Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment
International audience Foraminiferal mudflat communities in the Auray estuary, located along the French Northwest Atlantic coast, were investigated in September 2020. Numerous living specimens of calcareous species showed marks of dissolution. The number of affected individuals, together with their...
Published in: | Comptes Rendus. Géoscience |
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Main Authors: | , , , , |
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Language: | English |
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HAL CCSD
2024
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Online Access: | https://hal.science/hal-04634736 https://hal.science/hal-04634736/document https://hal.science/hal-04634736/file/crgeos20240215.pdf https://doi.org/10.5802/crgeos.269 |
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Institut national des sciences de l'Univers: HAL-INSU |
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English |
topic |
Benthic foraminifera Cable bacteria Test preservation Sediment acidification proxy [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Benthic foraminifera Cable bacteria Test preservation Sediment acidification proxy [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Fouet, Marie Daviray, Maxime Geslin, Emmanuelle Metzger, Edouard Jorissen, Frans Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
topic_facet |
Benthic foraminifera Cable bacteria Test preservation Sediment acidification proxy [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Foraminiferal mudflat communities in the Auray estuary, located along the French Northwest Atlantic coast, were investigated in September 2020. Numerous living specimens of calcareous species showed marks of dissolution. The number of affected individuals, together with their dissolution degree, varied from one site to another. Moreover, pH profiles showed porewater acidification of the subsurface sediment at several stations. We propose two metrics quantifying the degree of dissolution: (i) the “Foraminiferal Test Dissolution” (FTD), based on binocular observations of the foraminiferal community, and (ii) the “Calcareous Test Preservation Ratio” (CTPR), surface ratio (0– 0.5 cm) of total living foraminiferal densities (0–1 cm). In stations showing sediment acidification, the O2-pH profiles show the typical biogeochemical signatures of cable bacteria activity (pH increase in the oxic zone followed by strong acidification in the suboxic zone). This suggests that bacterial activity could be responsible for the strong pH decrease leading to corrosive porewaters affecting calcareous tests, hence severe FTD in the first centimetre of sediment leading to high CTPR. Furthermore, observations of FTD in other estuaries on the French Atlantic coast indicate that the phenomenon has becomewidespread. Re-investigated foraminiferal tests sampled in 1995–1996 in the Auray estuary show no dissolution marks, suggesting that the dissolution process observed in 2020 appeared over the last thirty years. Therefore, the FTD and CTPR could be used as rapid tools to establish the occurrence of dissolution processes, pending geochemical confirmation. The FTD could also be used as sediment acidification proxy in historical records, where geochemical analyses are not possible. |
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) Laboratoire de Planétologie et Géosciences - Angers (LPG-ANGERS) Laboratoire de Planétologie et Géosciences UMR_C 6112 (LPG) Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST) Nantes Université - pôle Sciences et technologie Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST) Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ) Funding from the CNRS-INSU (program LEFE-CYBER, project CB-FOR), from the Angers University and the OFB (French Office of Biodiversity, grant number 3976-CT-RD-AMI-18-SURV-FORESTAT). |
format |
Article in Journal/Newspaper |
author |
Fouet, Marie Daviray, Maxime Geslin, Emmanuelle Metzger, Edouard Jorissen, Frans |
author_facet |
Fouet, Marie Daviray, Maxime Geslin, Emmanuelle Metzger, Edouard Jorissen, Frans |
author_sort |
Fouet, Marie |
title |
Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
title_short |
Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
title_full |
Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
title_fullStr |
Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
title_full_unstemmed |
Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
title_sort |
foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment |
publisher |
HAL CCSD |
publishDate |
2024 |
url |
https://hal.science/hal-04634736 https://hal.science/hal-04634736/document https://hal.science/hal-04634736/file/crgeos20240215.pdf https://doi.org/10.5802/crgeos.269 |
genre |
Northwest Atlantic |
genre_facet |
Northwest Atlantic |
op_source |
ISSN: 1631-0713 EISSN: 1778-7025 Comptes Rendus. Géoscience https://hal.science/hal-04634736 Comptes Rendus. Géoscience, 2024, 356, pp.83-96. ⟨10.5802/crgeos.269⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5802/crgeos.269 hal-04634736 https://hal.science/hal-04634736 https://hal.science/hal-04634736/document https://hal.science/hal-04634736/file/crgeos20240215.pdf doi:10.5802/crgeos.269 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5802/crgeos.269 |
container_title |
Comptes Rendus. Géoscience |
container_volume |
356 |
container_issue |
G1 |
container_start_page |
83 |
op_container_end_page |
96 |
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1810466896466673664 |
spelling |
ftinsu:oai:HAL:hal-04634736v1 2024-09-15T18:26:24+00:00 Foraminiferal test dissolution reveals severe sediment acidification in estuarine mudflats: new perspectives for present and historical assessment La dissolution de tests de foraminifères révèle une acidification sévère des sédiments dans les vasières estuariennes : nouvelles perspectives pour l’évaluation actuelle et historique Fouet, Marie Daviray, Maxime Geslin, Emmanuelle Metzger, Edouard Jorissen, Frans 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) Laboratoire de Planétologie et Géosciences - Angers (LPG-ANGERS) Laboratoire de Planétologie et Géosciences UMR_C 6112 (LPG) Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST) Nantes Université - pôle Sciences et technologie Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST) Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ) Funding from the CNRS-INSU (program LEFE-CYBER, project CB-FOR), from the Angers University and the OFB (French Office of Biodiversity, grant number 3976-CT-RD-AMI-18-SURV-FORESTAT). 2024 https://hal.science/hal-04634736 https://hal.science/hal-04634736/document https://hal.science/hal-04634736/file/crgeos20240215.pdf https://doi.org/10.5802/crgeos.269 en eng HAL CCSD Académie des sciences (Paris) info:eu-repo/semantics/altIdentifier/doi/10.5802/crgeos.269 hal-04634736 https://hal.science/hal-04634736 https://hal.science/hal-04634736/document https://hal.science/hal-04634736/file/crgeos20240215.pdf doi:10.5802/crgeos.269 info:eu-repo/semantics/OpenAccess ISSN: 1631-0713 EISSN: 1778-7025 Comptes Rendus. Géoscience https://hal.science/hal-04634736 Comptes Rendus. Géoscience, 2024, 356, pp.83-96. ⟨10.5802/crgeos.269⟩ Benthic foraminifera Cable bacteria Test preservation Sediment acidification proxy [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2024 ftinsu https://doi.org/10.5802/crgeos.269 2024-07-11T14:05:57Z International audience Foraminiferal mudflat communities in the Auray estuary, located along the French Northwest Atlantic coast, were investigated in September 2020. Numerous living specimens of calcareous species showed marks of dissolution. The number of affected individuals, together with their dissolution degree, varied from one site to another. Moreover, pH profiles showed porewater acidification of the subsurface sediment at several stations. We propose two metrics quantifying the degree of dissolution: (i) the “Foraminiferal Test Dissolution” (FTD), based on binocular observations of the foraminiferal community, and (ii) the “Calcareous Test Preservation Ratio” (CTPR), surface ratio (0– 0.5 cm) of total living foraminiferal densities (0–1 cm). In stations showing sediment acidification, the O2-pH profiles show the typical biogeochemical signatures of cable bacteria activity (pH increase in the oxic zone followed by strong acidification in the suboxic zone). This suggests that bacterial activity could be responsible for the strong pH decrease leading to corrosive porewaters affecting calcareous tests, hence severe FTD in the first centimetre of sediment leading to high CTPR. Furthermore, observations of FTD in other estuaries on the French Atlantic coast indicate that the phenomenon has becomewidespread. Re-investigated foraminiferal tests sampled in 1995–1996 in the Auray estuary show no dissolution marks, suggesting that the dissolution process observed in 2020 appeared over the last thirty years. Therefore, the FTD and CTPR could be used as rapid tools to establish the occurrence of dissolution processes, pending geochemical confirmation. The FTD could also be used as sediment acidification proxy in historical records, where geochemical analyses are not possible. Article in Journal/Newspaper Northwest Atlantic Institut national des sciences de l'Univers: HAL-INSU Comptes Rendus. Géoscience 356 G1 83 96 |