N Bengal launches fish vaccination trial to boost hatchery survival rates

Jalpaiguri: In a groundbreaking move for aquaculture in North Bengal, vaccines have been administered to fish for the first time—marking a significant leap forward in disease prevention and fry survival rates. The initiative was launched by the Fisheries department of the Krishi Vigyan Kendra at Ramsai in Maynaguri, Jalpaiguri, under the West Bengal University of Animal and Fishery Sciences.

The trial began on Saturday at the Jalapesh Hatchery in Votpatty, Maynaguri, where Rohu and Catla fish were vaccinated using the CIFA BROOD vaccine. Before vaccination, synthetic spawning hormones were injected to stimulate breeding in stagnant water—a method typically required for species that naturally spawn in flowing rivers.

“Out of one lakh fish eggs that hatch naturally, only about 42,000 survive to the fry stage and eventually just 20,000 to 28,000 can be kept alive,” explained Indranil Ghosh, fisheries scientist leading the trial. “High mortality due to disease has been a major cause of financial losses for hatchery-based fish farmers. This new method could drastically improve survival rates.”

The vaccination process involves injecting synthetic hormones below the dorsal fin to induce spawning, followed by the CIFA BROOD vaccine near the ventral fin.

The fish are then released back into the water. The dual-step procedure not only boosts immunity but also enhances the health of eggs and fry, significantly reducing mortality and promoting growth in stagnant ponds.

Ghosh added that the method poses no side effects and is expected to increase the production of high-quality fish. “Species like Rohu, Catla, Mrigal, Calbasu, and Silver Carp don’t usually breed in stagnant water. This technique can change that, benefiting fish farmers both biologically and economically.”

Kaushik Roy, a fish farmer at the hatchery, welcomed the move: “We used to lose a large portion of our eggs and fry. With this vaccine, we’re hopeful those days are behind us.”

This marks the first-ever use of vaccines in aquaculture across North Bengal. The trial will continue for a year to monitor results, with the Fisheries department aiming for a 35 per cent to 45 per cent survival rate. If successful, the initiative will be expanded to other hatcheries during next year’s monsoon season.