The Aquatic Resource Management team provides stewardship to the vast estuaries and the salt marsh and mangrove habitats within the reserve, as well as the portion of the marine habitat that falls within the reserve’s boundary. This team includes the Northeast Florida Aquatic Preserves staff.
Shoreline erosion along the banks of the Intracoastal Waterway has been identified as an ongoing issue within the GTM Research Reserve. Storm surges and increased waves due to boat wakes threaten the stability of the shorelines and the edges of the marsh. In response to these threats, experimental gabions were placed in the subtidal zone in order to dissipate wave energy before it hits the shoreline. This project is done in conjunction with Coastal Engineers from University of Florida. Wave energy and sediment composition are being monitored in these areas to determine the effectiveness of the gabions and this data will be used to advise a larger scale installation of gabions next year.
Oyster Shell Recycling
Oyster health is in decline worldwide. It is estimated that oyster populations have been reduced by 85% globally. Oysters are a keystone species within the estuarine ecosystem and provide a number of critical ecosystem services such as filtering nutrients from the water column, food for shorebirds and marine animals, reefs are habitat for numerous fish and marine invertebrates, and oyster reefs also break up wave energy that would otherwise contribute to marsh or shoreline erosion.
The Aquatic Preserve has an oyster reef restoration project on Wright’s Landing on the peninsula of the GTM Research Reserve. Here, in 2012, thirty eight oyster reefs were installed by GTM Research Reserve volunteers. These reefs were constructed with bagged oyster shell collected from local restaurants as part of the oyster shell recycling program. Each reef is 20 ft. long and approximately 3 ft. high. Oyster spat settled on the loose shell and over time, the reefs became encrusted with live oysters. Monitoring has been conducted on these reefs and has shown that biodiversity has significantly increased around the reefs.
Spartina Transplant and Restoration (STAR)
Spartina alterniflora (Smooth cordgrass) is the dominant vegetation in the low marsh areas within the GTM Research Reserve. When conditions in the marsh lead to erosion, the Spartina is lost, which continues a cycle of shoreline loss. Transplanting Spartina plugs aids in the recovery of impacted areas and facilitates a more rapid recolonization of the vegetation community.
Plugs of Spartina are harvested from healthy donor marsh within the reserve and planted behind shoreline restoration treatments. The roots and rhizomes of the Spartina bind the soil in place, preventing further erosion. Furthermore, the vegetative portion of the plant dissipates wave energy and encourages the accretion of additional sediments, resulting in greater resiliency of the marsh.
In addition to using Spartina plugs for restoration, the STAR program incorporates a research component to determine best management practices for Spartina harvest. A study was conducted which examined six different harvest intensities from no harvest to 100% harvest, and the rate of marsh recovery was determined for each harvest treatment. This information is being used to advise harvest practices for restoration professionals.