Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn
In September 2016, a marine ecosystem survey covered all trophic levels from phytoplankton to seals in the Arctic Ocean to the west and north of Svalbard. At the ice edge, 26 harp seals were sampled to assess whether recent environmental changes had affected their diets and body condition by compari...
Published in: | Progress in Oceanography |
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Online Access: | https://hdl.handle.net/10037/20430 https://doi.org/10.1016/j.pocean.2020.102498 |
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ftunivtroemsoe:oai:munin.uit.no:10037/20430 2023-05-15T14:23:29+02:00 Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn Haug, Tore Biuw, Martin Gjøsæter, Harald Knutsen, Tor Lindstrøm, Ulf MacKanzie, Kirsteen M. Meier, Sonnich Nilssen, Kjell Tormod 2020-12-28 https://hdl.handle.net/10037/20430 https://doi.org/10.1016/j.pocean.2020.102498 eng eng Elsevier Progress in Oceanography info:eu-repo/grantAgreement/RCN/SIPHINIFES/228896/Norway/The Arctic Ocean Ecosystem - Polhavets økosystem// info:eu-repo/grantAgreement/RCN/NANSEN/276730/Norway/NANSEN/The Nansen Legacy/ Haug, Biuw, Gjøsæter, Knutsen, Lindstrøm, MacKanzie, Meier, Nilssen. Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn. Progress in Oceanography. 2020 FRIDAID 1868779 doi:10.1016/j.pocean.2020.102498 0079-6611 1873-4472 https://hdl.handle.net/10037/20430 openAccess Copyright 2020 The Author(s) VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Journal article Tidsskriftartikkel Peer reviewed publishedVersion 2020 ftunivtroemsoe https://doi.org/10.1016/j.pocean.2020.102498 2021-06-25T17:57:58Z In September 2016, a marine ecosystem survey covered all trophic levels from phytoplankton to seals in the Arctic Ocean to the west and north of Svalbard. At the ice edge, 26 harp seals were sampled to assess whether recent environmental changes had affected their diets and body condition by comparing our current results with previous investigations conducted 2–3 decades ago in the northern Barents Sea, when the ice edge was located much further south. Our results suggest that the body condition was slightly but significantly lower for one year and older seals in 2016 compared with seals sampled in the early 1990s. Furthermore, we confirmed previous findings that polar cod (Boreogadus saida) and the pelagic hyperiid amphipod Themisto libellula still dominate the seal diet. One consequence of current ice edge localisation north of Svalbard is that the water depth underneath is now 500 m and deeper, which probably explains the absence of bottom associated species, and the presence of species such as Atlantic cod (Gadus morhua) and blue whiting (Micromesistius poutassou) as alternative species in addition to polar cod and T. libellula in the seal diets. Stable isotope data also suggest possible long-term importance in the seal diet of T. libellula and of low trophic level benthopelagic prey such as the squid Gonatus fabricii over mid-trophic level pelagic fishes, but with a strong component of small, benthopelagic fish such as blue whiting. The long-term importance of pelagic crustaceans was also suggested from the fatty acid analyses. Assessment of the abundance of prey showed that T. libellula was by far the most abundant prey species in the upper water layers, followed by krill (mainly Thysanoessa inermis), Atlantic cod and polar cod. Prey-preference analyses indicated that polar cod was the most preferred prey species for the seals. Article in Journal/Newspaper Arctic Arctic Arctic Ocean atlantic cod Barents Sea Boreogadus saida Gadus morhua Harp Seal Phytoplankton polar cod Svalbard Themisto Themisto libellula Thysanoessa inermis University of Tromsø: Munin Open Research Archive Arctic Arctic Ocean Barents Sea Svalbard Progress in Oceanography 191 102498 |
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 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 |
spellingShingle |
VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Haug, Tore Biuw, Martin Gjøsæter, Harald Knutsen, Tor Lindstrøm, Ulf MacKanzie, Kirsteen M. Meier, Sonnich Nilssen, Kjell Tormod Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn |
topic_facet |
VDP::Mathematics and natural science: 400::Zoology and botany: 480 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 |
description |
In September 2016, a marine ecosystem survey covered all trophic levels from phytoplankton to seals in the Arctic Ocean to the west and north of Svalbard. At the ice edge, 26 harp seals were sampled to assess whether recent environmental changes had affected their diets and body condition by comparing our current results with previous investigations conducted 2–3 decades ago in the northern Barents Sea, when the ice edge was located much further south. Our results suggest that the body condition was slightly but significantly lower for one year and older seals in 2016 compared with seals sampled in the early 1990s. Furthermore, we confirmed previous findings that polar cod (Boreogadus saida) and the pelagic hyperiid amphipod Themisto libellula still dominate the seal diet. One consequence of current ice edge localisation north of Svalbard is that the water depth underneath is now 500 m and deeper, which probably explains the absence of bottom associated species, and the presence of species such as Atlantic cod (Gadus morhua) and blue whiting (Micromesistius poutassou) as alternative species in addition to polar cod and T. libellula in the seal diets. Stable isotope data also suggest possible long-term importance in the seal diet of T. libellula and of low trophic level benthopelagic prey such as the squid Gonatus fabricii over mid-trophic level pelagic fishes, but with a strong component of small, benthopelagic fish such as blue whiting. The long-term importance of pelagic crustaceans was also suggested from the fatty acid analyses. Assessment of the abundance of prey showed that T. libellula was by far the most abundant prey species in the upper water layers, followed by krill (mainly Thysanoessa inermis), Atlantic cod and polar cod. Prey-preference analyses indicated that polar cod was the most preferred prey species for the seals. |
format |
Article in Journal/Newspaper |
author |
Haug, Tore Biuw, Martin Gjøsæter, Harald Knutsen, Tor Lindstrøm, Ulf MacKanzie, Kirsteen M. Meier, Sonnich Nilssen, Kjell Tormod |
author_facet |
Haug, Tore Biuw, Martin Gjøsæter, Harald Knutsen, Tor Lindstrøm, Ulf MacKanzie, Kirsteen M. Meier, Sonnich Nilssen, Kjell Tormod |
author_sort |
Haug, Tore |
title |
Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn |
title_short |
Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn |
title_full |
Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn |
title_fullStr |
Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn |
title_full_unstemmed |
Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn |
title_sort |
harp seal body condition and trophic interactions with prey in norwegian high arctic waters in early autumn |
publisher |
Elsevier |
publishDate |
2020 |
url |
https://hdl.handle.net/10037/20430 https://doi.org/10.1016/j.pocean.2020.102498 |
geographic |
Arctic Arctic Ocean Barents Sea Svalbard |
geographic_facet |
Arctic Arctic Ocean Barents Sea Svalbard |
genre |
Arctic Arctic Arctic Ocean atlantic cod Barents Sea Boreogadus saida Gadus morhua Harp Seal Phytoplankton polar cod Svalbard Themisto Themisto libellula Thysanoessa inermis |
genre_facet |
Arctic Arctic Arctic Ocean atlantic cod Barents Sea Boreogadus saida Gadus morhua Harp Seal Phytoplankton polar cod Svalbard Themisto Themisto libellula Thysanoessa inermis |
op_relation |
Progress in Oceanography info:eu-repo/grantAgreement/RCN/SIPHINIFES/228896/Norway/The Arctic Ocean Ecosystem - Polhavets økosystem// info:eu-repo/grantAgreement/RCN/NANSEN/276730/Norway/NANSEN/The Nansen Legacy/ Haug, Biuw, Gjøsæter, Knutsen, Lindstrøm, MacKanzie, Meier, Nilssen. Harp seal body condition and trophic interactions with prey in Norwegian high Arctic waters in early autumn. Progress in Oceanography. 2020 FRIDAID 1868779 doi:10.1016/j.pocean.2020.102498 0079-6611 1873-4472 https://hdl.handle.net/10037/20430 |
op_rights |
openAccess Copyright 2020 The Author(s) |
op_doi |
https://doi.org/10.1016/j.pocean.2020.102498 |
container_title |
Progress in Oceanography |
container_volume |
191 |
container_start_page |
102498 |
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1766296030798675968 |