Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships
Mesopelagic sound scattering layers (SSL) are ubiquitous in all oceans. Pelagic organisms within the SSL play important roles as prey for higher trophic levels and in climate regulation through the biological carbon pump. Yet, the biomass and species composition of SSL in the Arctic Ocean remain poo...
Published in: | Frontiers in Marine Science |
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Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Frontiers Media
2019
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Subjects: | |
Online Access: | https://hdl.handle.net/10037/16859 https://doi.org/10.3389/fmars.2019.00364 |
id |
ftunivtroemsoe:oai:munin.uit.no:10037/16859 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497 |
spellingShingle |
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497 Geoffroy, Maxime Daase, Malin Cusa, Marine Lure Joana Darnis, Gérald Graeve, Martin Santana Hernadez, Nestor Berge, Jørgen Renaud, Paul Eric Cottier, Finlo Robert Falk-Petersen, Stig Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships |
topic_facet |
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497 |
description |
Mesopelagic sound scattering layers (SSL) are ubiquitous in all oceans. Pelagic organisms within the SSL play important roles as prey for higher trophic levels and in climate regulation through the biological carbon pump. Yet, the biomass and species composition of SSL in the Arctic Ocean remain poorly documented, particularly in winter. A multifrequency echosounder detected a SSL north of Svalbard, from 79.8 to 81.4°N, in January 2016, August 2016, and January 2017. Midwater trawl sampling confirmed that the SSL comprised zooplankton and pelagic fish of boreal and Arctic origins. Arctic cod dominated the fish assemblage in August and juvenile beaked redfish in January. The macrozooplankton community mainly comprised the medusa Cyanea capillata , the amphipod Themisto libellula , and the euphausiids Meganyctiphanes norvegica in August and Thysanoessa inermis in January. The SSL was located in the Atlantic Water mass, between 200–700 m in August and between 50–500 m in January. In January, the SSL was shallower and weaker above the deeper basin, where less Atlantic Water penetrated. The energy content available in the form of lipids within the SSL was significantly higher in summer than winter. The biomass within the SSL was >12-fold higher in summer, and the diversity of fish was slightly higher than in winter (12 vs. 9 species). We suggest that these differences are mainly related to life history and ontogenetic changes resulting in a descent toward the seafloor, outside the mesopelagic layer, in winter. In addition, some fish species of boreal origin, such as the spotted barracudina, did not seem to survive the polar night when advected from the Atlantic into the Arctic. Others, mainly juvenile beaked redfish, were abundant in both summer and winter, implying that the species can survive the polar night and possibly extend its range into the high Arctic. Fatty-acid trophic markers revealed that Arctic cod mainly fed on calanoid copepods while juvenile beaked redfish targeted krill ( Thysanoessa spp.). The relatively high biomass of Arctic cod in August and of redfish in January thus suggests a shift within the SSL, from a Calanus -based food web in summer to a krill-based food web during winter. |
format |
Article in Journal/Newspaper |
author |
Geoffroy, Maxime Daase, Malin Cusa, Marine Lure Joana Darnis, Gérald Graeve, Martin Santana Hernadez, Nestor Berge, Jørgen Renaud, Paul Eric Cottier, Finlo Robert Falk-Petersen, Stig |
author_facet |
Geoffroy, Maxime Daase, Malin Cusa, Marine Lure Joana Darnis, Gérald Graeve, Martin Santana Hernadez, Nestor Berge, Jørgen Renaud, Paul Eric Cottier, Finlo Robert Falk-Petersen, Stig |
author_sort |
Geoffroy, Maxime |
title |
Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships |
title_short |
Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships |
title_full |
Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships |
title_fullStr |
Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships |
title_full_unstemmed |
Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships |
title_sort |
mesopelagic sound scattering layers of the high arctic: seasonal variations in biomass, species assemblage, and trophic relationships |
publisher |
Frontiers Media |
publishDate |
2019 |
url |
https://hdl.handle.net/10037/16859 https://doi.org/10.3389/fmars.2019.00364 |
long_lat |
ENVELOPE(157.417,157.417,-79.633,-79.633) |
geographic |
Arctic Arctic Ocean Medusa Svalbard |
geographic_facet |
Arctic Arctic Ocean Medusa Svalbard |
genre |
Arctic Arctic cod Arctic Arctic Ocean Meganyctiphanes norvegica polar night Svalbard Themisto Themisto libellula Zooplankton Copepods Thysanoessa inermis |
genre_facet |
Arctic Arctic cod Arctic Arctic Ocean Meganyctiphanes norvegica polar night Svalbard Themisto Themisto libellula Zooplankton Copepods Thysanoessa inermis |
op_relation |
Frontiers in Marine Science info:eu-repo/grantAgreement/RCN/POLARPROG/244319/Norway/Arctic Ocean ecosystems - Applied technology, Biological interactions and Consequences in an era of abrupt climate change// info:eu-repo/grantAgreement/RCN/POLARPROG/226417/Norway/Mare incognitum - ecological processes during the polar night// Geoffroy M, Daase M, Cusa M, Darnis G, Graeve M, Santana Hernadez N, Berge J, Renaud P, Cottier FR, Falk-Petersen S. Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships. Frontiers in Marine Science. 2019;6 FRIDAID 1722812 doi:10.3389/fmars.2019.00364 2296-7745 https://hdl.handle.net/10037/16859 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.3389/fmars.2019.00364 |
container_title |
Frontiers in Marine Science |
container_volume |
6 |
_version_ |
1766297609978249216 |
spelling |
ftunivtroemsoe:oai:munin.uit.no:10037/16859 2023-05-15T14:25:11+02:00 Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships Geoffroy, Maxime Daase, Malin Cusa, Marine Lure Joana Darnis, Gérald Graeve, Martin Santana Hernadez, Nestor Berge, Jørgen Renaud, Paul Eric Cottier, Finlo Robert Falk-Petersen, Stig 2019-07-12 https://hdl.handle.net/10037/16859 https://doi.org/10.3389/fmars.2019.00364 eng eng Frontiers Media Frontiers in Marine Science info:eu-repo/grantAgreement/RCN/POLARPROG/244319/Norway/Arctic Ocean ecosystems - Applied technology, Biological interactions and Consequences in an era of abrupt climate change// info:eu-repo/grantAgreement/RCN/POLARPROG/226417/Norway/Mare incognitum - ecological processes during the polar night// Geoffroy M, Daase M, Cusa M, Darnis G, Graeve M, Santana Hernadez N, Berge J, Renaud P, Cottier FR, Falk-Petersen S. Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships. Frontiers in Marine Science. 2019;6 FRIDAID 1722812 doi:10.3389/fmars.2019.00364 2296-7745 https://hdl.handle.net/10037/16859 openAccess VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497 Journal article Tidsskriftartikkel Peer reviewed publishedVersion 2019 ftunivtroemsoe https://doi.org/10.3389/fmars.2019.00364 2021-06-25T17:56:57Z Mesopelagic sound scattering layers (SSL) are ubiquitous in all oceans. Pelagic organisms within the SSL play important roles as prey for higher trophic levels and in climate regulation through the biological carbon pump. Yet, the biomass and species composition of SSL in the Arctic Ocean remain poorly documented, particularly in winter. A multifrequency echosounder detected a SSL north of Svalbard, from 79.8 to 81.4°N, in January 2016, August 2016, and January 2017. Midwater trawl sampling confirmed that the SSL comprised zooplankton and pelagic fish of boreal and Arctic origins. Arctic cod dominated the fish assemblage in August and juvenile beaked redfish in January. The macrozooplankton community mainly comprised the medusa Cyanea capillata , the amphipod Themisto libellula , and the euphausiids Meganyctiphanes norvegica in August and Thysanoessa inermis in January. The SSL was located in the Atlantic Water mass, between 200–700 m in August and between 50–500 m in January. In January, the SSL was shallower and weaker above the deeper basin, where less Atlantic Water penetrated. The energy content available in the form of lipids within the SSL was significantly higher in summer than winter. The biomass within the SSL was >12-fold higher in summer, and the diversity of fish was slightly higher than in winter (12 vs. 9 species). We suggest that these differences are mainly related to life history and ontogenetic changes resulting in a descent toward the seafloor, outside the mesopelagic layer, in winter. In addition, some fish species of boreal origin, such as the spotted barracudina, did not seem to survive the polar night when advected from the Atlantic into the Arctic. Others, mainly juvenile beaked redfish, were abundant in both summer and winter, implying that the species can survive the polar night and possibly extend its range into the high Arctic. Fatty-acid trophic markers revealed that Arctic cod mainly fed on calanoid copepods while juvenile beaked redfish targeted krill ( Thysanoessa spp.). The relatively high biomass of Arctic cod in August and of redfish in January thus suggests a shift within the SSL, from a Calanus -based food web in summer to a krill-based food web during winter. Article in Journal/Newspaper Arctic Arctic cod Arctic Arctic Ocean Meganyctiphanes norvegica polar night Svalbard Themisto Themisto libellula Zooplankton Copepods Thysanoessa inermis University of Tromsø: Munin Open Research Archive Arctic Arctic Ocean Medusa ENVELOPE(157.417,157.417,-79.633,-79.633) Svalbard Frontiers in Marine Science 6 |