Evaluating Ecosystem effects of oyster restoration in the Mississippi Sound

Oyster reefs along the northern Gulf of Mexico are primarily formed by the eastern oyster, Crassostrea virginica, and are among the few biogenic natural habitats in the region. The increasing awareness of ecosystem services that habitat-forming bivalves provide, and the decline of the native species’ population has led to a myriad of restoration efforts which have yielded varying results. Successful reef restoration efforts requires a deeper understanding of how variations in the timing and scales of environmental stressors control the survival, growth, and recruitment of reef associated species like oysters, shrimps, pelagic and benthic fish species. A modeling approach has been designed for exploring optimal growth conditions for oysters, studying the effect of seasonal trends in environmental stressors on the growth and survival of reef-associated species, and performing scenario testing for alternative restoration plans in the Mississippi Sound. The model uses a carbon budget approach, accounts for different functional groups within the trophic network on the reef, and operates on daily temporal resolution. Preliminary results indicate that restoration efforts may maximize benefits from the interactions between different salinity regimes and growth as well as mortality of oysters at three different class sizes of sacks, seeds, and spats. The study also seeks to evaluate the effects of different restoration efforts on promotion and recruitments in oyster populations as well as other reef-associated fishes and invertebrates. The current capabilities of the model can be scaled up to include evaluating changes in ecosystem goods and assessing their contributions to human well-being, the results of which will inform management decisions.

Keywords: ecosystem modeling, oyster ecology, ecosystem-based management.