Stress factors resulting from the Arctic vernal sea-ice melt
International audience During sea-ice melt in the Arctic, primary production by sympagic (sea-ice) algae can be exported efficiently to the seabed if sinking rates are rapid and activities of associated heterotrophic bacteria are limited. Salinity stress due to melting ice has been suggested to acco...
Published in: | Elementa: Science of the Anthropocene |
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Online Access: | https://hal.archives-ouvertes.fr/hal-03458308 https://doi.org/10.1525/elementa.076 |
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ftccsdartic:oai:HAL:hal-03458308v1 2023-05-15T14:56:36+02:00 Stress factors resulting from the Arctic vernal sea-ice melt Amiraux, Rémi Burot, Christopher Bonin, Patricia Massé, Guillaume Guasco, Sophie Babin, Marcel Vaultier, Frédéric Rontani, Jean-François Takuvik International Research Laboratory Université Laval Québec (ULaval)-Centre National de la Recherche Scientifique (CNRS) 2020-11-20 https://hal.archives-ouvertes.fr/hal-03458308 https://doi.org/10.1525/elementa.076 en eng HAL CCSD University of California Press info:eu-repo/semantics/altIdentifier/doi/10.1525/elementa.076 hal-03458308 https://hal.archives-ouvertes.fr/hal-03458308 doi:10.1525/elementa.076 EISSN: 2325-1026 Elementa: Science of the Anthropocene https://hal.archives-ouvertes.fr/hal-03458308 Elementa: Science of the Anthropocene, University of California Press, 2020, 8 (1), ⟨10.1525/elementa.076⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2020 ftccsdartic https://doi.org/10.1525/elementa.076 2021-12-04T23:25:34Z International audience During sea-ice melt in the Arctic, primary production by sympagic (sea-ice) algae can be exported efficiently to the seabed if sinking rates are rapid and activities of associated heterotrophic bacteria are limited. Salinity stress due to melting ice has been suggested to account for such low bacterial activity. We further tested this hypothesis by analyzing samples of sea ice and sinking particles collected from May 18 to June 29, 2016, in western Baffin Bay as part of the Green Edge project. We applied a method not previously used in polar regions—quantitative PCR coupled to the propidium monoazide DNA-binding method—to evaluate the viability of bacteria associated with sympagic and sinking algae. We also measured cis-trans isomerase activity, known to indicate rapid bacterial response to salinity stress in culture studies, as well as free fatty acids known to be produced by algae as bactericidal compounds. The viability of sympagic-associated bacteria was strong in May (only approximately 10% mortality of total bacteria) and weaker in June (average mortality of 43%; maximum of 75%), with instances of elevated mortality in sinking particle samples across the time series (up to 72%). Short-term stress reflected by cis-trans isomerase activity was observed only in samples of sinking particles collected early in the time series. Following snow melt, however, and saturating levels of photosynthetically active radiation in June, we observed enhanced ice-algal production of bactericidal compounds (free palmitoleic acid; up to 4.8 mg L–1). We thus suggest that protection of sinking sympagic material from bacterial degradation early in a melt season results from low bacterial activity due to salinity stress, while later in the season, algal production of bactericidal compounds induces bacterial mortality. A succession of bacterial stressors during Arctic ice melt helps to explain the efficient export of sea-ice algal material to the seabed. Article in Journal/Newspaper Arctic Baffin Bay Baffin Bay Baffin ice algae Sea ice Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Arctic Baffin Bay Elementa: Science of the Anthropocene 8 1 |
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Open Polar |
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Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
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ftccsdartic |
language |
English |
topic |
[SDE]Environmental Sciences |
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[SDE]Environmental Sciences Amiraux, Rémi Burot, Christopher Bonin, Patricia Massé, Guillaume Guasco, Sophie Babin, Marcel Vaultier, Frédéric Rontani, Jean-François Stress factors resulting from the Arctic vernal sea-ice melt |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience During sea-ice melt in the Arctic, primary production by sympagic (sea-ice) algae can be exported efficiently to the seabed if sinking rates are rapid and activities of associated heterotrophic bacteria are limited. Salinity stress due to melting ice has been suggested to account for such low bacterial activity. We further tested this hypothesis by analyzing samples of sea ice and sinking particles collected from May 18 to June 29, 2016, in western Baffin Bay as part of the Green Edge project. We applied a method not previously used in polar regions—quantitative PCR coupled to the propidium monoazide DNA-binding method—to evaluate the viability of bacteria associated with sympagic and sinking algae. We also measured cis-trans isomerase activity, known to indicate rapid bacterial response to salinity stress in culture studies, as well as free fatty acids known to be produced by algae as bactericidal compounds. The viability of sympagic-associated bacteria was strong in May (only approximately 10% mortality of total bacteria) and weaker in June (average mortality of 43%; maximum of 75%), with instances of elevated mortality in sinking particle samples across the time series (up to 72%). Short-term stress reflected by cis-trans isomerase activity was observed only in samples of sinking particles collected early in the time series. Following snow melt, however, and saturating levels of photosynthetically active radiation in June, we observed enhanced ice-algal production of bactericidal compounds (free palmitoleic acid; up to 4.8 mg L–1). We thus suggest that protection of sinking sympagic material from bacterial degradation early in a melt season results from low bacterial activity due to salinity stress, while later in the season, algal production of bactericidal compounds induces bacterial mortality. A succession of bacterial stressors during Arctic ice melt helps to explain the efficient export of sea-ice algal material to the seabed. |
author2 |
Takuvik International Research Laboratory Université Laval Québec (ULaval)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Amiraux, Rémi Burot, Christopher Bonin, Patricia Massé, Guillaume Guasco, Sophie Babin, Marcel Vaultier, Frédéric Rontani, Jean-François |
author_facet |
Amiraux, Rémi Burot, Christopher Bonin, Patricia Massé, Guillaume Guasco, Sophie Babin, Marcel Vaultier, Frédéric Rontani, Jean-François |
author_sort |
Amiraux, Rémi |
title |
Stress factors resulting from the Arctic vernal sea-ice melt |
title_short |
Stress factors resulting from the Arctic vernal sea-ice melt |
title_full |
Stress factors resulting from the Arctic vernal sea-ice melt |
title_fullStr |
Stress factors resulting from the Arctic vernal sea-ice melt |
title_full_unstemmed |
Stress factors resulting from the Arctic vernal sea-ice melt |
title_sort |
stress factors resulting from the arctic vernal sea-ice melt |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal.archives-ouvertes.fr/hal-03458308 https://doi.org/10.1525/elementa.076 |
geographic |
Arctic Baffin Bay |
geographic_facet |
Arctic Baffin Bay |
genre |
Arctic Baffin Bay Baffin Bay Baffin ice algae Sea ice |
genre_facet |
Arctic Baffin Bay Baffin Bay Baffin ice algae Sea ice |
op_source |
EISSN: 2325-1026 Elementa: Science of the Anthropocene https://hal.archives-ouvertes.fr/hal-03458308 Elementa: Science of the Anthropocene, University of California Press, 2020, 8 (1), ⟨10.1525/elementa.076⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1525/elementa.076 hal-03458308 https://hal.archives-ouvertes.fr/hal-03458308 doi:10.1525/elementa.076 |
op_doi |
https://doi.org/10.1525/elementa.076 |
container_title |
Elementa: Science of the Anthropocene |
container_volume |
8 |
container_issue |
1 |
_version_ |
1766328694722265088 |