The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz
Abstract The target strengths (TS) of Antarctic krill (Euphausia superba) were measured at 70 kHz aboard the research and training vessel “Umitaka-maru” of Tokyo University of Marine Science and Technology in February 2003 during a Southern Ocean survey. The systematic variations of TS vs. the incid...
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Oxford University Press (OUP)
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Online Access: | http://dx.doi.org/10.1016/j.icesjms.2005.07.012 http://academic.oup.com/icesjms/article-pdf/63/1/36/29124642/63-1-36.pdf |
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croxfordunivpr:10.1016/j.icesjms.2005.07.012 2024-09-15T17:44:10+00:00 The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz Amakasu, Kazuo Furusawa, Masahiko 2006 http://dx.doi.org/10.1016/j.icesjms.2005.07.012 http://academic.oup.com/icesjms/article-pdf/63/1/36/29124642/63-1-36.pdf en eng Oxford University Press (OUP) ICES Journal of Marine Science volume 63, issue 1, page 36-45 ISSN 1095-9289 1054-3139 journal-article 2006 croxfordunivpr https://doi.org/10.1016/j.icesjms.2005.07.012 2024-07-15T04:24:45Z Abstract The target strengths (TS) of Antarctic krill (Euphausia superba) were measured at 70 kHz aboard the research and training vessel “Umitaka-maru” of Tokyo University of Marine Science and Technology in February 2003 during a Southern Ocean survey. The systematic variations of TS vs. the incident angle of the ensonified wave, henceforth called TS-patterns, were successfully measured for 12 live Antarctic krill. These measurements were compared with the theoretical TS-patterns predicted by the Distorted-Wave Born Approximation-based deformed-cylinder model (DWBA model). While there was good agreement near the main lobe, the measurements were higher than the model predictions in the side-lobe regions; this is consistent with the observations of others. Several possible causes of this discrepancy such as the bending of abdomen and scattering from pleopods were examined, but no single factor was identified as the cause. Rather, it is likely that the discrepancy is a result of a combination of several factors. Article in Journal/Newspaper Antarc* Antarctic Antarctic Krill Euphausia superba Southern Ocean Oxford University Press ICES Journal of Marine Science 63 1 36 45 |
institution |
Open Polar |
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Oxford University Press |
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croxfordunivpr |
language |
English |
description |
Abstract The target strengths (TS) of Antarctic krill (Euphausia superba) were measured at 70 kHz aboard the research and training vessel “Umitaka-maru” of Tokyo University of Marine Science and Technology in February 2003 during a Southern Ocean survey. The systematic variations of TS vs. the incident angle of the ensonified wave, henceforth called TS-patterns, were successfully measured for 12 live Antarctic krill. These measurements were compared with the theoretical TS-patterns predicted by the Distorted-Wave Born Approximation-based deformed-cylinder model (DWBA model). While there was good agreement near the main lobe, the measurements were higher than the model predictions in the side-lobe regions; this is consistent with the observations of others. Several possible causes of this discrepancy such as the bending of abdomen and scattering from pleopods were examined, but no single factor was identified as the cause. Rather, it is likely that the discrepancy is a result of a combination of several factors. |
format |
Article in Journal/Newspaper |
author |
Amakasu, Kazuo Furusawa, Masahiko |
spellingShingle |
Amakasu, Kazuo Furusawa, Masahiko The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz |
author_facet |
Amakasu, Kazuo Furusawa, Masahiko |
author_sort |
Amakasu, Kazuo |
title |
The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz |
title_short |
The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz |
title_full |
The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz |
title_fullStr |
The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz |
title_full_unstemmed |
The target strength of Antarctic krill (Euphausia superba) measured by the split-beam method in a small tank at 70 kHz |
title_sort |
target strength of antarctic krill (euphausia superba) measured by the split-beam method in a small tank at 70 khz |
publisher |
Oxford University Press (OUP) |
publishDate |
2006 |
url |
http://dx.doi.org/10.1016/j.icesjms.2005.07.012 http://academic.oup.com/icesjms/article-pdf/63/1/36/29124642/63-1-36.pdf |
genre |
Antarc* Antarctic Antarctic Krill Euphausia superba Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Krill Euphausia superba Southern Ocean |
op_source |
ICES Journal of Marine Science volume 63, issue 1, page 36-45 ISSN 1095-9289 1054-3139 |
op_doi |
https://doi.org/10.1016/j.icesjms.2005.07.012 |
container_title |
ICES Journal of Marine Science |
container_volume |
63 |
container_issue |
1 |
container_start_page |
36 |
op_container_end_page |
45 |
_version_ |
1810491558774964224 |