Bay of Bengal: depleted fish stocks and huge dead zone signal tipping point
Long treated as a bottomless resource pit, over-exploitation of the ocean, pollution and rising sea levels are having a catastrophic impact on life in the bay
A fish market at Nagor harbour in Nagapattinam, Tamil Nadu, India. Catches consist largely of species like sardines, at the bottom of the marine food web.
A fish market at Nagor harbour in Nagapattinam, Tamil Nadu, India. The bay can provide only a meagre living: 61% of fisherfolk live below the poverty line. Photograph: Dhiraj Singh/Bloomberg/Getty Images
The Bay of Bengal’s basin contains some of the most populous regions of the earth. No less than a quarter of the world’s population is concentrated in the eight countries that border the bay1. Approximately 200 million people live along the Bay of Bengal’s coasts and of these a major proportion are partially or wholly dependent on its fisheries2.
For the majority of those who depend on it, the Bay of Bengal can provide no more than a meagre living: 61% of India’s fisherfolk already live below the poverty line. Yet the numbers dependent on fisheries are only likely to grow in years to come, partly because of climate change. In southern India drought and water scarcity have already induced tens of thousands of farmers to join the fishing fleet3. Rising sea levels are also likely to drive many displaced people into the fishing industry.
But the fisheries of the Bay of Bengal have been under pressure for decades and are now severely depleted4. Many once-abundant species have all but disappeared. Particularly badly affected are the species at the top of the food chain. The bay was once feared by sailors for its man-eating sharks; they are now rare in these waters. Other apex predators like grouper, croaker and rays have also been badly hit. Catches now consist mainly of species like sardines, which are at the bottom of the marine food web5.
Good intentions have played no small part in creating the current situation. In the 1960s, western aid agencies encouraged the growth of trawling in India, so that fishermen could profit from the demand for prawns in foreign markets. This led to a “pink gold rush”, in which prawns were trawled with fine mesh nets that were dragged along the sea floor. But along with hauls of “pink gold” these nets also scooped up whole seafloor ecosystems as well as vulnerable species like turtles, dolphins, sea snakes, rays and sharks. These were once called bycatch, and were largely discarded. Today the collateral damage of the trawling industry is processed and sold to the fast-growing poultry and aquaculture industries of the region6. In effect, the processes that sustain the Bay of Bengal’s fisheries are being destroyed in order to produce dirt-cheap chicken feed and fish feed.