Gulf Coast Cooperative Ecosystem Studies Unit

Welcome to the Gulf Coast Cooperative Ecosystem Studies Unit. The GC-CESU facilitates collaborative research, education and technical assistance pertaining to the human and natural environment, within and beyond the region, among federal and state agencies, universities and non-governmental organizations.

Project Highlights

Blog

Comprehensive Marine Resources Survey at Naval Air Station Key West

Naval Air Station Key West (NASKW) is comprised of 6,249 acres of land distributed over 14 properties located in the Florida Keys. Several properties interface with the marine environment and include substantial coastal improvements including piers, seawalls, boat basins, dredged channels, and marinas. Protected marine resources, including corals, occur on and adjacent to these facilities. It is important to the US Navy to understand the type and extent of protected marine resources that occur on and adjacent to their facilities. Regulated marine resources (e.g., ESA-listed and unlisted corals, seagrass habitats, natural hardbottom habitats) that could impact the ability of the Navy to maintain, improve, or repair shoreside facilities were assessed at selected Navy locations following established data collection methods for marine assessments. Assessing these resources in terms of location, abundance, and vulnerability will assist the Navy in project planning and implementation, allowing an advance assessment of the potential extent of impacts, means of resource avoidance, and possible resource mitigation strategies where applicable. The assessment of corals included a complete accounting of all ESA-listed coral species encountered, and a more general assessment of non-listed corals focusing on documenting the distribution and abundance of non-listed corals with general density estimates.
Blog

Monitoring and Vegetation Management of Lower Keys Marsh Rabbit Populations - Naval Air Station Key West

Lower Keys marsh rabbits (LKMR, Sylvilagus palustris hefneri) are a federally endangered marsh rabbit subspecies endemic to the Lower Florida Keys. Much of the remaining population exists on Naval Air Station Key West (NASKW, Boca Chica, and Saddlebunch keys). NASKW conducts ongoing annual population monitoring for the LKMR as part of the Management Plan for LKMR and the NASKW Integrated Natural Resources Management Plan. The 2021 annual population monitoring occurred approximately 4 years post-Hurricane Irma. The patch occupancy (79%) and average patch pellet density (1.68 pellets/m2) were similar to 2016 pre-Hurricane Irma calculations. This evidence of robust rabbit populations can likely be attributed to the continued maintenance of habitat and the establishment of new breeding pairs. Overall, the 2021 patch occupancy and average pellet density represent a preservation of typical statistics.
Blog

Assessment and Review of Mussel-hydrologic Relationships for Mussels in East Texas

Freshwater mussels (Family: Unionidae) play important roles in freshwater ecosystems by facilitating nutrient cycling, increasing habitat heterogeneity, and serving as a food source for fishes, mammals, and birds. Due to their sensitivity to various environmental stressors, inability to escape human-mediated perturbations due to their limited mobility, and dependence on fishes to complete their life cycle, they are one of the most imperiled taxonomic groups in North America. In Texas, 15 of the 52 described species (29%) are listed as state threatened and two of these species, Pleurobema riddellii (Louisiana Pigtoe) and Potamilus amphichaenus (Texas Heelsplitter), are being considered for protection under the Endangered Species Act (ESA). However, the distribution of these species is still poorly known for some rivers within their presumptive ranges. This lack of information may hinder USFWS efforts to analyze the current and future viability of these two species through the Species Status Assessment (SSA) framework. The goal of this study is to provide high quality distribution information for P. riddellii and P. amphichaenus in select river systems within East Texas and Louisiana where they have been recently discovered or where their occupancy is suspected. Emphasis is being placed on surveying locations where additional information can help inform the SSA process for these species. The results gathered from this effort will help inform the listing process for these species and contribute to the knowledge base for mussel research in the southeastern United States. Comprehensive field surveys will be implemented in select rivers and streams in east Texas and western Louisiana to address knowledge gaps in the distribution and abundance of P. riddellii and P. amphichaenus. Putative identifications will be confirmed using a DNA barcoding approach. Historical data plus survey results from the present study we will used to develop conservation status assessment maps for P. riddellii and P. amphichaenus, which can be used to guide monitoring and recovery actions.