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

Casas SM, La Peyre JL, La Peyre MK Evaluating variability and success in oyster reef restoration within an estuarine lake using two endpoints: Crassostrea virginica population dynamics and shell resources accretion. MEPS 524: 171-184


Restoration activities inherently depend on understanding the spatial and temporal variation in basic demographic rates of the species of interest. For species that modify and maintain their own habitat such as the eastern oyster, Crassostrea virginica, understanding demographic rates and their impacts on population and habitat success are crucially important to ensuring restoration success. We measured oyster recruitment, density, size distribution, biomass, mortality, and Perkinsus marinus infection intensity quarterly for 3 years on shallow intertidal reefs created with shell cultch in March 2009. All reefs were located within Sister Lake, LA. Reefs were placed in pairs at three different locations within the lake; pairs were placed in low energy and medium energy sites within each location. Restored reefs placed within close proximity experienced very different development trajectories; there was high inter-site and intra-annual variation in recruitment and mortality of oysters, with only slight variation in growth curves. Despite this high variation in population dynamics, all reefs supported dense (728 ± 102 ind m-2) oyster populations and high live oyster biomass (> 19.6 kg m-2) at the end of 3 years. Shell accretion, on average, exceeded estimated rates required to keep rate with local subsidence and shell loss. Variation in recruitment, growth and survival drive local site-specific population success and indicate a need to understand local water quality, hydrodynamics, and metapopulation dynamics when planning restoration.