Presence of a common predator, Sheepshead (Archosargus probatocephalus), affects survival of Eastern Oyster (Crassostrea virginica) in an experimental setting
Description
Oyster reefs are a vital but declining component of nearshore, estuarine ecosystems. Global efforts to restore this important habitat are ongoing but have had varied success. The potential for biotic factors such as predation to influence restoration trajectories is rarely considered; however, there is mounting evidence that a better understanding of trophic relationships could aid in the restoration of the ecologically critical Eastern oyster (Crassostrea virginica). A common predator-prey interaction within the oyster reef community was examined through manipulative experiments to determine what effect predator presence had on early survivorship of oysters – a factos known to influence success of oyster reef restoration. The stone crab (Menippe spp.) is a known predator of spat (<30 mm) and juvenile (30 mm-75 mm) sized Eastern oysters but also serves as prey for more mobile predatory fish. Sheepshead (Archosargus probatocephalus), a fish with a diet high in structure-associated invertebrates, are one of many predatory fishes that utilize oyster reefs. Sheepshead presence was found to significantly increase juvenile oyster survival through reduction in stone crab abundance. The mechanism was primarily trait-mediated interactions (i.e. behavioral or indirect effects) although evidence for density-mediated reduction was also present. These results suggest that changes in abundance of an exploited finfish species can influence juvenile oyster survivorship and hence performance of oyster restoration efforts.