Historical Sediment Transport Pathways and Quantities for Determining an Operational Sediment Budget: Mississippi Sound Barrier Islands

Coastal Habitats of the Gulf of Mexico

“…Overall, shoreline recession is dominant throughout this portion of the GoM; however, beach nourishment since the 1970s has mitigated erosion hot spots, augmenting the littoral transport system and reducing erosion. Although sea-level rise for this section of coast is slightly greater than the eustatic rate (see Section 6.3.3.6), it has not caused significant shoreline recession during the period of record (Davis 2011a;Byrnes et al 2012). Based on geomorphic characteristics, shoreline change and longshore transport are summarized for three distinct areas of the northeastern GoM (Figure 6.42).…”

“…Although net longshore sand transport is to the east at about 100,000 m 3 /year (131,000 cy/year) along a short length of beach at the eastern end of this 300-km (186-mi) segment of coast (near Mexico Beach Inlet), net transport for the western 270 km (168 mi) of beach is to the west at rates between 115,000 and 400,000 m 3 /year (150,000 and 523,000 cy/year) (Dean and O'Brien 1987;Byrnes et al 2010). Seven inlets interrupt sand transport between Port St. Joe and Mobile Pass, and all but three are maintained by the U.S. Army Corps of Engineers, Mobile District.…”

“…Mobile Pass, Horn Island Pass, and Ship Island Pass are federally maintained navigation channels since the early 1900s (Byrnes et al 2010(Byrnes et al , 2012. Byrnes et al (2010) and Byrnes et al (2013) document long-term beach changes for the Mississippi Sound barrier islands, emphasizing the dominance of east-to-west longshore transport processes on erosion and deposition along the coast. Net shoreline recession of about Absalonsen and Dean (2010) and Miller et al (2004).…”

The Use of Aerial RGB Imagery and LIDAR in Comparing Ecological Habitats and Geomorphic Features on a Natural versus Man-Made Barrier Island

“…The island began formation in the 1960s from an underwater shoal created through the deposition of dredge material from the neighboring Pascagoula ship channel [12]. The island emerged around 1971 through channel maintenance and the natural reworking of the ebb-tidal sediment, combined with deposition from littoral drift [11,16,17]. Notably, among the islands in the chain, Sand has the highest elevation of approximately 9 m North American Vertical Datum 1988 (NAVD88).…”

“…It is composed mostly of quartz sand mixed with calcareous shell fragments. The island is geomorphically characterized by highly-elevated east-west recurved and truncated beach ridges [11,16]. As with East Ship, Sand has a stable core supporting a freshwater pond and vegetated habitats.…”