The Jellyfish Surge in the Bay of Bengal
The Bay of Bengal is seeing a significant shift in its marine life. Instead of the usual fish catches, fishermen are pulling up jellyfish. This change has been noticeable since late January and became more evident in February. The reason? A prolonged dry spell along with the effects of climate change.
There has been very little rainfall since November. This lack of rain has kept sea temperatures high, increased salinity, and worsened ocean acidification. As a result, many fish species are struggling to survive in their traditional habitats and are moving to cooler waters. On the other hand, jellyfish thrive in these warmer, more acidic conditions. “The higher the temperature and acidity, the more favorable it becomes for jellyfish,” says Tanvir Shahriar Rimon, CEO of Rancon Sea Fishing.
In deeper waters, particularly beyond 40 meters, fishermen are noticing dense swarms of jellyfish. Fishing trawlers are returning with drastically reduced catches. “Many trawler owners are having a tough time covering their fuel costs,” Rimon adds.
Experts believe the situation won’t improve without rainfall. “If it rains, the sea may cool down, and jellyfish could disperse. But if the dry conditions continue, the jellyfish problem will likely persist,” warns Enam Chowdhury, president of the Bangladesh Marine Fisheries Association.
This isn’t the first time jellyfish have flourished in the Bay. Similar situations occurred not too long ago. In 2024, a severe jellyfish outbreak left many vessels unable to meet even their fuel expenses. Scientists highlight that climate variability events like El Niño can worsen ocean warming and acidification, which significantly impacts fish distribution.
A recent study in Marine Environmental Research shows that rising sea temperatures (by 1.5–3°C) lead to faster jellyfish reproduction. Marine researcher Dr. Mazharul Islam points out that the ocean’s absorption of carbon dioxide is increasing water temperatures and salinity, raising jellyfish populations further. Overfishing is also part of the issue, as it reduces fish that might otherwise keep jellyfish numbers in check. “When large fish populations decline, jellyfish take over, leading to a disrupted food chain,” he explains.
Bangladesh’s fishing industry mainly targets species like tuna and mackerel in the Bay of Bengal. The sector flourished after maritime boundaries were established in 2012 and 2014, allowing access to new fishing grounds. However, factors such as high fuel costs and aging vessels continue to threaten profitability.
As ocean temperatures rise earlier each year, fishermen are worried that disruptions may happen more often. Until consistent rainfall cools the waters, the fishing industry faces an uncertain future, burdened not just by economic pressures but by a changing marine environment.
For more insights on this topic, check out the latest report from the World Bank.
