Coastal shellfish resource use in the Quirimba Archipelago, Mozambique

The level, types, and influences of use of intertidal and subtidal molluscs and crustaceans were examined on four islands of the Quirimba Archipelago in northern Mozambique. Artisanal collecting was restricted to spring low tidal periods and involved at least 5% of the population of the study islands. Twenty-two mollusc species and five decapod crustascean species (Palinuridae and Portunidae) were collected, of which the large gastropods Chicoreus ramosus (Muricidae) and Fasciola trapezium (fasciolaridae), were the most important on coral reef rubble shore regions. The bivalves Pinctada nigra and Barbatia fusca were the most important species in seagrass (Halhodule sp, and Cymodocea sp.) areas. The diversity and identity of target species and proportions of species taken by intertidal collectors differed between study islands. The mean length of the gastropods C. ramosus and F. trapezium collected on the larger islands of Quirimba and Quisiva have significantly decreased on the basis of examinations of previously collected middens. Those collected at Quirimba and Quisiva Islands were also smaller than current collections at the nearby smaller islands of Quilaluia and Sencar.