THE SUSCEPTIBILITY AND OR RESILIENCE OF ROCKY LITTORAL MOLLUSKS TO STOCK DEPLETION BY THE INDIGENOUS COASTAL PEOPLE OF TRANSKEI, SOUTHERN AFRICA

Coastal shell middens accumulated by indigenous people in the Nqabara/Human's Rock area of Transkei were analysed to obtain information on species and size preferences. These data are compared with analyses of middens resulting from a controlled exploitation experiment within the adjacent Dwesa Nature Reserve. Preferred prey items included the brown mussel Perna perna, the abalone Haliotis spadicea, the turban shell Turbo sarmaticus and various patellid limpets. Information on the life history characteristics and habitat preferences of these species has been used to predict whether or not a given shellfish population is likely to be susceptible or resilient to stock depletion as a result of traditional gathering practices. Perna perna and Patella oculus appeared to be the species most susceptible to depletion. Despite the impoverished state of exploited populations there appears to be no evidence of recruitment failure. The persistence of these stocks is probably dependent on reproductive output from exploited populations and on larval immigration from adjacent refuge populations. Provided there is no change in gathering methodology, adequate replenishment of these stocks should be maintained.