Target strength of krill in situ at the frequency of 200kHz
The acoustic survey for krill (Euphausia superba) was carried out in the Indian Sector of the Southern Ocean by the R. V. KAIYO MARU participating in SIBEX I 1983-84. In order to estimate the biomass from the mean volume back-scattering strength (S^^^-_v) measured by the 200kHz echo sounder Furuno F...
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Hokko Maru, Hokkaido Regional Fisheries Research Laboratory/Shimonoseki University of Fisheries/Far Seas Fisheries Research Laboratory
1986
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ftnipr:oai:nipr.repo.nii.ac.jp:00001884 2023-05-15T16:08:28+02:00 Target strength of krill in situ at the frequency of 200kHz Kakusuke Nakayama Kunio Shirakihara Yuzo Komaki 1986-02 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1884 http://id.nii.ac.jp/1291/00001884/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1884&item_no=1&attribute_id=18&file_no=1 en eng Hokko Maru, Hokkaido Regional Fisheries Research Laboratory/Shimonoseki University of Fisheries/Far Seas Fisheries Research Laboratory https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1884 http://id.nii.ac.jp/1291/00001884/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 40, 153-161(1986-02) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1884&item_no=1&attribute_id=18&file_no=1 Departmental Bulletin Paper P(論文) 1986 ftnipr 2022-11-12T19:42:40Z The acoustic survey for krill (Euphausia superba) was carried out in the Indian Sector of the Southern Ocean by the R. V. KAIYO MARU participating in SIBEX I 1983-84. In order to estimate the biomass from the mean volume back-scattering strength (S^^^-_v) measured by the 200kHz echo sounder Furuno FQ-50,the mean target strength ( ^^^-) of krill in situ at the same frequency was estimated in the area surveyed. The ^^^- was obtained from both density and S^^^-_v for the krill aggregation in the natural conditions. The density was estimated by means of the echo sounder Furuno FE-101 which possesses a resolution at 455kHz high enough to detect the individual krills; the volume of water insonified by the beam was estimated from the recorded duration of the echo traces, and the number of krill in the volume was obtained by counting the echo traces. Two experiments to estimate the ^^^- were made about 1 hour before sunset, on board the vessel driftingoover the aggregation spreading near the surface. The mean densities estimated from the experiments were 50.0 nd 61.6 individ./m^3. The corresponding S^^^-_v were -51.0 and -50.4dB, respectively. The mean wet weight of the krill samples from the aggregation was 0.62g. An estimate of the ^^^- of 0.62g krill was -68.1dB. The ^^^- per kg was calculated as -36.0dB. Report Euphausia superba Memoirs of National Institute of Polar Research Polar Research Southern Ocean National Institute of Polar Research Repository, Japan Indian Southern Ocean |
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Open Polar |
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National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
description |
The acoustic survey for krill (Euphausia superba) was carried out in the Indian Sector of the Southern Ocean by the R. V. KAIYO MARU participating in SIBEX I 1983-84. In order to estimate the biomass from the mean volume back-scattering strength (S^^^-_v) measured by the 200kHz echo sounder Furuno FQ-50,the mean target strength ( ^^^-) of krill in situ at the same frequency was estimated in the area surveyed. The ^^^- was obtained from both density and S^^^-_v for the krill aggregation in the natural conditions. The density was estimated by means of the echo sounder Furuno FE-101 which possesses a resolution at 455kHz high enough to detect the individual krills; the volume of water insonified by the beam was estimated from the recorded duration of the echo traces, and the number of krill in the volume was obtained by counting the echo traces. Two experiments to estimate the ^^^- were made about 1 hour before sunset, on board the vessel driftingoover the aggregation spreading near the surface. The mean densities estimated from the experiments were 50.0 nd 61.6 individ./m^3. The corresponding S^^^-_v were -51.0 and -50.4dB, respectively. The mean wet weight of the krill samples from the aggregation was 0.62g. An estimate of the ^^^- of 0.62g krill was -68.1dB. The ^^^- per kg was calculated as -36.0dB. |
format |
Report |
author |
Kakusuke Nakayama Kunio Shirakihara Yuzo Komaki |
spellingShingle |
Kakusuke Nakayama Kunio Shirakihara Yuzo Komaki Target strength of krill in situ at the frequency of 200kHz |
author_facet |
Kakusuke Nakayama Kunio Shirakihara Yuzo Komaki |
author_sort |
Kakusuke Nakayama |
title |
Target strength of krill in situ at the frequency of 200kHz |
title_short |
Target strength of krill in situ at the frequency of 200kHz |
title_full |
Target strength of krill in situ at the frequency of 200kHz |
title_fullStr |
Target strength of krill in situ at the frequency of 200kHz |
title_full_unstemmed |
Target strength of krill in situ at the frequency of 200kHz |
title_sort |
target strength of krill in situ at the frequency of 200khz |
publisher |
Hokko Maru, Hokkaido Regional Fisheries Research Laboratory/Shimonoseki University of Fisheries/Far Seas Fisheries Research Laboratory |
publishDate |
1986 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1884 http://id.nii.ac.jp/1291/00001884/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1884&item_no=1&attribute_id=18&file_no=1 |
geographic |
Indian Southern Ocean |
geographic_facet |
Indian Southern Ocean |
genre |
Euphausia superba Memoirs of National Institute of Polar Research Polar Research Southern Ocean |
genre_facet |
Euphausia superba Memoirs of National Institute of Polar Research Polar Research Southern Ocean |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1884 http://id.nii.ac.jp/1291/00001884/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 40, 153-161(1986-02) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1884&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766404522582736896 |