Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength
Abstract In two surveys in an Icelandic fjord, September 2016 and October 2018, the target strength (TS) of the euphausiid Thysanoessa raschii was estimated at four frequencies (38, 70, 120, 200 kHz) by matching the acoustic backscatter to the number of euphausiids detected by a Video Plankton Recor...
Published in: | Journal of Plankton Research |
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Oxford University Press (OUP)
2022
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Online Access: | http://dx.doi.org/10.1093/plankt/fbac068 https://academic.oup.com/plankt/article-pdf/45/1/37/50499742/fbac068.pdf |
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croxfordunivpr:10.1093/plankt/fbac068 2023-06-18T03:43:20+02:00 Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength Reynisson, Pall Gislason, Astthor Lawson, Gareth L NOAA Fisheries Quantitative Ecology and Socioeconomics Training AVS Foundation Marine Research Institute in Iceland 2022 http://dx.doi.org/10.1093/plankt/fbac068 https://academic.oup.com/plankt/article-pdf/45/1/37/50499742/fbac068.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model Journal of Plankton Research volume 45, issue 1, page 37-51 ISSN 0142-7873 1464-3774 Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2022 croxfordunivpr https://doi.org/10.1093/plankt/fbac068 2023-06-02T09:25:46Z Abstract In two surveys in an Icelandic fjord, September 2016 and October 2018, the target strength (TS) of the euphausiid Thysanoessa raschii was estimated at four frequencies (38, 70, 120, 200 kHz) by matching the acoustic backscatter to the number of euphausiids detected by a Video Plankton Recorder (VPR). Using forward-looking strobe lights on the VPR and doubling the towing speed lowered the estimated target strength by 4.3 dB. In 2016, the TS for euphausiids of mean length 20.7 mm averaged −98.4, −92.3, −86.6 and −82.8 dB at 38, 70, 120 and 200 kHz frequencies, respectively. In 2018, TS for euphausiids of mean length 19.9 mm averaged −98.2 dB at 38 kHz and −88.3 dB at 120 kHz. Theoretical modeling using a Distorted-Wave Born Approximation-based approach was used to compute the average target strength for the observed length distributions and for several density and sound speed contrast (g, h) and orientations. Except at 38 kHz, these results are in reasonable agreement with the TS estimated from the VPR-acoustic comparisons. The methodological approach presented provides an alternative to net-acoustic comparison or modeling for the estimation of euphausiid target strength. Article in Journal/Newspaper Thysanoessa raschii Oxford University Press (via Crossref) Journal of Plankton Research |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Reynisson, Pall Gislason, Astthor Lawson, Gareth L Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength |
topic_facet |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Abstract In two surveys in an Icelandic fjord, September 2016 and October 2018, the target strength (TS) of the euphausiid Thysanoessa raschii was estimated at four frequencies (38, 70, 120, 200 kHz) by matching the acoustic backscatter to the number of euphausiids detected by a Video Plankton Recorder (VPR). Using forward-looking strobe lights on the VPR and doubling the towing speed lowered the estimated target strength by 4.3 dB. In 2016, the TS for euphausiids of mean length 20.7 mm averaged −98.4, −92.3, −86.6 and −82.8 dB at 38, 70, 120 and 200 kHz frequencies, respectively. In 2018, TS for euphausiids of mean length 19.9 mm averaged −98.2 dB at 38 kHz and −88.3 dB at 120 kHz. Theoretical modeling using a Distorted-Wave Born Approximation-based approach was used to compute the average target strength for the observed length distributions and for several density and sound speed contrast (g, h) and orientations. Except at 38 kHz, these results are in reasonable agreement with the TS estimated from the VPR-acoustic comparisons. The methodological approach presented provides an alternative to net-acoustic comparison or modeling for the estimation of euphausiid target strength. |
author2 |
NOAA Fisheries Quantitative Ecology and Socioeconomics Training AVS Foundation Marine Research Institute in Iceland |
format |
Article in Journal/Newspaper |
author |
Reynisson, Pall Gislason, Astthor Lawson, Gareth L |
author_facet |
Reynisson, Pall Gislason, Astthor Lawson, Gareth L |
author_sort |
Reynisson, Pall |
title |
Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength |
title_short |
Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength |
title_full |
Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength |
title_fullStr |
Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength |
title_full_unstemmed |
Concurrent observations of the euphausiid Thysanoessa raschii in an Icelandic fjord by acoustics and Video Plankton Recorder: comparisons with theoretical models of target strength |
title_sort |
concurrent observations of the euphausiid thysanoessa raschii in an icelandic fjord by acoustics and video plankton recorder: comparisons with theoretical models of target strength |
publisher |
Oxford University Press (OUP) |
publishDate |
2022 |
url |
http://dx.doi.org/10.1093/plankt/fbac068 https://academic.oup.com/plankt/article-pdf/45/1/37/50499742/fbac068.pdf |
genre |
Thysanoessa raschii |
genre_facet |
Thysanoessa raschii |
op_source |
Journal of Plankton Research volume 45, issue 1, page 37-51 ISSN 0142-7873 1464-3774 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/plankt/fbac068 |
container_title |
Journal of Plankton Research |
_version_ |
1769009683681509376 |