Cooperative Fish and Wildlife Research Units Program: Louisiana
Education, Research and Technical Assistance for Managing Our Natural Resources

Lavaud R, La Peyre MK et al. 2023. Final Project Report: A roadmap for developing resilient coastal shellfish populations: using spatial and process-based modeling for restoration under current and predicted future water quality conditions. DOI Climate Adaptation Center FInal Report.


Our estuaries support valuable recreation, fisheries and aquaculture dependent on healthy and vibrant ecosystems. Along the northern Gulf of Mexico (nGoM), estuaries sustain local economies through their high productivity. At the same time, they receive over 50% of the US watershed discharge, and water quality within these estuaries is impacted by local management of rivers, and climate change. Within nGoM estuaries, eastern oysters serve as both critical fisheries, and ecosystem engineers, providing nursery and feeding grounds, and improving water quality. Recent declines in oyster populations from anthropogenic activities and extreme events have led to significant efforts to restore wild, self-sustaining broodstock reefs, and develop aquaculture. In this project we extended a model predicting oyster survival, growth and reproduction across 6 important oyster growing estuaries in Texas and Louisiana. We used this model to provide restoration and aquaculture suitability scores within the coastal waters to help inform managers and the oyster industry. The resulting suitability scores reflect likelihood of oyster survival and reproduction (restoration) and likelihood of oyster growth and survival (aquaculture) under current and future (2041-2050) conditions. Louisiana estuaries showed higher growth rates and reproduction than Texas estuaries, but due to the higher variability and more frequent extremes in salinity and temperature, Louisiana estuaries were more likely to experience mortal conditions. Comparison between current and future conditions indicated that oyster aquaculture and restoration potential in presently occupied areas might decrease in the future; however, the spatial resolution of currently available climate model outputs within coastal and estuarine areas limits planning information. These suitability maps help managers and stakeholders assess the current and future value of specific locations for oyster restoration and aquaculture. This work also identifies the need for improved within-estuary water quality projections and highlights the need to continue to quantify oyster responses to extreme and novel conditions.