Exploitation of molluscan shell deposits in Vigai estuary at Athankarai

Abstract

Molluscan shell deposits are present in the bed of Vaigai estuary at Athankarai, on the southeast coast of India, which are being exploited intensively since 1978. The topographical and environmental features of the estuary, distribution and species composition of shell deposits, extent of resources, methods of exploitation, magnitude of production and utilization have been studied The shell deposits are distributed In the bed of estuary over a distance of,4.63 km in the upper portion of the estuary. They are sub fossil deposits 0 15 m-0.46 m In thickness and comprise predominantly of Meretrix casta vyhichare favoured as raw material in the manufacture of calcium carbide and In tannery Industry. Shells of other species in the deposits like Cerithidea fluviatilis, Hemifusus cochlidium,- Area; Paphia ate. are convarteci into lim^. The annual production of lime shells from the estuary Is about 5.500 t. The removal of large numbers of live adults and seed clams of Meretrix casta present In the upper layer of sediment along with the sub fossil shells Is pointed, out and the need for preventing the destruction of live shellfish is stressed,