Estimation of Low Frequency Scattering from Fish Schools on the Continental Shelf off New Jersey
Abstract
The GeoClutter 2001 (GCOi) experiment conducted on the continental shelf of New Jersey in April and May 2001 focused on physical mechanisms causing geologically produced acoustic clutter and false targets around 400 Hz. During OCOl, a large, strong unidentified target was detected. In May 2001, backscatter measurements from the ocean volume were made in the same area at 2 to 10kHz and at 38kHz to examine scattering from fish during the Boundary Characterization (BCOl) experiment. Also, the National Marine Fisheries Service (NMFS) conducted a trawl and 38 kHz echosounder fisheries survey in the region from February to April 2001. Data from BCOl and NMFS show that large demersal and pelagic fish schools occur on the New Jersey shelf in spring. Demersal schools are most likely composed of scup, seabass, hake, or dogfish shark. Pelagic schools are probably composed of herring-like fish or butterfish. Results of modeling backscatter from these species indicate that these schools could produce significant scattering at 400 Hz and could have easily produced the large unidentified target observed during GC0l.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 10, 2003
- Accession Number
- ADA418444
Entities
People
- Redwood W. Nero
- Richard H. Love
Organizations
- United States Naval Research Laboratory