A large-scale effort is underway to restore 13 miles of the Chandeleur Islands, and to improve long-term resiliency of the barrier island chain. The effort is co-led by the Louisiana Coastal Protection and Restoration Authority (CPRA), U.S. Fish and Wildlife Service (USFWS), and Louisiana Department of Wildlife and Fisheries (LDWF). A key goal is to restore and enhance seagrass meadows, however, uncertainties remain regarding the current distribution of seagrass and how that may change under proposed restoration projects. Decision-makers from USFWS, LDWF, and NOAA, together with the CPRA project manager and Breton National Wildlife Refuge resource manager, are collaborating with researchers from the University of Southern Mississippi, The Water Institute, and The University of Florida, to co-develop research that informs restoration design and adaptive management.

This presentation introduces an interdisciplinary framework that combines field observations, remote sensing, and numerical modeling to analyze seagrass dynamics at the Chandeleur Islands in support of restoration planning. The remote sensing component uses a deep learning model developed for this study, trained with field data to map seagrass extent and density from satellite imagery. Results are validated against historical maps, field observations, and aerial imagery. By mapping seagrass extent across multiple years, this approach allows evaluation of long-term trends as well as the impacts of individual tropical cyclones. The numerical modeling component uses a Delft3D FM coupled flow-wave model that explicitly represents the effects of seagrass on currents, waves, and sediment transport. The spatial extent of seagrass meadows in the model is based on the remote sensing-derived maps. By linking model results with remote sensing data, the study provides new insight into spatial and temporal changes in seagrass and the main factors influencing its survival.