Project:

Survey and Assessment of Benthic Habitat for Offshore Wind Development

client

UNC Chapel Hill Institute for Marine Sciences

location

Call Area Wilmington-East, NC

services

Hydrographic,Geophysical, GIS

summary

Designed and executed sidescan and multibeam sonar survey to cost effectively characterize the seafloor in 437 mi2 call area, then classified seabed types to create attributed GIS layers for analysis.

partners

NOAA Center for Coastal Habitat and Fisheries Research

description

Geodynamics was contracted to assess and characterize the seafloor in support of researchers at UNC-CH’s Institute for Marine Science and NOAA’s Center for Coastal Fisheries Habitat Research. Geodynamics developed a detailed survey plan to conduct preliminary environmental site characterizations using sidescan and multibeam sonar. The survey design balanced the need for appropriate sediment characterization and target identification with constraints to available shiptime, a limited budget, and a requirement for immediate data turnaround.

The survey efficiently mapped 437mi2 of seafloor in BOEM Call Area Wilmington-East off Cape Fear, NC aboard the NOAA research vessel Nancy Foster. 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. This survey plan was designed to provide the most cost effective means to determine the location of hard-bottom zones and areas devoid of hard-bottom; acquisition and processing were completed according to NOAA Hydrographic Specifications & Deliverables and the IHO Standards.

Data derived from this study will not only provide real presence/absence information on hard-bottom and cultural resources in Call Area Wilmington-East, but will also establish baseline data for use in future monitoring efforts. Geodynamics digitized all sidescan data and classified seabed polygons based on ground truthing to create attributed GIS layers. Sidescan mosaics and seafloor bathymetry grids were then integrated into GIS with FGDC compliant metadata with final QA/QC and analysis.