Skip Navigation


ICES Journal of Marine Science: Journal du Conseil Advance Access originally published online on March 18, 2009
ICES Journal of Marine Science: Journal du Conseil 2009 66(6):1245-1251; doi:10.1093/icesjms/fsp040
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
66/6/1245    most recent
fsp040v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Cutter, G. R.
Right arrow Articles by Demer, D. A.
PubMed
Right arrow Articles by Cutter, G. R.
Right arrow Articles by Demer, D. A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© United States Government, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center 2009

This article appears in the following ICES Journal of Marine Science issue: The Ecosystem Approach with Fisheries Acoustics and Complementary Technologies [View the issue table of contents]

Modelling three-dimensional directivity of sound scattering by Antarctic krill: progress towards biomass estimation using multibeam sonar

George R. Cutter1, Josiah S. Renfree1, Martin J. Cox2, Andrew S. Brierley2 and David A. Demer1

1 Southwest Fisheries Science Center, 8604 La Jolla Shores Drive, La Jolla, CA 92037, USA
2 Gatty Marine Laboratory, School of Biology, University of St Andrews, Fife KY16 8LB, Scotland, UK

Correspondence to G. R. Cutter: tel: +1 858 546 5691; fax: +1 858 546 5656; e-mail: george.cutter{at}noaa.gov

Cutter, G. R., Renfree, J. S., Cox, M. J., Brierley, A. S., and Demer, D. A. 2009. Modelling three-dimensional directivity of sound scattering by Antarctic krill: progress towards biomass estimation using multibeam sonar. – ICES Journal of Marine Science, 66: 1245–1251.

Target strength (TS) estimation is a principal source of uncertainty in acoustic surveys of Antarctic krill (Euphausia superba). Although TS is strongly dependent on krill orientation, there is a paucity of information in this regard. This paper considers the potential for narrow-bandwidth, multibeam-echosounder (MBE) data to be used for estimating the orientations of krill beneath survey vessels. First, software was developed to predict MBE measurements of the directivity patterns of acoustic scattering from individual or aggregated krill in any orientation. Based on the distorted-wave, Born approximation model (DWBA), scattering intensities are predicted vs. MBE angles for specified distributions of krill orientations (pitch, roll, and yaw angles) and swarm densities. Results indicate that certain distributions of orientations, perhaps indicative of particular behaviour, should be apparent from the sonar data. The model results are compared with measurements on krill made using a 200-kHz MBE deployed from a small craft off Cape Shirreff, Livingston Island, Antarctica, in summer 2006. The stochastic DWBA model is then invoked to explain disparities between the model predictions and MBE measurements.

Keywords: Antarctic krill, directivity, incidence angle, multibeam sonar, orientation, target strength

Received 11 August 2008; accepted 28 December 2008; advance access publication 18 March 2009.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.