Coastal dune sustainability: understanding dune morphology, stabilization, and erosion in the face of Superstorm Sandy
Bianca M. Reo
Department of Biology, Villanova University, Villanova, PA
Department of Biology, University of Pennsylvania, Philadelphia, PA
Leidy Labs, 3740 Hamilton Walk, Philadelphia PA 19104
BReo@sas.upenn.edu (973)879-2856
Bianca is currently a 1 st year PhD student at the University of Pennsylvania. Prior to beginning her program at UPenn she attained a BS in Biology at Villanova University and did her undergraduate studies at Princeton University in Ecology and Environmental
Studies. She is an avid beach lover from northern NJ. Thus, when Superstorm Sandy devastated the northeast she sought ways to give back to her state by getting into the field to conduct research geared at conservation with the aim of making us better prepared for the next storm.
Abstract
Worldwide, coastal areas are some of the most densely populated localities, despite their inherent geological instability and high vulnerability to the effects of climate change. Coastal dunes are the best option to buffer these localities and paramount to creating and maintaining safe, well-fortified coastlines. In 2012, Superstorm Sandy devastated the northeast US and presented an opportunity to examine how NJ’s largest continuous natural dune system responded to a major stochastic event. At Island Beach
State Park, we quantified coastal dune erosion from Superstorm Sandy as a factor of pre-
Sandy beach characteristics: dune height, beach width, and the dominant plant species stabilizing the primary dune, native Ammophila breviligulata or invasive Carex kobomugi . We assessed erosion using a combination of GIS analyses of pre- and post-
Sandy aerial images and GPS mapping of vegetation distributions and analyzed our data in a multilevel nested model. Dune loss from Superstorm Sandy varied based on the dominant species fronting the dune: native A. breviligulata or invasive C. kobomugi .
Dunes fronted by C. kobomugi were better stabilized and thereby suffered less erosion from Sandy. There were differences in the beach widths between the dunes occupied by the different species and the water, and this may account for some differences in dune morphology. However, beach width was not a confounding factor in our analyses examining how erosion differed with the two species. Although C. kobomugi is known to reduce native diversity and abundance, the species may be beneficial for coastal protection. These findings are contrary to past anecdotal notions that dunes stabilized by
C. kobomugi were more prone to breaching. Dunes are and will continue to be our most economical and most natural form of coastal defense. This study highlights factors that contribute to quantifying and improving dune sustainability and the lessons learned here from Superstorm Sandy have important applied implications management decisions.