Capturing undersized hilsa is devastating the Bay of Bengal fish population

SAIKAT K BASU

Widespread capture of undersized hilsa (locally called jatka or khoka) along the northern Bay of Bengal — especially in coastal West Bengal and adjacent marine/estuarine areas — is reducing recruitment, degrading spawning stock and threatening the long-term productivity of the hilsa fishery. Weak enforcement, economic pressure on fishers, and use of fine-mesh/illegal gears keep juvenile mortality high, undermining both ecology and livelihoods.  Removing the juveniles before they mature prevents them from returning to spawn, so fewer adults reproduce next season — a classic recruitment collapse that, repeated year after year, shrinks the population. 

Juvenile hilsa (< ~200–500 g, often <25 cm) are regularly landed and sold in markets in West Bengal and other Indian coastal areas despite formal bans and mesh-size rules intended to protect them. Markets are often “flooded” with khoka during open seasons. 

Fishers use fine-mesh gillnets and trawls that catch juveniles en masse; enforcement of seasonal/size bans is patchy. Economic need and demand (festivals, city markets) push continued harvest of small fish. 

Removing large numbers of hilsa juveniles reduces the number surviving to adulthood; this immediately lowers future spawning biomass. Over time, stock abundance declines.  Heavy juvenile removal skews the population toward fewer, older fish — reducing resilience to environmental variability. Hilsa are anadromous (sea?river) and rely on estuarine nursery habitats; heavy coastal fishing and habitat stressors compound the damage from juvenile removal from natural habitats. 

The key socio-economic factors keeping undersized catch high are listed below: 

1. High market demands (urban/seasonal festivals).

2. Poverty and lack of alternative income for fishers.

3. Use of illegal/fine-mesh nets and long trawls in estuaries.

4. Weak or inconsistent enforcement of size bans and closed seasons. 

The easy cash from selling many small fish benefits middlemen and some fishers. However due to declining catches, lower incomes, and more dependence on imported hilsa from adjoining Bangladesh and Myanmar; as local stocks fail to recover, harming artisanal fishing communities. Bangladesh has very successfully implemented strict seasonal closures, no-take sanctuaries for jatka, mesh-size controls and conditional cash incentives for fishers; these measures, combined with monitoring, have helped revive parts of its hilsa fishery. The contrast shows that policy, enforcement and fisher incentives can rebuild the stock. 

Some of the conservation efforts for hilsa needs strict enforcement of size limits and closed seasons for estuarine/coastal hilsa fishing coupled with visible patrols and market checks.  Ban or tightly regulate fine-mesh nets in nursery/estuarine zones and control trawler effort in migratory corridors. Community co-management together with incentives could include conditional cash transfers, gear buybacks, livelihood alternatives (eg. aquaculture, portering, mangrove-related jobs) reduce poaching of juveniles. Protected nursery sanctuaries with local participation and seasonal no-take rules, modeled on successful zones in the region. Market interventions such as reasonable traceability/market bans on undersized hilsa, consumer awareness campaigns (avoid buying khoka), and penalties for sellers. Regular stock assessments, size-structure monitoring and research on habitat needs to guide adaptive management. 

Capturing undersized hilsa is not a short-term harvest problem only; as it removes the very next generation that would sustain the fishery. Without rapid, enforceable measures that combine regulation, fisher incentives and market controls, coastal India risks long-term decline of hilsa in the northern Bay of Bengal, with serious ecological and economic consequences. The Bangladesh experience shows recovery is possible when policy, enforcement and fisher livelihoods are addressed together.