SEAFLOOR HABITAT MAPPING IN EASTERN LONG ISLAND SOUND

The aim of the Long Island Sound Cable Fund, established by the states of Connecticut and New York is to: “Emphasize benthic mapping as a priority need, essential to an improved scientific basis for management and mitigation decisions.” Following the establishment of the fund several workshops and a survey identified the most critical data gaps and areas needing mapping in the Sound. Three multidisciplinary teams were identified to conduct a Phase I Pilot Project mapping effort in 2012-2013 focused on central Long Island Sound that produced a comprehensive Final Report in 2015.

Phase II began in 2017 focused on eastern Long Island Sound from west of the Connecticut River to Fishers Island Sound with 90 sites selected based upon image analysis of the acoustic backscatter data collected by NOAA that identified large (km²) to meso-scale (100m²) seafloor landscape patches. Sites were selected to ensure representation of existing physical bottom types and regions of geological (and potential ecological) transitions. Ecological, geological and physical oceanographic data were collected and are being integrated to create seafloor habitat maps, estimate spatial distributions of ecological communities, and identify regions of high biodiversity. Ecological characterization comprised video and photographic transects as well as grab samples collected using the USGS’ SEABOSS, and UConn’s Kraken2 ROV during three cruises in the Fall, 2017 and Spring, 2018. Digital still images, standard and high definition video and sediment grabs are currently being analyzed for infauna and epifauna. In addition shallow water SCUBA diving provided imagery and suction samples of cryptic taxa in areas with hard substrates.

For Phase I eCognition software was used to analyze the acoustic backscatter data to extract six primary landscape features or classes. Additional geological, ecological and physical data were integrated into these classes to generate comprehensive habitat maps. These protocols are currently being applied to data from the Phase II area to generate similar map products to inform marine spatial planning and management for multiple uses of the Sound’s environment.