Heavy metal levels in the sediments of four Dar es Salaam mangroves. Accumulation in, and effect on the morphology of the periwinkle, Littoraria scabra (Mollusca: Gastropoda).

Heavy metals were determined in the soft tissue and shells of the littorinid, Littoraria scabra, and in the sediments of four mangrove areas along the Dar es Salaam coastline where L. scabra was collected. Several metals accumulate, preferentially in the animals' soft body parts, but do not seem to affect the shell morphology of this species.