Aquatic species dying from chemical reaction in haor water

Experts say the water in the haor regions in Bangladesh is not radioactive. They believe the recent deaths of various aquatic species in the wetlands have been caused by a chemical reaction in the water. As news of the deaths of different aquatic species, including fish and snails, was picked up by the media last week, many theorised that the water may have become tainted by radioactive waste infused water flowing down from the uranium mines in Meghalaya, India. However, a three-member team led by Bangladesh Atomic Energy Commission member Dr Dilip Kumar Saha has been looking into the matter and has debunked the theory. Dilip said on Sunday: “We have collected 25 samples from five haor regions and did not find any radiation in the water. “In a normal environment, there is usually a radioactivity range of 0.20 to 0.50. In the haor water, the radioactivity reading is at 0.10.” The atomic energy team sent the samples to their Dhaka lab for further analysis, but said it would take 28 days to get the final results. According to the Department of Fisheries, some 50 tonnes of fish have died since the country’s northeastern part, commonly known as haor region, was flash flooded in early April. Bangladesh Fisheries Research Institute’s Chief Scientific Officer Dr Masud Hossain Khan claimed that a chemical reaction in the water was the main cause of these deaths. He noted that aquatic life forms were dying in different pockets within the haor basin, which is comprised of seven districts – Sylhet, Sunamganj, Habiganj, Netrakona, Kishoreganj, Brahmanbaria and Moulvibazar. Refuting the radioactivity theory, he explained: “Tanguar haor, Matian haor and Shanir haor were the most impacted by the flash flooding and if the cause of death for these aquatic species was radiation poisoning, then these regions would have been hit first. “However, we have seen that aquatic life which has been most affected originate in different pockets of the haor basin where the water flow is comparatively lower.” Masud believes that the ripe paddy fields, which were submerged by the flooding, had rotted and released a large amount of ammonia which in turn reduced the level of dissolved oxygen in the water. He also suggested that frequent polluting of the haor waters might also have contributed towards the deaths of the various aquatic species.