VISAKHAPATNAM: Fish catch in coastal AP has plummeted by almost 40% besides registering a sharp decline in marine biodiversity and disruption in ecosystem with several endemic species becoming extinct over the last decade. This is direct fallout of indiscriminate and unscientific exploitation by trawler nets, unchecked pollution and lack of implementation of government regulations.
Researchers and experts express concern and point out that alternative methods of fish catching and livelihood for the fishing community are a must to save the marine biodiversity. B Baratha Lakshmi, director, Academic Staff College, Andhra University, who is involved in biodiversity conservation, points out that untreated release of effluents including heavy metals, chemicals and its sewage, pesticides, pharma factories and oil spills from ships have wreaked havoc on the marine life on AP coast.
Indiscriminate exploitation of resources by heavy trawler traffic and climate change has also caused a drop in fish catch. "There has been a sharp decline in fish catch by around 40% in the last one-and-a-half decade. The Bay has about 600 varieties of commercially-viable fish but more than 55 varieties of species are already on the endangered list," she says.
Owing to increase in ultraviolet radiation due to ozone layer depletion, 'phytoplankton' (food for the fish) has also depleted, disrupting the aquatic food chain, Lakshmi avers. "Moreover, when Ph (measure for acid or alkalinity) value for sea water is more or less than normal 5, fish production will also come down," she points out.
Explaining the havoc caused by trawl nets, K Sujatha of department of marine living resources, AU, says while catching the fish (mostly shrimps), many other non-target species get entangled in the net or propellers, including shell fish, juvenile finned fish, ecologically important predatory fish, dolphins, turtles and so on which are discarded as trash or used as cattle feed. "This happens because the nets are often 1.3 cm to 2.5 cm in size contrary to the government norm of 4 cm. Turtle excluding devices (TEDs) are not always used nor strict penalties are imposed," she reveals. Sujatha says very small patches of coral reefs remain in Vizag due to unregulated fishing activity.
Curiously, fish catch has stagnated at around two lakh tonnes from the sea in AP, which has a long coastline of 974 km, despite increase in demand for consumption. Maheswarudu, principal scientist, Central Marine Fisheries Research Institute (CMFRI), warns if indiscriminate exploitation and pollution are not checked, there will be severe shortage of fish. "Several fish have migrated to the deep sea waters from the coast due to heavy pollution from thermal power and pharma manufacturing units," he says.
Experts say besides building artificial reefs in the coastal areas to shelter the fish to preserve biodiversity and stop non-judicious fishing activity. Currently, around 350 trawlers are operating in Vizag. In all there are 1,341 trawlers in the state, besides 17,837 traditional boats. Though deep trawling has now been converted to tuna fish liners, it had disturbed aquatic life to a great extent. "The government needs to take up promotional projects, stop pollution especially oil spills and industry effluents, adopt cage culture in the sea and provide alternative livelihood to fishermen," Maheswarudu says.