Drop of poison, sea of consequences: How poison fishing is wiping out Sundarbans’ ecosystems and livelihoods
For those looking to spend as little time as possible catching fish, it might seem like an efficient method. But in reality, poison fishing is a destructive shortcut
Komla Sarker, a fisherwoman from Mongla upazila in Bagerhat district, does not condone poison fishing. But the illegal yet increasingly common practice in the Sundarbans is continuously destroying the ecological structure of the world's largest mangrove forest and endangering both biodiversity and human health.
The implications go beyond just environmental degradation. For traditional fishers who practise organic methods, the stakes are increasingly high.
"The people who practise poison fishing are causing us harm. They poison a certain part of the river, but the water carries the poison to other areas," she said.
"We get fewer fish now. Climate change has already drained our income and fish supply. If this practice of poison fishing continues, we might be forced to start begging to survive," Komla added.
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According to Jomir Uddin, a resident of Mongla, fishermen use engine-powered boats to enter the Sundarbans. "They use poison; what they use is a kind of syrup. If anyone spills a few drops in the water body, within a few minutes, fish, crabs and other aquatic species die and wash afloat on the shore."
The fishermen first block two sides of a canal or river with nets, then they spill the poison in the water and catch the fish and other aquatic species that surface and leave the area, leaving the poisoned water behind, he further explained.
"Poison fishing is a serious concern for the biodiversity of the forest. It ruins the lives of all kinds of species in the forest. The government took initiatives under the Forest Act, but no one followed the rules. Strong syndicates operate in those areas — powerful ones that no one can stop."
For those looking to spend as little time as possible catching fish, this might seem like an efficient method. But in reality, it is a destructive shortcut. Using these toxic chemicals, usually pesticides masked as agricultural supplies, kills more than just fish. It breaks the entire aquatic food chain and even hurts the ecosystem's core.
Another fisherman from Mongla, Sharif Majhi, said, "People buy these poisons illegally. They say it's for farming, but they use it in the rivers. The sellers know the truth but still sell it to them for a mark up."
Despite a 2021 High Court verdict prohibiting poison fishing, enforcement is very weak. The root of the issue, according to environmental experts, lies in poor governance and syndicate control.
Professor Dr M Shafiqul Islam from the Department of Marine Science and Fisheries at the University of Chittagong said, "Poison fishing is a serious concern for the biodiversity of the forest. It ruins the lives of all kinds of species in the forest. The government took initiatives under the Forest Act, but no one followed the rules. Strong syndicates operate in those areas — powerful ones that no one can stop."
The Sundarbans has a unique coastal ecosystem. It is shared between Bangladesh and India, and the Bangladesh portion alone is home to 210 species of white fish, 24 species of shrimp, 14 types of crabs, 43 species of molluscs, and many species of lobster, according to the Bangladesh Forest Department.
About 1.7 million people reside in the surrounding areas, most of whom depend either directly or indirectly on the Sundarbans' resources for survival. These include fishing, crab collection, honey gathering, and woodcutting, and these are essential for the region's economy. Locals are increasingly reliant on the forest's bounty.
To regulate this dependency, the Forest Department issues permits for resource collection, restricting entry during the breeding season from June to August. Yet, cracks in enforcement have allowed the practice of poison fishing to continue.
Fish caught with poison rarely make it to formal markets in raw form. Instead, many are dried in distant forest areas, covered up as standard dried fish. Others are sold in cities, far from their toxic origins.
"This is very dangerous for health. If you do not know that a fish is caught with poison and eat it, it will slowly damage your organs. Over time, it can lead to chronic diseases just from consuming shrimp, crabs and other poisoned fish," said Dr Shafiqul Islam.
This hidden health risk highlights another major failure — the lack of accountability and awareness in the supply chain. Consumers in urban centres remain totally unaware of the source of their seafood, leaving them vulnerable to toxic exposure.
Authorities also acknowledge the problem but struggle to keep them in check.
"We do not deny it's not happening, but our effort should also count. A few months ago, we arrested three people while catching fish with poison. We filed a case under the Forest Act. Our efforts are ongoing," said Liakat Khan, former Forest Conservator of Khulna Circle.
Law enforcement agencies also claim to have conducted raids and issued warnings, but the results are limited.
"We have warned the locals many times and have taken initiatives to stop this. We have also conducted raids with other security agencies, but they still do not stop," said Subrata Deb Nath, Duty Officer at Mongla Police Station.
One reason for this failure is that poison fishing is often carried out by organised groups. These syndicates operate by exploiting gaps in governance and enforcement. For local fishers, going up against them is not only difficult — it is dangerous.
The Sundarbans is more than just a fishery. It is a biodiversity hotspot that hosts the fight against cyclones and rising sea levels. Poison fishing undermines its ecological balance in ways we are only beginning to understand.
The chemicals used in this practice do not simply vanish. They seep into the mangrove soil, disrupt breeding cycles, and kill juvenile fish and non-target species. Over time, this damages the regenerative capacity of the forest itself.
"It is not far when the Sundarbans will be totally out of fish. It's happening in front of us," said Sharif Majhi.
The irony lies in the fact that the very communities dependent on these resources are also the ones facing their collapse. The more fishers resort to poison, the fewer organic fish remain. The fewer fish there are, the more people turn to shortcuts to survive. It's a vicious cycle spiralling towards ecological collapse.
The solution to poison fishing is not merely a legal or policing issue. It needs a comprehensive response that addresses both the ecological and socio-economic dimensions of the threat.
"The only way for this to stop is for people to become more aware. Without proper knowledge and awareness of the environment and climate change, this can never be stopped," said Mamun Ur Rashid, Coordinator of Badabon Sangho, a community-based NGO working in Mongla.
Awareness campaigns, stricter regulation on pesticide sales, and stronger forest management practices must work together. But more importantly, alternative livelihoods need to be developed for those who see poison fishing as their only option.
Without socio-economic alternatives, efforts to police the forest will remain unsustainable. Locals must be made stakeholders in the conservation of the Sundarbans, not just subjects of law enforcement.
