ICAR-CIFRI, Barrackpore Organises Disease Surveillance Following Whiteleg Shrimp Mortality in Purba Medinipur

11–15 September 2026, West Bengal

Scientists from the ICAR–Central Inland Fisheries Research Institute, Barrackpore, conducted field-level disease surveillance and diagnostic investigations following reports of mass mortality among cultured whiteleg shrimp (Litopenaeus vannamei) in shrimp farming units across the Chandipur–Nandigram area of Purba Medinipur, West Bengal.
The investigation was undertaken under the National Surveillance Programme for Aquatic Animal Diseases (NSPAAD) to assess the nature and possible causes of the mortality and strengthen disease preparedness and management among shrimp farmers in the affected area.

The ICAR-CIFRI team, comprising Dr Vikash Kumar, Senior Scientist, and Shri Asim Jana, Technical Officer, under the guidance of Dr Pradip Dey, Director, ICAR-CIFRI, inspected multiple affected ponds. The team documented clinical and epidemiological signs, pond conditions, culture practices, farm infrastructure and biosecurity measures. Dead and moribund shrimp were examined, and representative shrimp, environmental and associated samples were collected for detailed laboratory investigations.

Preliminary field observations and screening indicated the possibility of Enterocytozoon hepatopenaei (EHP) infection and Running Mortality Syndrome (RMS) as potential contributing factors. However, the scientists emphasised that these observations are preliminary and do not constitute a confirmed diagnosis. A definitive assessment will require further pathogen-specific laboratory testing and histopathological examination.

The investigation also highlighted the importance of water quality, pond-bottom conditions and farm management in disease-associated mortality. Fluctuations in dissolved oxygen and pH, inadequate total alkalinity, high organic loading and accumulation of bottom waste can adversely affect shrimp health and potentially increase susceptibility to disease.

As an immediate risk-management measure, farmers were advised to promptly remove and safely dispose of dead and moribund shrimp to minimise cannibalism and the potential spread of pathogens. They were also advised, wherever practicable, to restrict the movement of shrimp, water, equipment and personnel between affected and unaffected ponds.

The scientists recommended regular siphoning and removal of accumulated organic matter, faecal material and other bottom wastes, along with frequent monitoring and appropriate aeration to maintain stable water-quality conditions.
Farmers were further advised to adopt need-based feeding, avoid overfeeding and closely monitor shrimp behaviour and feed response during mortality events. Depending on shrimp condition, water quality and biomass, temporarily reducing or skipping one or two feeding cycles may be considered during acute mortality episodes.

Reflecting on the investigation, Dr Pradip Dey, Director, ICAR-CIFRI, emphasised the importance of strengthening disease preparedness and surveillance in aquaculture. He highlighted the need to integrate early disease surveillance, scientific diagnostics, environmental monitoring, sound pond management and robust biosecurity measures for sustainable aquaculture.

He further stressed the importance of evidence-based disease management and responsible health practices, cautioning against the indiscriminate use of antibiotics and chemicals. The investigation underscored the need to strengthen disease surveillance as a proactive system for early warning, prevention and preparedness.

Alongside the field investigation, ICAR-CIFRI conducted an awareness programme for shrimp farmers and local stakeholders, focusing on early disease reporting, routine surveillance, water-quality monitoring, farm sanitation, biosecurity and scientifically informed health management.

The farmers were specifically cautioned against the indiscriminate use of antibiotics, chemicals or other therapeutants without a confirmed diagnosis and professional guidance.

The ICAR-CIFRI team emphasised that effective disease management in shrimp aquaculture requires an integrated approach combining pathogen detection, environmental monitoring, biosecurity and sound husbandry practices.

The final assessment of the Purba Medinipur mortality event will be based on the results of the ongoing laboratory investigations. Further site-specific management recommendations will be issued to the farming community once the diagnostic findings become available.

(Source: ICAR–Central Inland Fisheries Research Institute, Barrackpore)