Fish stocks collapse in the Bay of Bengal, fishermen at risk

A historic decline in fish stocks in the Bay of Bengal is reshaping both the marine ecosystem and the lives of thousands of coastal fishing families. A recent comprehensive fisheries survey shows that the stock of small pelagic species has fallen by 78.6 percent in just seven years, from 158,100 tonnes in 2018 to only 33,811 tonnes in 2025. As fish disappear, jellyfish are moving in, increasingly dominating coastal waters where fishermen make their living.

The Bay of Bengal is central to Bangladesh’s food security and economy. Fish from these waters contribute around 12–15 percent of the country’s total fish production, according to a Department of Fisheries report dated June 26, 2025. Fish provide nearly 60 percent of national animal protein intake and play a significant role in blue economy exports. A collapse of this scale therefore raises urgent concerns about the future of fisheries and the livelihoods of fishermen in these areas.

For fishing families, these environmental shifts are not abstract trends but daily struggles. Najir Hossain, a fisherman, and his wife Rokeya describe how unreliable catches have pushed them into debt. “We catch fish throughout the year, and only two months are restricted,” Rokeya said. “But fish are so few in number now that we have to take out loans just to get by.”

Their income, once relatively stable, has become uncertain. “Our husbands and sons rent trawlers from the owners and go out to sea. We used to earn a decent income from the catches,” she said. “Now that is no longer guaranteed.”

They also face enforcement pressures and insecurity at sea. Rokeya alleged that nets are sometimes confiscated or destroyed during patrols. These nets and fishing gear are worth a huge sum. On top of that, they do not own them; the trawler owner does. When they are taken or burned, the loss is huge.

Trawler owners echo these concerns. Abul Kalam, who owns around 60 fishing trawlers, says the decline has been steady and puzzling. “Five to ten years ago, we had plenty of fish. It kept decreasing year after year, but we don’t know the exact reason behind this decline,” he said.

Fishing seasons have also become less predictable. “Normally, in winter fish go deeper, and the rainy season is our peak time, especially June and July,” Kalam explained. “One trawler carries seven to eight fishermen in total. In a single trip, we can earn between 1.2 to 2 lakh taka per trawler, but the fuel and other costs are higher. Now, even in peak season, catches are low.” “After all the expenses, each of the fishermen earns around 10 thousand taka per trip.”

Higher market prices have partially offset losses, but not enough to ensure stability. “Before, when we had plenty of fish, prices were low. Now we catch less fish, but prices go up. In that sense, it kind of balances out,” he said. “Still, when catches are poor, we have to take loans to continue operations. We have labourers and fishermen whose lives depend on these trawlers.”

When fishing fails, many workers are forced to find temporary alternatives on land. “Some work as drivers for local tom-toms, while others work as day labourers,” Kalam said. “That’s how they survive.”

Marine scientists say the decline in fish and the rise in jellyfish are driven not by a single cause, but by a combination of long-term environmental and human pressures. “Factors such as climate change, global warming, pollution, and overfishing are behind both trends,” said Dr Md Ashraful Haque, CSO at the Cox’s Bazar Marine Fisheries Research Centre.

Scientists note that jellyfish are benefiting from these pressures. Dr Haque said they feed directly on fish eggs and fry, hampering recovery. “Jellyfish prey on fish eggs and fry, contributing to fish decline,” he said. He also highlighted a breakdown in predator–prey balance, noting a sharp fall in sea turtle populations, which normally keep jellyfish numbers in check.

The increase in jellyfish is also creating operational problems for fishermen. “Jellyfish get trapped in nets and gear,” Dr Haque said. “A single jellyfish can weigh 10–12 kilograms, and a swarm can easily damage or destroy fishing nets.”

Observations suggest that jellyfish sightings have increased noticeably in recent years. Dr SM Sharifuzzaman, director and professor at the Institute of Marine Sciences, University of Chittagong, said the phenomenon has become visible only recently. “Jellyfish are a recent phenomenon; we have been observing their rise over the last five years,” he said. “After February and March, when the climate gets warmer, we see the presence of jellyfish or their swarms in the sea.”

Dr Sharifuzzaman explained that jellyfish, or gelatinous zooplankton, include both small and large species that can bloom rapidly under favourable conditions. “They were once rare-maybe two or three would wash up on Cox’s Bazar beach,” he said. “Now, large numbers are stranding on the shore, and fishermen are finding them in their nets.”

What is clearer, he added, is the sharp decline in pelagic fish species, the mainstay of coastal fisheries. “We have clear evidence that pelagic species are declining at an alarming rate. An almost 80 percent decline didn’t happen overnight. It occurred gradually over many years.”

Coastal environmental conditions may be tipping the balance in jellyfish’s favour. “Our coastal and ocean waters are low in oxygen beyond a certain depth,” Dr Sharifuzzaman said. “Most fish can’t survive this, but jellyfish thrive. When natural equilibrium is disrupted, someone benefits. In this case, jellyfish.”

This imbalance is already affecting fisheries. “As jellyfish populations increase, they replace fish in fishermen’s nets,” he said. “Rising jellyfish numbers signal commercial fisheries decline, which we’ve seen alongside an 80 percent drop in pelagic species.”

Studies by the Monterey Bay Aquarium further suggest that jellyfish play a role in transferring microplastics into marine food chains. By ingesting plastic particles directly or through contaminated prey, jellyfish can pass pollution up the chain when they are consumed by larger species, deepening the ecological consequences of their spread.

For coastal communities, that shift would mean not just ecological loss, but the slow erosion of a way of life that has sustained generations. 

Ystiaque Ahmed is a journalist at The Daily Star. He can be reached at ystiaque1998@gmail.com.

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