The Potential Impact of Human Gathering on Shellfish Populations, with Reference to Some NE Australian Intertidal Flats

Abstract

Sampling of the intertidal flats at two localities on the south eastern side of Moreton Bay, Queensland revealed a diverse macromolluscan fauna which included moderate densities of several large species common in Aboriginal shell middens of eastern and northern Australia. The potential impact of traditional shell-gathering on these species is investigated by means of an approach which uses life-history and habitat information to predict a priori whether a given local intertidal population would be susceptible to depletion when exploited in this manner. The attributes of size at maturity, intertidal burying, subtidal distribution, benthic mobility, and duration of pelagic larval phase are assessed by means of field observation and literature review for species of Anadara, Saccostrea, Pyrazus, Strombus, and venerid bivalves. This assessment leads to predictions of low resilience to depletion by traditional shell-gathering for Saccostrea and Pyrazus, but high resilience to depletion by traditional shell-gathering for Saccostrea and Pyrazus, but high resilience for the others. We also discuss some corroborative data and the implications of other modes of exploitation.