Sundarbans ecosystem faces major threat

Kolkata (PTI): Industries located along the Gangetic delta in Haldia, Kolkata and its outskirts are polluting the fragile ecosystem of Sundarbans, home to 40 lakh people and the Royal Bengal Tiger. The research, conducted by Calcutta University and Techno India University, says there has been a steady increase in the percentage of toxic heavy metals leading to the gradual deterioration of water there. The scientists studied presence of zinc, copper and lead in the body of a shellfish species, commonly known as the Indian white shrimp, to assess the damage. Found abundantly in the water of Sundarbans, which has the largest mangrove forest in the world, Indian white shrimp is commercially important too. "The low salinity and intense industrialisation in the Hooghly estuarine stretch is responsible for the high concentration of heavy metals in the shrimp muscle sampled from stations in and around the western side of Sundarbans," lead researcher and marine scientist, Dr Abhijit Mitra said. Heavy metals in the white shrimp's muscle exhibit a more or less similar order as that in water. Interlinked by a complex network of tidal waterways and dotted with small islands of salt-tolerant mangrove forests, this biodiversity-rich world heritage site is famous as the last surviving coastal habitat of the Royal Bengal Tiger. Though heavy metals such as copper, zinc and lead are normal constituents of marine and estuarine environments, additional quantities through industrial wastes or sewage enter the biogeochemical cycle and pose negative impact.