Fishermen from villages here claim that scores of fish varieties have disappeared or become rare since mining started on their beaches. They say that nearly 30 varieties of fish have disappeared and are rarely netted while some varieties have become extinct. Rock lobster, crabs, white fish (known locally as kudhippu meen), mackerel, sea urchins and planktons (it used to be washed ashore in plenty) are not found easily off coastal villages in Tirunelveli and Tuticorin, fishermen say. "All these varieties which were caught from the sea within a nautical mile from the shore before sand mining activities started in 1990 have disappeared," says A Mesman, a fisherman from Periathazhai in Tuticorin district. "Varieties like rock lobster used to be priced at around Rs 2,000 per kg. Poor people in the village who couldn't afford a boat or fishing gear used to catch them from under the rocks close to the shore. Rock lobster is no more found in our village. Crabs and turtles which used to nest in our beaches too no more come anymore," he says.

M Susai Antony, president of Fishermen Cooperative Society in Perumanal in Tirunelveli district, has a list of fish that have disappeared from the region, which includes sharks, sting ray, seer, barracuda, pomfret, emperor and sardines. "Most of these fish varieties have migrated beyond 30 nautical miles from the shore. Our fishermen use country boats and outboard-engine-fitted fibre boats and they can't sail so far in to the sea," he says. "The sea floor near our villages has turned barren. Some 10 years back, variety of sea plankton used to be washed ashore. Merchants used to come from Madurai to procure them. Sea urchins, considered a delicacy, are not found anymore," he says.

There seems to be no consensus on the impact of sand mining on the fish population. A fisheries scholar at a university department in Madurai says that marine species in general will prefer the shallow waters with a lot of nutrient content. Sea erosion will result in torpidity which will result in clogging of the gills in fishes and hence fish will avoid such places, he says. H Mohamad Kasim, a retired principal scientist from Central Marine Fisheries Research Institute, says the stimulation of radiation through mineral sand mining and the alteration of topography of the beach deplete sea wealth. "There are no studies taken out so far to validate the claims of fishermen but there sand mining will certainly have some impact. The marine life is under severe threat from pollution in the shore and other factors like global warming, climate change," he says.

However, J K Patterson Edward, director of Sugandhi Devadasan Marine Research Institute in Tuticorin, feels the claims of fishermen have no basis. Beach sand mining has no role to play in fisheries, he says. "Fish breeds in estuaries but there are no perennial rivers draining into the sea in the region. The beach sand mined is naturally replenished and the claim of fishermen over disappearing fish varieties is irrelevant to beach sand mining," he argues.