Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay
Benthic foraminifera are widely used in oceanography as paleoclimate and paleoenvironmental bio-indicators due to their presence in all marine environments, their sensitivity to environmental changes and their great capacity to fossilize. However, the use of benthic foraminifera as paleoenvironmenta...
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Other Authors: | , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
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HAL CCSD
2019
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Online Access: | https://theses.hal.science/tel-02303043 https://theses.hal.science/tel-02303043/document https://theses.hal.science/tel-02303043/file/RACINE_CALYPSO_2019.pdf |
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ftecolephe:oai:HAL:tel-02303043v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
EPHE (Ecole pratique des hautes études, Paris): HAL |
op_collection_id |
ftecolephe |
language |
French |
topic |
Benthic foraminifera Arctic Primary production Organic matter Foraminifères benthiques Arctique Production primaire Matière organique [SDE.MCG]Environmental Sciences/Global Changes [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Benthic foraminifera Arctic Primary production Organic matter Foraminifères benthiques Arctique Production primaire Matière organique [SDE.MCG]Environmental Sciences/Global Changes [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Racine, Calypso Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay |
topic_facet |
Benthic foraminifera Arctic Primary production Organic matter Foraminifères benthiques Arctique Production primaire Matière organique [SDE.MCG]Environmental Sciences/Global Changes [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
Benthic foraminifera are widely used in oceanography as paleoclimate and paleoenvironmental bio-indicators due to their presence in all marine environments, their sensitivity to environmental changes and their great capacity to fossilize. However, the use of benthic foraminifera as paleoenvironmental proxies requires a good knowledge of the ecological conditions and the parameters controlling species distribution. Although knowledges about the ecology of benthic foraminifera are improving, they remain sporadic in Arctic area, a complex ecosystem characterized by multiple interactions between the atmosphere, the ocean and the cryosphere and particularly sensitive to change and vulnerable to global warming. Temperatures in the Arctic have risen twice as fast as the global average over the past decades, a phenomenon that has been dubbed the “polar amplification of global warming”. In this context, this thesis aims at better understanding the ecology of living benthic foraminifera in Arctic regions and at defining the importance of environmental controls on fauna such as water mass properties, primary productivity, organic matter flux as well as sea-ice dynamics. Living benthic foraminifera were identified in the first centimetres of 21 surface sediment cores collected in three Arctic areas during summer in 2014 and 2015: Baffin Bay and the Barents and Chukchi Seas. These three regions present specific characteristics in terms of sea-ice cover, water mass circulation or primary productivity. Our results suggest that these factors influence the distribution of benthic foraminifera. The flux of organic matter resulting from primary productivity intensified during spring and summer periods near hydrographic polar fronts, sea-ice edges (marginal ice zones) and in the north water polynya (Baffin Bay) increases the fauna’s densities and diversity and favours the development of specific species. Nonionellina labradorica in cold Arctic waters and Cassidulina neoteretis associated with Atlantic waters respond to fresh supply ... |
author2 |
Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Université de Bordeaux Jacques Giraudeau Jérôme Bonnin |
format |
Doctoral or Postdoctoral Thesis |
author |
Racine, Calypso |
author_facet |
Racine, Calypso |
author_sort |
Racine, Calypso |
title |
Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay |
title_short |
Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay |
title_full |
Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay |
title_fullStr |
Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay |
title_full_unstemmed |
Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay |
title_sort |
ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the chukchi sea, barents sea and baffin bay |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://theses.hal.science/tel-02303043 https://theses.hal.science/tel-02303043/document https://theses.hal.science/tel-02303043/file/RACINE_CALYPSO_2019.pdf |
genre |
Arctic Arctique* Baffin Bay Baffin Bay Baffin Barents Sea Chukchi Chukchi Sea Climate change Foraminifera* Global warming Sea ice |
genre_facet |
Arctic Arctique* Baffin Bay Baffin Bay Baffin Barents Sea Chukchi Chukchi Sea Climate change Foraminifera* Global warming Sea ice |
op_source |
https://theses.hal.science/tel-02303043 Milieux et Changements globaux. Université de Bordeaux, 2019. Français. ⟨NNT : 2019BORD0008⟩ |
op_relation |
NNT: 2019BORD0008 tel-02303043 https://theses.hal.science/tel-02303043 https://theses.hal.science/tel-02303043/document https://theses.hal.science/tel-02303043/file/RACINE_CALYPSO_2019.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1799472963990323200 |
spelling |
ftecolephe:oai:HAL:tel-02303043v1 2024-05-19T07:34:47+00:00 Ecology of modern arctic benthic foraminifera within a context of climate change : case studies in the Chukchi Sea, Barents Sea and Baffin Bay Écologie des foraminifères benthiques en domaine arctique dans un contexte de changements climatiques : cas des mers de Chukchi, Barents et Baffin Racine, Calypso Environnements et Paléoenvironnements OCéaniques (EPOC) Observatoire aquitain des sciences de l'univers (OASU) Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) Université de Bordeaux Jacques Giraudeau Jérôme Bonnin 2019-01-28 https://theses.hal.science/tel-02303043 https://theses.hal.science/tel-02303043/document https://theses.hal.science/tel-02303043/file/RACINE_CALYPSO_2019.pdf fr fre HAL CCSD NNT: 2019BORD0008 tel-02303043 https://theses.hal.science/tel-02303043 https://theses.hal.science/tel-02303043/document https://theses.hal.science/tel-02303043/file/RACINE_CALYPSO_2019.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-02303043 Milieux et Changements globaux. Université de Bordeaux, 2019. Français. ⟨NNT : 2019BORD0008⟩ Benthic foraminifera Arctic Primary production Organic matter Foraminifères benthiques Arctique Production primaire Matière organique [SDE.MCG]Environmental Sciences/Global Changes [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/doctoralThesis Theses 2019 ftecolephe 2024-04-25T01:46:21Z Benthic foraminifera are widely used in oceanography as paleoclimate and paleoenvironmental bio-indicators due to their presence in all marine environments, their sensitivity to environmental changes and their great capacity to fossilize. However, the use of benthic foraminifera as paleoenvironmental proxies requires a good knowledge of the ecological conditions and the parameters controlling species distribution. Although knowledges about the ecology of benthic foraminifera are improving, they remain sporadic in Arctic area, a complex ecosystem characterized by multiple interactions between the atmosphere, the ocean and the cryosphere and particularly sensitive to change and vulnerable to global warming. Temperatures in the Arctic have risen twice as fast as the global average over the past decades, a phenomenon that has been dubbed the “polar amplification of global warming”. In this context, this thesis aims at better understanding the ecology of living benthic foraminifera in Arctic regions and at defining the importance of environmental controls on fauna such as water mass properties, primary productivity, organic matter flux as well as sea-ice dynamics. Living benthic foraminifera were identified in the first centimetres of 21 surface sediment cores collected in three Arctic areas during summer in 2014 and 2015: Baffin Bay and the Barents and Chukchi Seas. These three regions present specific characteristics in terms of sea-ice cover, water mass circulation or primary productivity. Our results suggest that these factors influence the distribution of benthic foraminifera. The flux of organic matter resulting from primary productivity intensified during spring and summer periods near hydrographic polar fronts, sea-ice edges (marginal ice zones) and in the north water polynya (Baffin Bay) increases the fauna’s densities and diversity and favours the development of specific species. Nonionellina labradorica in cold Arctic waters and Cassidulina neoteretis associated with Atlantic waters respond to fresh supply ... Doctoral or Postdoctoral Thesis Arctic Arctique* Baffin Bay Baffin Bay Baffin Barents Sea Chukchi Chukchi Sea Climate change Foraminifera* Global warming Sea ice EPHE (Ecole pratique des hautes études, Paris): HAL |