Why hilsa is disappearing from Bangladeshi plates: Pollution, overfishing and low rainfall

This year’s hilsa season is drawing to a close with consumers left unsatisfied and both traders and fishermen in despair.

Due to the lower catch, prices soared, placing the national fish beyond the reach of most households. Traders and fishermen were left frustrated by the shortfall in supply.

Amidst this scarcity, a 22-day nationwide ban on hilsa catching begins on Saturday and will continue until 25 October to protect brood hilsa.

During this period, catching, transporting, storing, marketing and selling hilsa is legally punishable, the Department of Fisheries has announced.

The initiative has been introduced on the basis of scientific evidence, taking into account the breeding cycle. Last year the ban began on 12 October, but this year it has been brought forward.

Fishermen, however, have called for a review of the timeframe.

Officials explained that every year the ban is imposed between the new moon and full moon of the month of Ashwin, when brood hilsa migrate from the sea into rivers to spawn.

Catching them during this period, they warn, would cause a catastrophic collapse in future production.

Bangladesh began a jatka (young hilsa) conservation programme in 2003–04, which gradually boosted production. From 2008, an 11-day ban on catching brood hilsa was imposed around the Ashwin full moon.

Later research showed that hilsa spawn during both the full and new moons, leading to the current 22-day prohibition.

According to Department of Fisheries data, July, August and September are regarded as the peak season. This year, the catch during July–August stood at 29,519 tonnes. Last year, the figure for the same period was 40,291 tonnes. That means the catch fell by 10,771.78 tonnes this year.

Overall, national production in the 2023–24 financial year fell to 529,000 tonnes, down from 571,000 tonnes in 2022–23. Projections suggest the 2024–25 harvest will decline further.

Researchers point to rainfall, temperature, river current, depth, flooding, food supply and water quality as crucial factors in hilsa spawning and harvest.

In southern rivers, siltation and sandbars have reduced depth, while industrial waste has polluted waters and raised temperatures. Rainfall during monsoons has also been unusually low in recent years.

According to Molla Emdadullah, project director of the Hilsa Resource Development and Management Project, not only hilsa but the catch of all fish species is declining.

He told Prothom Alo, “Overfishing has depleted stocks. The rule is to harvest only 30 per cent while leaving 70 per cent of the total stock. But indiscriminate fishing with illegal fine-mesh nets and local trawlers is killing fish of all sizes. Overharvesting of larger fish has also led to shortages in the stock.”

A fisheries department survey found hilsa migration is blocked at 17 points across the Meghna-Tentulia estuary and adjoining rivers, including 14 points on the Meghna itself.

Experts say the depth of estuaries has fallen, hampering hilsa migration. While 30 feet of water is required for free movement, many estuaries now fall to just 8–9 feet during low tide.

According to the Trading Corporation of Bangladesh (TCB), hilsa prices this year have risen by about 33 per cent compared to 2023.

The Consumers Association reported that the price per kilogram was Tk 417 in 2010, Tk 789 in 2019, and has soared to Tk 3,000–3,500 in 2025.

Mir Mohammad Ali, assistant professor at Sher-e-Bangla Agricultural University’s Aquaculture Department, told Prothom Alo, “Hilsa is a highly sensitive species. When its habitat changes, it alters its migratory routes.”

According to him, apart from the construction of coal-based power plants along the Ramnabad River in Kalapara and the Payra-Bishkhali-Baleshwar estuaries in Barguna, industrialisation around breeding grounds has polluted rivers, forcing hilsa to change course.

“This is directly affecting the country’s hilsa production,” he added.