Submerged Aquatic Vegetation (SAV) Aerial Hyperspectral Imaging and Groundtruthing Survey: Use of Aerial Hyperspectral Imaging in Defining Habitat Areas of Particular-Concern for Summer Flounder in a High-Energy Estuarine Environment

Abstract

European Network for Social and Economic Research (ENSR) in conjunction with Spectrum Mapping LLC, and Barry Vittor and Associates, conducted an SAV Aerial Hyperspectral Imaging and Groundtruthing Survey within Manahawkin Bay, Ocean County, New Jersey in July 2002. The survey was performed to finalize location of a proposed, submerged transmission line within a pre-existing right-of-way (ROW), and identify and avoid SAV beds and areas defined as Habitat-Areas of Particular-Concern (HAPC) for summer flounder (Paralycthes dentatus). An AISA (Airborne Imaging Spectrometer for Applications) hyperspectral imaging sensor was used to determine presence/absence of SAV beds within a 3.75 sq. mile area; give precise location and extent of identified SAV beds; and calculate percent coverage of identified SAV per meter of each survey site within and adjacent to the proposed submerged cable project. Conventional groundtruthing/field verification methodologies used in Florida, Chesapeake Bay, and New Jersey, were combined and modified to increase survey accuracy, increase field efficiency, and provide sufficient data for hyperspectral analysis/verification. Additional groundtruthing data collected at each survey site included: substrate type; vegetation composition; relative health of SAV; blade lengths; random stem counts; presence of hard clam (Mercenaria mercenaria); and water quality. In addition to the hyperspectral survey, a Braun-Blanquet and hydrographic survey was conducted by Crofton Diving Industries to confirm and further validate hyperspectral results and determine proximity of potential unvegetated SAV habitat to proposed project location.