• Land Acquisition
•   Current Projects
  • Natural Resource Monitoring
    • SAV
    • Erosion
    • Ecological Recovery
    • Katrina-Before and After
  • Natural Resource Management
    • Invasive Species
    • Prescribed Fire
    • Other Techniques
  • Restoration
    • Oysters
    • Marsh Vegetation
    • Pine Savanna

Natural Resource Monitoring

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Monitoring projects at Grand Bay NERR include:

Submerged Aquatic Vegetation (SAV)

SAV beds are an important part of the aquatic environment; these beds benefit the shallow waters of coastal environments by reducing wave energy, stabilizing sediment, and providing nursery habitat for commercial and recreational fish species. Despite these benefits, SAV is declining along the coast of the Gulf of Mexico and worldwide. Since 2003, we have been monitoring the SAV resource of Grand Bay NERR by mapping the extent of SAV beds and tracking seasonal changes in the size and species composition of the seagrass beds. The most extensive SAV beds occur in Middle Bay and Pt. aux Chenes Bay.

After baseline data have been collected, we can assess the feasibility and need to restore SAV beds to areas that can support them.

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Erosion

Grand Bay NERR encompasses a retrograding delta. The Pascagoula River historically flowed through the area, but since the river migrated west, sediment input has declined drastically. Without sediment deposition from a river, wave action from the Mississippi Sound is eroding the shoreline. Knowledge of erosion rates at locations around the NERR could benefit projects occurring in this area. Potential projects that could incorporate erosion data might include shoreline restoration projects, habitat improvements, and research into techniques to abate erosion along the coast. In addition, boat traffic along the bayous, especially near boat ramps, may be exacerbating erosion in some areas.

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.

Shoreline erosion occurs as large pieces of vegetation
and sediment are undercut, then break away.

A shoreline erosion transect.

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Vegetation Recovery after Extreme Weather

This project will monitor the recovery of vegetation in habitat types of interest (shell middens, pine hammocks, marsh, etc.) after extreme weather events. Most habitats were affected little by Hurricane Katrina. The notable exceptions were the .island. features (i.e., middens, hammocks) of the reserve. All plants on these islands displayed signs of damage (e.g., broken stems) and stress (e.g., brown foliage). While some plants showed signs of recovery during the fall of 2005, we will begin monitoring vegetation during the spring of 2006 to assess the full extent of the storm.s impact. As additional hurricanes and tropical storms occur, we will monitor both the effect of severe weather on vegetation communities and the recovery of vegetation following the storms.

Vegetation on a shell midden before (left) and after (right) Hurricane Katrina.

 

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