Submerged Aquatic Vegetation (SAV)
SAV beds are an integral part of the aquatic environment. These beds serve coastal environments by reducing wave energy, stabilizing sediment, and provide nursery habitat for a variety of ecologically, recreationally, and commercially important fishes. Despite these benefits, SAV abundance is declining worldwide. Grand Bay NERR SAV monitoring began in 2003 in an effort to map the extent of the SAV beds and track seasonal changes in size and species composition. The two species that occur in the reserve are widgeon grass (Ruppia maritima) and shoal grass (Halodule wrightii), and are found extensively in the Pt. aux Chenes Bay and Middle Bay SAV beds. The Grand Bay NERR staff continues to monitor the SAV beds and compile data for analysis.
Invasive species are plants and animals that have been transported, usually by humans, from one area of the planet to another. Plants and animals in the new location are not adapted to living with the introduced species. Invasive species can cause harm to native ecosystems, reduce biodiversity and create negative impacts to the local economy. Grand Bay NERR invasive species monitoring efforts include: mapping species distribution before and after chemical and/or mechanical treatments, and identifying potential areas of infestation. Once an infestation is identified, the appropriate management action is applied if feasible. Some examples of invasive species found at the Grand Bay NERR are cogongrass (Imperata cylindrica), popcorn trees (Triadica sebifera), Chinese privet (Ligustrum sinense), feral hogs (Sus scrofa), and tilapia (Oreochromis nilocticus).
Since 2003 we have been monitoring erosion rates at various locations, which represent different underlying geological substrates and exposure to wave energy. The shoreline in areas exposed to high wave energy has been receding 6-10 m/yr. The erosion process is characterized by 2 phases. During low tides, the shoreline is undercut by breaking waves; during high tides, the undercut shoreline sloughs off in large sections and dissolves in the water. The long-term objectives of this project include analyzing seasonal variation in erosion rates and the impacts of hurricanes and tropical storms on coastal erosion. Click here to find out more about Shore Analysis.