Submerged marine habitat mapping at Fire Island National Seashore: A post-hurricane Sandy study

LaFrance Bartley, Monique; King, John; Oakley, Bryan; Caccioppoli, Brian

In response to Hurricane Sandy in 2012, the National Park Service (NPS) provided funding for four submerged seafloor habitat mapping projects in the northeast region of the United States, including Fire Island National Seashore (FIIS) in New York. After the storm, it became evident that, unlike its terrestrial lands, there was a clear lack of fundamental information regarding the majority of NPS submerged lands, including the resources and habitats that exist and their overall condition. Consequently, it was not possible for NPS to fully assess the effects of Hurricane Sandy on its submerged holdings or anticipate future changes. Previous NPS mapping studies across the United States have been limited in scope and purpose, primarily performed at the pilot-scale to demonstrate feasibility and largely focused on the geological component of habitat mapping, with less consideration given to the biological component and the interaction between the two. These four post-Hurricane Sandy studies, conducted at FIIS, Cape Cod National Seashore, Assateague Island National Seashore, and Gateway National Recreation Area, represent the first comprehensive habitat mapping efforts undertaken by NPS and will serve to guide future efforts. The knowledge gained from these studies will allow NPS to promote resource stewardship; improve its capacity to initiate effective and scientifically sound management strategies; and better understand and anticipate future changes, such as those due to natural processes, global climate change, resource extraction, land-use impacts, and other human activities. To implement effective management strategies, agencies require a multi-disciplinary understanding of ecosystem structure and function. As such, the primary objective of this mapping study was to provide NPS with a detailed baseline understanding of benthic resources and habitats for portions of FIIS through the integration, assessment, and classification of biological, geological, and physical data. Benthic habitat mapping of FIIS was of particular interest to NPS because of the newly formed breachway created by Hurricane Sandy, which bisects the sand barrier island separating FIIS from the ocean. The breachway has led to an influx in ocean water, consequently altering the conditions of the shallow bay environment and the associated biological communities. Three study areas located at varying distances from the new breachway were identified within and adjoining the boundary of FIIS within Great South Bay in collaboration with NPS staff: Otis Pike High Dunes Wilderness Area, Sunken Forest, and the area adjacent to the eastern portion of the new breachway (referred to as “East Breach”). Multiple datasets were collected within these study areas during the summer and early fall of 2014 and 2015, including sidescan, bathymetry, sediment profile imagery (SPI), and sediment and macrofauna grab samples. Aerial imagery openly available was also used to assist in analyses. For Otis Pike and Sunken Forest, these datasets were integrated to develop maps of seafloor habitats (referred to as “biotopes”) that represent statistically significant relationships between macrofaunal communities and their associated geological and sedimentary environment. For the East Breach study area, a biotope map was not developed, rather the data were examined for exploratory purposes and to identify potential changes since Hurricane Sandy. The resulting biotope maps for Otis Pike and Sunken Forest indicate the areas are primarily defined by sand waves, sand dunes, sand flats, and basins comprised of medium and coarse grain sand. Biologically, these biotopes are dominated by several species of macrofauna, including the polychaete worms Owenia fusiformis, Polygordius jouinae; the small bivalves Gemma gemma and Mulinia lateralis; the amphipod Ampelisca verrilli and nematode worms.

Submerged marine habitat mapping at Fire Island National Seashore: A post-hurricane Sandy study

Series

See also

Collections