Management of ecological perspectives of habitat mapping at Fire Island National Seashore

Abstract

In response to Hurricane Sandy, the National Park Service (NPS) has undertaken four submerged benthic habitat mapping projects in the Northeast Region of the U.S, including Fire Island National Seashore (FIIS) in New York. These studies represent the first comprehensive habitat mapping efforts undertaken by the NPS. The primary objective of these studies is to provide the NPS with a comprehensive baseline dataset of park submerged lands through the inventory, classification, and assessment of benthic resources and habitats developed through the integration of biological, geological, and physical data. With this enhanced, multi-disciplinary understanding of ecosystem structure and function within its parks, the NPS will promote resource stewardship and improve its capacity to initiate effective, scientifically sound management strategies. Mapping within FIIS is of particular interest because of the newly formed breachway created as a result of 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. The presentation will highlight several key components of the FIIS study that serve to demonstrate the value of habitat mapping from both management and ecological perspectives, including: The benthic habitat maps developed for study areas within FIIS. The map units were developed based on statistically significant relationships between the biological communities and the Geoform and Subform components of the Coastal and Marine Ecological Classification Standard (CMECS) - the national classification framework adopted by the Federal Geographic Data Committee; The effects of Hurricane Sandy on the habitats within FIIS and the surrounding area. Analyses found varying relationships between biological communities and geological and physical conditions that are believed to be based on the distance from the new breachway; Implications for management and the need for the establishment of a cost-effective monitoring program. While the findings from this study cannot be directly compared to pre-Hurricane Sandy conditions, there is sufficient evidence that the new breachway is having positive ecological effects. This is particularly the case within the area near the breachway, as demonstrated by the presence of mature blue mussels in dense concentrations and the emergence of seagrass beds; and The logistical challenges of mapping in very shallow and turbid waters. Water depths within FIIS average 1m and visibility is often less than 0.5m. Despite these conditions, full-coverage sidescan and partial-coverage bathymetry data was collected relatively rapidly using an EdgeTech 6205, which allowed as much as a 50m swath range in 2m of water. Ground-truth surveys were accomplished using grab samples and SPI imagery, since broader-coverage ground-truthing methods, such as underwater video and aerial imagery, were not possible.