AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun†
Abstract An autonomous underwater vehicle (AUV) carrying 614 kHz RDI acoustic doppler current profilers (ADCPs) was deployed at four locations over the West Spitsbergen outer shelf in July 2010. The backscatter signal recorded by the ADCPs was extracted and analysed to investigate the vertical distr...
Published in: | ICES Journal of Marine Science |
---|---|
Main Authors: | , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Oxford University Press (OUP)
2016
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1093/icesjms/fsw158 http://academic.oup.com/icesjms/article-pdf/74/9/2342/31244616/fsw158.pdf |
id |
croxfordunivpr:10.1093/icesjms/fsw158 |
---|---|
record_format |
openpolar |
spelling |
croxfordunivpr:10.1093/icesjms/fsw158 2024-04-07T07:50:12+00:00 AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† Geoffroy, Maxime Cottier, Finlo R Berge, Jørgen Inall, Mark E Demer, David 2016 http://dx.doi.org/10.1093/icesjms/fsw158 http://academic.oup.com/icesjms/article-pdf/74/9/2342/31244616/fsw158.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model ICES Journal of Marine Science volume 74, issue 9, page 2342-2353 ISSN 1054-3139 1095-9289 Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2016 croxfordunivpr https://doi.org/10.1093/icesjms/fsw158 2024-03-08T03:01:19Z Abstract An autonomous underwater vehicle (AUV) carrying 614 kHz RDI acoustic doppler current profilers (ADCPs) was deployed at four locations over the West Spitsbergen outer shelf in July 2010. The backscatter signal recorded by the ADCPs was extracted and analysed to investigate the vertical distribution and patchiness of pelagic organisms during midnight sun. At the northernmost locations (Norskebanken and Woodfjorden), fresher and colder water prevailed in the surface layer (0–20 m) and scatterers (interpreted as zooplankton and micronekton) were mainly distributed below the pycnocline. In contrast, more saline and warmer Atlantic Water dominated the surface layer at Kongsfjordbanken and Isfjordbanken and scatterers were concentrated in the top 20 m, above the pycnocline. Pelagic scatterers formed patchy aggregations at all locations, but patchiness generally increased with the density of organisms and decreased at depths >80 m. This study contributes to our understanding of the vertical distribution of pelagic organisms in the Arctic, and the spatial coverage of the AUV has extended early acoustic studies limited to Arctic fjords from 1D observations to a broader offshore coverage. Neither synchronized nor unsynchronized vertical migrations were detected, but autonomous vehicles with limited autonomy (<1 day) may not be as effective as long-term mooring deployments or long-range AUVs to study vertical migrations. Short-term AUV-based acoustic surveys of the pelagic communities are nonetheless highly complementary to Eulerian studies, in particular by providing spatial measurements of patchiness. Compared with ship-based or moored acoustic instruments, the 3D trajectory of AUVs also allows using acoustic instruments with higher frequencies and better size resolution, as well as the detection of organisms closer to the surface. Article in Journal/Newspaper Arctic Isfjord* Kongsfjord* Woodfjord* Woodfjorden Zooplankton midnight sun Spitsbergen Oxford University Press Arctic Woodfjorden ENVELOPE(14.000,14.000,79.833,79.833) Norskebanken ENVELOPE(13.500,13.500,80.167,80.167) Isfjordbanken ENVELOPE(11.000,11.000,77.833,77.833) ICES Journal of Marine Science 74 9 2342 2353 |
institution |
Open Polar |
collection |
Oxford University Press |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
spellingShingle |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography Geoffroy, Maxime Cottier, Finlo R Berge, Jørgen Inall, Mark E AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
topic_facet |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract An autonomous underwater vehicle (AUV) carrying 614 kHz RDI acoustic doppler current profilers (ADCPs) was deployed at four locations over the West Spitsbergen outer shelf in July 2010. The backscatter signal recorded by the ADCPs was extracted and analysed to investigate the vertical distribution and patchiness of pelagic organisms during midnight sun. At the northernmost locations (Norskebanken and Woodfjorden), fresher and colder water prevailed in the surface layer (0–20 m) and scatterers (interpreted as zooplankton and micronekton) were mainly distributed below the pycnocline. In contrast, more saline and warmer Atlantic Water dominated the surface layer at Kongsfjordbanken and Isfjordbanken and scatterers were concentrated in the top 20 m, above the pycnocline. Pelagic scatterers formed patchy aggregations at all locations, but patchiness generally increased with the density of organisms and decreased at depths >80 m. This study contributes to our understanding of the vertical distribution of pelagic organisms in the Arctic, and the spatial coverage of the AUV has extended early acoustic studies limited to Arctic fjords from 1D observations to a broader offshore coverage. Neither synchronized nor unsynchronized vertical migrations were detected, but autonomous vehicles with limited autonomy (<1 day) may not be as effective as long-term mooring deployments or long-range AUVs to study vertical migrations. Short-term AUV-based acoustic surveys of the pelagic communities are nonetheless highly complementary to Eulerian studies, in particular by providing spatial measurements of patchiness. Compared with ship-based or moored acoustic instruments, the 3D trajectory of AUVs also allows using acoustic instruments with higher frequencies and better size resolution, as well as the detection of organisms closer to the surface. |
author2 |
Demer, David |
format |
Article in Journal/Newspaper |
author |
Geoffroy, Maxime Cottier, Finlo R Berge, Jørgen Inall, Mark E |
author_facet |
Geoffroy, Maxime Cottier, Finlo R Berge, Jørgen Inall, Mark E |
author_sort |
Geoffroy, Maxime |
title |
AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
title_short |
AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
title_full |
AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
title_fullStr |
AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
title_full_unstemmed |
AUV-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
title_sort |
auv-based acoustic observations of the distribution and patchiness of pelagic scattering layers during midnight sun† |
publisher |
Oxford University Press (OUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1093/icesjms/fsw158 http://academic.oup.com/icesjms/article-pdf/74/9/2342/31244616/fsw158.pdf |
long_lat |
ENVELOPE(14.000,14.000,79.833,79.833) ENVELOPE(13.500,13.500,80.167,80.167) ENVELOPE(11.000,11.000,77.833,77.833) |
geographic |
Arctic Woodfjorden Norskebanken Isfjordbanken |
geographic_facet |
Arctic Woodfjorden Norskebanken Isfjordbanken |
genre |
Arctic Isfjord* Kongsfjord* Woodfjord* Woodfjorden Zooplankton midnight sun Spitsbergen |
genre_facet |
Arctic Isfjord* Kongsfjord* Woodfjord* Woodfjorden Zooplankton midnight sun Spitsbergen |
op_source |
ICES Journal of Marine Science volume 74, issue 9, page 2342-2353 ISSN 1054-3139 1095-9289 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/icesjms/fsw158 |
container_title |
ICES Journal of Marine Science |
container_volume |
74 |
container_issue |
9 |
container_start_page |
2342 |
op_container_end_page |
2353 |
_version_ |
1795664881898225664 |