Consecutive Acoustic Observations of an Atlantic Herring School in the Northwest Atlantic
Abstract
Several successive images of the same school of Atlantic herring (Clupea harengus) were collected over the course of ∼1 h just north of Georges Bank in the Northwest Atlantic. Although the fish may not have been in their natural, undisturbed state, we observed what appeared to be the fish school fragmenting and dispersing, using a split-beam and a multibeam echosounder. Calibrated, 38 kHz, split-beam echosounder (Simrad EK60) and trawl-catch data provided accurate measures of the fish density beneath the vessel. Uncalibrated, 400 kHz, multibeam-echosounder (Reson 7125) data provided synoptic observations of the fish school including estimates of the school volume, morphology, and behaviour. Observations of the angular dependence in the multibeam-echosounder measurements of backscatter from fish allow investigation of the efficacy of extrapolating fish-school densities measured by the split-beam echosounder to the entire school.
Department
Center for Coastal and Ocean Mapping
Publication Date
4-9-2009
Volume
66, Issue 6
Journal Title
ICES Journal of Marine Science
Pages
1270-1277
Publisher Place
New York, NY, USA
Publisher
Elsevier
Digital Object Identifier (DOI)
10.1093/icesjms/fsp090
Document Type
Journal Article
Recommended Citation
Weber, T. C., Peña, H., and Jech, J. M. 2009. Consecutive acoustic observations of an Atlantic herring school in the Northwest Atlantic. – ICES Journal of Marine Science, 66: 1270–1277.