Abstract: Reefs created by the eastern oyster Crassostrea virginica have supported significant fisheries for millennia, and small-scale oyster ‘picking’ remains a cultural tradition in many coastal areas. Despite the popularity of recreational fishing, the impacts of non-commercial harvest on marine ecosystems are poorly understood. Intertidal oysters serve as ecosystem engineers within otherwise soft-bottom estuaries but may be disproportionately susceptible to harvest because of their sessile nature and accessibility at low tide. We used a Before-After-Control-Impact design to investigate the effects of recreational oyster picking on the community of reef-associated mobile fauna. We deployed passive benthic sampling trays on eight reefs within the North Inlet estuary, South Carolina USA, and measured seven reef habitat metrics during both the ‘Before’ and ‘After’ harvest periods. Despite reductions in oyster density on harvested reefs following the fishing season, we did not observe changes in other biophysical properties of reefs (height, slope, rugosity, % shell cover, clump height, shell size). Similarly, we found variable impacts of oyster harvest on the community of reef-associated fauna, with only mean fauna body size and community diversity exhibiting clear impacts of oyster picking. While oyster harvest removes the physical structure provided by the target species, disturbance caused by recreational harvest in our study system apparently does not exceed the threshold which leads to cascading changes in the reef-associated faunal community. Given their role as ecosystem engineers, understanding the community-wide impacts of harvesting oysters is vital as managers move towards ecosystem-based management.
