Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey
Throughout all oceans, aggregations of zooplankton and ichthyoplankton appear as horizontal sound scattering layers (SSLs) when detected with active acoustic techniques. Quantifying the composition and density of these layers is prone to sampling biases. We conducted a net and trawl survey of the ep...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Canadian Science Publishing
2023
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Online Access: | http://dx.doi.org/10.1139/cjfas-2022-0105 https://cdnsciencepub.com/doi/full-xml/10.1139/cjfas-2022-0105 https://cdnsciencepub.com/doi/pdf/10.1139/cjfas-2022-0105 |
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crcansciencepubl:10.1139/cjfas-2022-0105 2024-05-19T07:46:00+00:00 Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey Dunn, Muriel Pedersen, Geir Basedow, Sünnje L. Daase, Malin Falk-Petersen, Stig Bachelot, Loïc Camus, Lionel Geoffroy, Maxime 2023 http://dx.doi.org/10.1139/cjfas-2022-0105 https://cdnsciencepub.com/doi/full-xml/10.1139/cjfas-2022-0105 https://cdnsciencepub.com/doi/pdf/10.1139/cjfas-2022-0105 en eng Canadian Science Publishing https://creativecommons.org/licenses/by/4.0/deed.en_GB Canadian Journal of Fisheries and Aquatic Sciences volume 80, issue 3, page 451-467 ISSN 0706-652X 1205-7533 journal-article 2023 crcansciencepubl https://doi.org/10.1139/cjfas-2022-0105 2024-04-25T06:52:01Z Throughout all oceans, aggregations of zooplankton and ichthyoplankton appear as horizontal sound scattering layers (SSLs) when detected with active acoustic techniques. Quantifying the composition and density of these layers is prone to sampling biases. We conducted a net and trawl survey of the epipelagic fauna in northern Norway (70° N) in June 2018 while an autonomous surface vehicle equipped with a broadband echosounder (283–383 kHz) surveyed the same region. Densities from the autonomous hydroacoustic survey were calculated using forward estimates from the relative density from the net and trawl, and inversion estimates with statistical data-fitting. All four methods (net, trawl, acoustic forward and inverse methods) identified that copepods dominated the epipelagic SSL, while pteropods, amphipods and fish larvae were present in low densities. The density estimates calculated with the inverse method were higher for mobile zooplankton, such as euphausiid larvae, than with the other methods. We concluded that the inverse method applied to broadband autonomous acoustic surveys can improve density estimates of epipelagic organisms by diminishing avoidance biases and increasing the spatio-temporal resolution of ship-based surveys. Article in Journal/Newspaper Northern Norway Copepods Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences |
institution |
Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
Throughout all oceans, aggregations of zooplankton and ichthyoplankton appear as horizontal sound scattering layers (SSLs) when detected with active acoustic techniques. Quantifying the composition and density of these layers is prone to sampling biases. We conducted a net and trawl survey of the epipelagic fauna in northern Norway (70° N) in June 2018 while an autonomous surface vehicle equipped with a broadband echosounder (283–383 kHz) surveyed the same region. Densities from the autonomous hydroacoustic survey were calculated using forward estimates from the relative density from the net and trawl, and inversion estimates with statistical data-fitting. All four methods (net, trawl, acoustic forward and inverse methods) identified that copepods dominated the epipelagic SSL, while pteropods, amphipods and fish larvae were present in low densities. The density estimates calculated with the inverse method were higher for mobile zooplankton, such as euphausiid larvae, than with the other methods. We concluded that the inverse method applied to broadband autonomous acoustic surveys can improve density estimates of epipelagic organisms by diminishing avoidance biases and increasing the spatio-temporal resolution of ship-based surveys. |
format |
Article in Journal/Newspaper |
author |
Dunn, Muriel Pedersen, Geir Basedow, Sünnje L. Daase, Malin Falk-Petersen, Stig Bachelot, Loïc Camus, Lionel Geoffroy, Maxime |
spellingShingle |
Dunn, Muriel Pedersen, Geir Basedow, Sünnje L. Daase, Malin Falk-Petersen, Stig Bachelot, Loïc Camus, Lionel Geoffroy, Maxime Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
author_facet |
Dunn, Muriel Pedersen, Geir Basedow, Sünnje L. Daase, Malin Falk-Petersen, Stig Bachelot, Loïc Camus, Lionel Geoffroy, Maxime |
author_sort |
Dunn, Muriel |
title |
Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
title_short |
Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
title_full |
Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
title_fullStr |
Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
title_full_unstemmed |
Inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
title_sort |
inverse method applied to autonomous broadband hydroacoustic survey detects higher densities of zooplankton in near-surface aggregations than vessel-based net survey |
publisher |
Canadian Science Publishing |
publishDate |
2023 |
url |
http://dx.doi.org/10.1139/cjfas-2022-0105 https://cdnsciencepub.com/doi/full-xml/10.1139/cjfas-2022-0105 https://cdnsciencepub.com/doi/pdf/10.1139/cjfas-2022-0105 |
genre |
Northern Norway Copepods |
genre_facet |
Northern Norway Copepods |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 80, issue 3, page 451-467 ISSN 0706-652X 1205-7533 |
op_rights |
https://creativecommons.org/licenses/by/4.0/deed.en_GB |
op_doi |
https://doi.org/10.1139/cjfas-2022-0105 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
_version_ |
1799486130445352960 |