moment as a result of farming operations and the residues of accumulated organic wastes.

Maintain a proactive approach to shrimp farm stabilization

During a webinar, last week on solutions for developing the shrimp industry in 2021 and implementing the Prime Minister's decision on a Strategy to develop Vietnam's fisheries by 2030, with a vision to 2045, Nguyen Van Long, Deputy Director of Animal Health, forecasted that the risk of disease outbreaks on shrimps will be high in the near future. The reasons stem from the expansion of space for new shrimp crops as the weather changes, and certain areas experience saline intrusion, ensuring that aquaculture continues to face difficulties.

At the moment, hazardous infections continue to circulate in many farming locations; adverse variables such as temperature, salinity, and severe weather fluctuations may all have a detrimental effect on farmed shrimp development, resistance, and the ease with which viruses can cause illness in farmed shrimp.

Nguyen Tri Phuong, Deputy Director of the Phu Yen Department of Agriculture and Rural Development, stated that the unit is directing affiliated units to continue coordinating with localities to organize training on disease prevention for aquatic animal predators; monitor and collect data on the status of aquatic diseases in order to quickly guide and support the use of disinfectant chemicals.

Assoc. Prof. Dr. Vo Van Nha, Deputy Director of the Aquaculture Research Institute No. 3: "Aquaculture is dependent on the aquatic environment, which has an effect on the growth and development of aquatic creatures. In which, variables The primary variables affecting aquatic animal growth are temperature, pH, DO (dissolved oxygen), and salinity. Toxic contamination variables include NH3, NO2, H2S, heavy metals, and pesticides. As a result, water quality is critical in aquaculture, influencing economic efficiency via feed utilization, growth rate, and survival rate of farmed shrimp. Aquaculture species need clean water to survive and grow optimally.