Survey and Assessment of Benthic Habitat for Offshore Wind Development
In support of researchers at UNC-CH’s Institute for Marine Science and NOAA’s Center for Coastal Fisheries Habitat Research, Geodynamics developed and conducted preliminary seafloor surveys using sidescan and multibeam sonar. The survey design balanced the need for appropriate sediment characterization and target identification with constraints to available shiptime and a limited budget. Geodynamics oversaw all hydrographic operations, including 2700 line miles of full coverage (110%) sidescan sonar using an EdgeTech 4200 and ‘skunk stripe’ multibeam collection using a Reson 7125, both paired with an Applanix POS-MV inertial navigation system. Data derived from this study provided not only real presence/absence information on hard-bottom and cultural resources in Call Area Wilmington-East, but also established baseline data for use in future monitoring efforts.
Geodynamics staff supervised all hydrographic operations aboard the NOAA research vessel Nancy Foster for surveys over a 437mi2 area. This 18 day survey of 24h operations produced a massive amount of sidescan sonar data; Geodynamics was tasked with digitizing all sidescan data and classifying seabed polygons based on ground truthing to create attributed GIS layers that would support NOAA/UNC/BOEM’s multi-disciplinary assessment of the distribution of hard bottom areas and Essential Fish Habitat. In addition to simply providing target identification coordinates for potential shipwrecks and cultural resources, Geodynamics GIS staff sought to support habitat modeling efforts through a carefully designed GIS deliverable that would efficiently support these researchers’ varying scales of interest and data requirements. Geodynamics built a mosaic dataset to manage a collection of rasterized sidescan datasets stored as a catalog and viewed as a mosaicked image to support researchers’ varying scales of interest through a product that was manageable, quick to load, scalable, and easy to manipulate.