METAL CONCENTRATIONS IN OYSTERS FROM THE SOUTHERN AFRICAN COAST

The aims of the general program to monitor marine pollution along the coast of South Africa are to discover and monitor sources of marine pollution, to establish coastal monitoring stations and to institute a national data center where all the information which is being collected can be collated most effectively. The results of recent laboratory experiments on the accumulation of nine elements have led to the belief that the Cape oyster Crassostrea margaritacea is a suitable indicator organism. This paper reports on a current survey of metal concentrations in C. margaritacea growing at 25 sites along a 500 km stretch of the South African coast, which was undertaken to provide data for the national marine pollution monitoring program and to supplement data from sediment and water sampling surveys of the estuaries in this region. Study materials, methods and results are discussed.