After nearly two decades of uninterrupted growth, hilsa production in Bangladesh has been falling steadily for three years. The average weight of the fish has also begun to drop, raising concern among researchers.

As a result, the six-year project the Department of Fisheries launched in 2020 to raise hilsa production has in effect ended in failure. With that project due to end this June, preparations are under way at government level for a new one.

Yet in 2018, after scientists at Bangladesh Agricultural University decoded the complete genome of the fish, it was hoped that Bangladesh would make major progress in hilsa conservation, production and quality.

Instead, the fall in production has been acknowledged by Molla Emdadullah, director of the Department of Fisheries' Hilsa Resource Development and Management Project. He told BBC Bangla that sustaining the growth seen over the two decades up to 2021 has, for various reasons, now become a challenge.

Hilsa researcher Dr Anisur Rahman, a former director of the fisheries science institute, said: "Big hilsa had started to arrive. It is urgent to identify why production and weight suddenly began to fall. Small hilsa are increasing in the market and big hilsa are decreasing — this is dangerous for the hilsa population too."

According to the Bangladesh Fisheries Research Institute, about 12 per cent of the country's total fish production comes from hilsa, and about 60 per cent of the world's hilsa is produced in Bangladesh. The Ministry of Fisheries and Livestock claims that 70 to 80 per cent of the world's hilsa is now produced in the country.

Even so, the question of why production and the weight of the fish are suddenly falling has become a pressing one.

According to the Department of Fisheries, hilsa production was 1.99 lakh tonnes in 2002-03, and it rose on average every year after that.

"Production kept rising because of measures such as the fishing ban during the breeding season. But it began to stumble from the 2022-23 fiscal year," Molla Emdadullah said.

The effect has been a steady rise in hilsa prices over the past two years. Last week one buyer reported paying nearly Tk 3,500 a kg for hilsa weighing 900-950 grams at a wholesale market in Chandpur. At Karwan Bazar in Dhaka, sellers are asking an average of more than Tk 2,000 a kg for hilsa of 800-900 grams.

Officials say 5.71 lakh tonnes of hilsa were produced in 2022-23. Production fell to 5.29 lakh tonnes in 2023-24 and to 5.04 lakh tonnes in 2024-25.

There is no official figure yet for 2025-26, but officials' estimates suggest production was below 5 lakh tonnes.

Molla Emdadullah said that although large hilsa are still found now and then, more light fish are now being caught. In the hilsa's life cycle it must travel from river to sea, he said, and he believes the tendency to migrate from river to sea has declined because the fish are being caught at the estuaries.

According to hilsa officials and experts, after spawning in October the fish stay in the rivers for six to seven months. They then move to the sea at the end of April or in the first week of May, when the river water turns turbid.

The main hilsa grounds in Bangladesh are Chandpur Sadar and Haimchar, the Padma from Louhajang in Munshiganj to Zajira, the Gajaria river in Mehendiganj, some rivers in Barishal and Barguna, and the Tetulia river area in Bhola. From these areas the hilsa move through the south towards the sea.

With hilsa under threat from heavy catches of jatka (juvenile hilsa) and illegal fishing, the authorities began taking a range of measures from around 2000.

As part of this, from 2015 the government imposed a fishing ban in the Bay of Bengal every year from 20 May to 23 July. Since last year the ban period has been set at 15 April to 11 June.

Experts say, however, that small hilsa are being caught with current nets in the rivers, while commercial trawlers at sea are widely accused of coming into waters shallower than 40 metres to catch small hilsa.

"Small hilsa are caught at the estuaries on their way from river to sea. At sea there is illegal overfishing. So the small fish get no respite. Pollution is also hampering hilsa production in the rivers and the sea," said Molla Emdadullah.

In his view, loss of river navigability and pollution are the main reasons production has fallen. Silted chars have damaged the migration routes, and breeding grounds and nursery grounds have also been damaged, with the effect showing up in both production and weight.

The country has five hilsa sanctuaries: two on the Padma and Meghna, and one each on the Tetulia, Gajaria and Kalabadar rivers. There is also a sanctuary on the Andharmanik river in Kalapara, but it is no longer effective.

Given the complaints that commercial trawlers are freely catching small hilsa at sea, a new project focused on the sea is being considered, Molla Emdadullah said. "Even so, it may take a few years to overcome the current crisis. But steps must be taken to increase stocks by controlling the excess trawlers at sea."

Bangladesh Agricultural University is now researching hilsa along the coasts of Bangladesh, Myanmar and India, and Dr Anisur Rahman works on that project as a researcher.

"The way production and weight are falling is a matter of concern. Research is needed to establish why hilsa production and weight are declining. But if jatka are not allowed to grow, how will we get big fish? If this happens two years in a row, production collapses. Salt water pushing towards fresh water and reduced water flow can also cut production," he told BBC Bangla.

Both Molla Emdadullah and Dr Anisur Rahman say surveillance on the rivers and at sea must be stepped up to protect hilsa.

Source: Jagonews24. First published in Bengali on The Agro News.