Date of Award

Fall 12-2016

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Marine Science

Committee Chair

Dr. Davin Wallace

Committee Chair Department

Marine Science

Committee Member 2

Dr. Maarten Buijsman

Committee Member 2 Department

Marine Science

Committee Member 3

Dr. Troy Pierce

Abstract

The Mississippi – Alabama barrier island chain is experiencing accelerated sea level rise, decreased sediment supply, and frequent hurricane impacts. These three factors drive unprecedented rates of morphology change and ecosystem reduction. All islands in the chain have experienced land loss on the order of hectares per year since records began in the 1840s. In 1969, Hurricane Camille impacted as a Category 5, breaching Ship Island, and significantly reduced viable seagrass habitat. Hurricane Katrina impacted as a Category 3 in 2005, further widening Camille Cut. To better understand the sustainability of these important islands and the ecosystems they support, sediment transport dynamics must be quantified. In this study, four LiDAR datasets are used to investigate both subaerial and subaqueous volume changes during the most recent intense storm impact, Katrina, and the fair-weather period following. During the Katrina event, sediment comparable to 1.5 times the 2004 subaerial island volume was lost from the topo/bathy system. Only 1/5 of this volume was recovered between 2007 and 2010. The island returned to a net sediment loss between 2010 and 2012, although island area continued to increase. This highlights the importance of full topo/bathy datasets for morphodynamic analyses of barrier island systems. Seagrass patches around the island are primarily limited by exposure to wave energy, but are also limited by depth and rapid deposition events. Area and volume trends indicate seagrass habitat will not naturally increase, but a Camille Cut restoration may increase habitable area for seagrass if overwash processes are limited.

ORCID ID

orcid.org/0000-0001-5215-2063