Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun
International audience Despite the midnight sun, herbivore copepods Calanus hyperboreus, C. glacialis and Pseudocalanus acuspes displayed a normal diel vertical migration (NDVM) under the ice cover of Barrow Strait in spring, ascending into the chlorophyll-rich under-ice surface layer around maximum...
Published in: | Journal of Plankton Research |
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Online Access: | https://hal.archives-ouvertes.fr/hal-03483043 https://doi.org/10.1093/plankt/23.11.1263 |
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ftunivnantes:oai:HAL:hal-03483043v1 2023-05-15T14:30:29+02:00 Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun Fortier, M Fortier, L Hattori, H Saito, H Legendre, L Université Laval Québec (ULaval) Laboratoire d'océanographie de Villefranche (LOV) Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV) Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) 2001 https://hal.archives-ouvertes.fr/hal-03483043 https://doi.org/10.1093/plankt/23.11.1263 en eng HAL CCSD Oxford University Press (OUP) info:eu-repo/semantics/altIdentifier/doi/10.1093/plankt/23.11.1263 hal-03483043 https://hal.archives-ouvertes.fr/hal-03483043 doi:10.1093/plankt/23.11.1263 ISSN: 0142-7873 EISSN: 1464-3774 Journal of Plankton Research https://hal.archives-ouvertes.fr/hal-03483043 Journal of Plankton Research, Oxford University Press (OUP), 2001, 23 (11), pp.1263-1278. ⟨10.1093/plankt/23.11.1263⟩ [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2001 ftunivnantes https://doi.org/10.1093/plankt/23.11.1263 2022-08-16T22:47:23Z International audience Despite the midnight sun, herbivore copepods Calanus hyperboreus, C. glacialis and Pseudocalanus acuspes displayed a normal diel vertical migration (NDVM) under the ice cover of Barrow Strait in spring, ascending into the chlorophyll-rich under-ice surface layer around maximum relative rate of change in irradiance (DeltaI/I) at dusk but returning to depth a few hours later, well in advance of the dawn maximum DeltaI/I. Nauplii prey being abundant above 50 m, the upward night-time incursions of the omnivore Metridia longa seldom reached beyond <25 m. In the absence of UV-B radiation or a temperature gradient, migration out of the euphotic layer was interpreted as a reaction to visual predators (e.g. Arctic cod Boreogadus saida and the hyperiid amphipod Themisto libellula). Swarms of T. libellula actively preying on copepods accumulated at the ice-water interface at dusk. Low vulnerability to visual predators and a more uniform vertical distribution of their food explained the limited DVM of the small omnivores Microcalanus pygmaeus, Oithona similis and Oncaea borealis. Once the feeding migrations developed, the daytime depth of the centre of mass of the distribution of a copepod was correlated to its size (r(2) = 0.63). Our observations suggest that, under Arctic sea ice, interspecific differences in the pattern and extent of copepod DVM can be related to the vertical distribution of potential food and to vulnerability to visual predators. Article in Journal/Newspaper Arctic cod Arctic Boreogadus saida Calanus hyperboreus Sea ice Themisto Themisto libellula Copepods midnight sun Université de Nantes: HAL-UNIV-NANTES Arctic Barrow Strait ENVELOPE(-94.168,-94.168,74.402,74.402) Journal of Plankton Research 23 11 1263 1278 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Fortier, M Fortier, L Hattori, H Saito, H Legendre, L Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun |
topic_facet |
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience Despite the midnight sun, herbivore copepods Calanus hyperboreus, C. glacialis and Pseudocalanus acuspes displayed a normal diel vertical migration (NDVM) under the ice cover of Barrow Strait in spring, ascending into the chlorophyll-rich under-ice surface layer around maximum relative rate of change in irradiance (DeltaI/I) at dusk but returning to depth a few hours later, well in advance of the dawn maximum DeltaI/I. Nauplii prey being abundant above 50 m, the upward night-time incursions of the omnivore Metridia longa seldom reached beyond <25 m. In the absence of UV-B radiation or a temperature gradient, migration out of the euphotic layer was interpreted as a reaction to visual predators (e.g. Arctic cod Boreogadus saida and the hyperiid amphipod Themisto libellula). Swarms of T. libellula actively preying on copepods accumulated at the ice-water interface at dusk. Low vulnerability to visual predators and a more uniform vertical distribution of their food explained the limited DVM of the small omnivores Microcalanus pygmaeus, Oithona similis and Oncaea borealis. Once the feeding migrations developed, the daytime depth of the centre of mass of the distribution of a copepod was correlated to its size (r(2) = 0.63). Our observations suggest that, under Arctic sea ice, interspecific differences in the pattern and extent of copepod DVM can be related to the vertical distribution of potential food and to vulnerability to visual predators. |
author2 |
Université Laval Québec (ULaval) Laboratoire d'océanographie de Villefranche (LOV) Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV) Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Fortier, M Fortier, L Hattori, H Saito, H Legendre, L |
author_facet |
Fortier, M Fortier, L Hattori, H Saito, H Legendre, L |
author_sort |
Fortier, M |
title |
Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun |
title_short |
Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun |
title_full |
Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun |
title_fullStr |
Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun |
title_full_unstemmed |
Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun |
title_sort |
visual predators and the diel vertical migration of copepods under arctic sea ice during the midnight sun |
publisher |
HAL CCSD |
publishDate |
2001 |
url |
https://hal.archives-ouvertes.fr/hal-03483043 https://doi.org/10.1093/plankt/23.11.1263 |
long_lat |
ENVELOPE(-94.168,-94.168,74.402,74.402) |
geographic |
Arctic Barrow Strait |
geographic_facet |
Arctic Barrow Strait |
genre |
Arctic cod Arctic Boreogadus saida Calanus hyperboreus Sea ice Themisto Themisto libellula Copepods midnight sun |
genre_facet |
Arctic cod Arctic Boreogadus saida Calanus hyperboreus Sea ice Themisto Themisto libellula Copepods midnight sun |
op_source |
ISSN: 0142-7873 EISSN: 1464-3774 Journal of Plankton Research https://hal.archives-ouvertes.fr/hal-03483043 Journal of Plankton Research, Oxford University Press (OUP), 2001, 23 (11), pp.1263-1278. ⟨10.1093/plankt/23.11.1263⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1093/plankt/23.11.1263 hal-03483043 https://hal.archives-ouvertes.fr/hal-03483043 doi:10.1093/plankt/23.11.1263 |
op_doi |
https://doi.org/10.1093/plankt/23.11.1263 |
container_title |
Journal of Plankton Research |
container_volume |
23 |
container_issue |
11 |
container_start_page |
1263 |
op_container_end_page |
1278 |
_version_ |
1766304331418566656 |