Monday, November 13, 2006 - 1:00 PM

Fine-Scale Subaqueous Soil Survey of a Created Seagrass Mitigation Site.

Kelly Fischler1, Mary Collins1, Larry Ellis1, and Wade Hurt2. (1) Univ of Florida, 2169 McCarty Hall, Gainesville, FL 32611, (2) USDA/NRCS, 2169 McCarty Hall, Gainesville, FL 32611

Seagrasses in the Indian River Lagoon, FL provide an ecological foundation for benthic food webs and in turn, support millions of dollars in commercial and sports fisheries.  Increases in coastal development, however, have led to new methods in seagrass management.  Recent mitigation efforts involved the transformation of a spoil island (SL 15) into a potential habitat for seagrasses.  After most of the interior of the island was removed, a submerged habitat was created.  However, the vertically undulating bottom in this area has influenced the accumulation of algae and fine sediments which might be significant for future seagrass growth.  A fine-scale subaqueous soil map and digital elevation model (DEM), therefore, would be of importance in order to understand how these factors may affect the project’s degree of success.  Water depths and ground cover were intensively measured within SL 15 and corrected for tides. Soil samples were analyzed for particle size distribution and organic matter content.  Using geostatistics in a GIS, these parameters were interpolated to create map layers.  A final soil survey was created by delineating the DEM into landscape units based on elevation, vegetation and soil properties.