GSA Connects 2024 Meeting in Anaheim, California

Paper No. 191-4
Presentation Time: 8:00 AM-5:30 PM

ASSESSING CHANGES TO SEDIMENT TRANSPORT, FORAMINIFERA, AND SEABED MORPHOLOGY RELATED TO A COASTAL SHORELINE STABILIZATION PROJECT: SUGARLOAF ISLAND, NC


MALOSKY, Kristen, MALLINSON, David and CULVER, Stephen, Department of Geological Sciences, East Carolina University, East 5th Street, Graham Building 101, Greenville, NC 27834

Sugarloaf Island is a spoil island within Bogue Sound, off the coast of Morehead City, NC. It acts as a fetch-limited barrier island, protecting the mainland from wind and wave energy erosion. Currently, the shoreline of Sugarloaf Island is eroding, making it the focus of a shoreline stabilization project consisting of wave attenuation devices (WADs), subaquatic vegetation (SAV, i.e., coastal seagrass), oyster reefs, and a rock revetment. Foraminifera species distribution, sediment characteristics, and seabed morphology are being mapped to provide information on sediment sources and transport, erosion patterns, and storm impacts. In total, 40 samples were collected offshore and on the beaches prior to the emplacement of the stabilization structures. Side-scan sonar data (450 kHz) were acquired to produce a mosaic that is being analyzed for seabed morphology and acoustic backscatter data to be correlated with grain size characteristics. Sediment samples analyzed thus far are generally moderately to well-sorted and consist of very fine to fine, slightly gravelly sand. Living (stained) foraminifera are being identified alongside the dead modern and fossilized specimens. The foraminifera identified thus far are mainly benthic, with occasional planktonics, and with several percent fossilized foraminifera on a spit located west of the island. These samples provide a baseline data set that will be compared to a second set to be collected in Fall 2024 after the stabilization structures have been completed. More in-depth statistical analysis of the foraminiferal assemblages, sediment characteristics, and side-scan sonar analysis are in progress and will be presented.