Trawl-induced biological and chemical degradation in Bengal Offshore

摘要

Coastal and estuarine area of West Bengal offshore in India enjoys the world's largest mangrove food web named 'Sundar- bans' declared as the World Heritage Site in 1989, which exhibits excellent breeding ground of uncountable fish and other marine species. Growing population has forced intensification of trawl netting by commercial fishermen all along the offshore during the last few decades. This paper presents a case study of Shankarpur-Digha-Petua fishing zone where modern bull trawlers continuously drag bigger trawl nets through ocean bottom and obtain huge commercial catch destroying at random under-sea habitat of many non-economic but ecologically valuable marine species. Trawling has been proved to destroy many ecologically worthy juveniles occupying the primary and secondary trophic levels of marine food chain. Anthropo- genic malpractice seems to have created a great food crisis for all predators including apex species like shark, dolphin, and seal whose sustenance is suspected to be at stake leaving seafood-dependent coastal fishing population as the worst sufferer. Thus, economic profit is gained at the cost of undesired ecological loss. An effective Environmental Management Plan is also discussed here which will help keeping balance between ecology and economy to ensure conservative use of marine resources towards sustainable development of the ecology of this World Heritage Site.