Effects of shoreline development and freshwater discharge on nekton assemblage and trophic structure in a northern Gulf of Mexico estuary
Date of Award
Master of Science (MS)
Ocean Science and Engineering
Dr. Kevin Dillon
Committee Member 2
Dr. Michael Andres
Committee Member 3
Dr. Mark Peterson
Coastal salt marshes support a diversity of nekton and facilitate critical ecosystem functions but are threatened by shoreline development and climate change. Therefore, coastal ecosystem managers have begun incentivizing the use of living shorelines (LS), erosion control structures incorporating native plantings, to mitigate ecological consequences of marsh loss. However, post-restoration climate changes may shift habitat templates and negate positive effects of ecosystem restoration. I evaluated the ecology nekton along LS, natural marshes, hardened shorelines and greyed shorelines within Biloxi Bay, Mississippi, during a high freshwater discharge (HFD) period by comparing nekton assemblage (using species richness, Shannon-Wiener diversity, and relative abundance), trophic structure (using physical diets and stable isotope analysis), and their responses to abiotic shifts along an estuarine gradient. Overall, I noted a decrease in richness and diversity during HFD and a more homogenous nekton assemblage along the estuarine gradient. No benefit to nekton assemblage was detected along LS, although habitat type was broadly less influential in predicting the relative abundance of common nekton during HFD. Although trophic structure varied by season and estuary position, organisms along natural marshes showed more dependence on benthic and intertidal resources whereas LS functioned intermediately between natural marshes and developed shorelines. This study will help managers to further understand the efficacy of LS in areas prone to frequent disturbance or climate change, and calls attention to important considerations when implementing a LS that may serve to improve monitoring efforts and furthers our understanding of the efficacy of this restoration strategy.
Schumacher, Glenn, "Effects of shoreline development and freshwater discharge on nekton assemblage and trophic structure in a northern Gulf of Mexico estuary" (2022). Master's Theses. 921.
Available for download on Thursday, July 13, 2023