Management responses to reconcile declining fisheries typically include closed areas and
times to fishing. This study evaluated this strategy for a beach clam fishery by testing the
hypothesis that changes in the densities and size compositions of clams from before to during
harvesting would differ between commercially fished and non-fished beaches. Sampling
was spatially stratified across the swash and dry sand habitats on each of two commercially
fished and two non-fished beaches, and temporally stratified across three six-week blocks:
before, early and late harvesting. Small-scale spatio-temporal variability in the densities and
sizes of clams was prevalent across both habitats and the components of variation were
generally greatest at the lowest levels examined. Despite this, differences in the densities
and sizes of clams among individual beaches were evident, but there were few significant
differences across the commercially fished versus non-fished beaches from before to during
harvesting. There was no evidence of reduced densities or truncated size compositions
of clams on fished compared to non-fished beaches, contrasting reports of some other
organisms in protected areas. This was probably due to a combination of factors, including
the current levels of commercial harvests, the movements and other local-scale responses
of clams to ecological processes acting independently across individual beaches. The
results identify the difficulties in detecting fishing-related impacts against inherent levels of
variability in clam populations. Nevertheless, continued experimental studies that test alternate
management arrangements may help refine and determine the most suitable strategies
for the sustainable harvesting of beach clams, ultimately enhancing the management
of sandy beaches.