Moderate recreational oyster harvest has variable impacts on biophysical properties of reefs and reef‐associated fauna

Abstract

Despite the popularity of recreational fishing, our understanding of the impacts of this type of harvest within marine ecosystems generally lags behind the well‐documented effects of commercial fisheries. 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 physical structure provided by reefs and the community of reef‐associated mobile fauna. Despite reductions in oyster density on harvested reefs following the fishing season, we did not observe changes in other biophysical properties of reefs. Similarly, we found variable impacts of oyster harvest on the community of reef‐associated fauna, with community diversity changing seasonally on closed reefs but remaining low throughout on harvested reefs. Direct relationships between change in oyster density through time and changes in reef rugosity, faunal diversity, and faunal density were also variable. While oyster harvest removes the physical structure provided by these foundation species, the level of recreational harvest currently occurring in our study system apparently does not exceed the threshold which leads to cascading changes in reef‐associated fauna.