Spatiotemporal dynamics of surface sediment characteristics and benthic macrofauna compositions in a temperate high-energy River-dominated Ocean Margin

• Published in: Continental Shelf Research
• Main Authors: Lamarque, Bastien, Deflandre, Bruno, Schmidt, Sabine, Bernard, Guillaume, Dubosq, Nicolas, Diaz, Melanie, Lavesque, Nicolas, Garabetian, Frederic, Grasso, Florent, Sottolichio, Aldo, Rigaud, Sylvain, Romero-Ramirez, Alicia, Cordier, Marie-Ange, Poirier, Dominique, Danilo, Martin, Gremare, Antoine
• Other Authors: 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), Dynamiques des Écosystèmes Côtiers (DYNECO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Dynamique Hydro-sédimentaire (DHYSED), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Détection, évaluation, gestion des risques CHROniques et éMErgents (CHROME) / Université de Nîmes (CHROME), Université de Nîmes (UNIMES), Bastien Lamarque was partly supported by a doctoral grant from the French “Ministère de l’Enseignement Supérieur, de la Recherche et de l’Innovation”. This work was supported by: (1) the JERICO-NEXT project (European Union's Horizon 2020 Research and Innovation program under grant agreement no. 654410), (2) the VOG project (LEFE-CYBER and EC2CO-PNEC), and (3) the MAGMA project (COTE cluster of Excellence ANR-10-LABX-45). It also benefited from additional fundings allocated by the Conseil Régional Nouvelle-Aquitaine and the Office Français de la Biodiversité. Operations at sea were funded by the French Oceanographic Fleet., ANR-10-LABX-0045,COTE,COntinental To coastal Ecosystems: evolution, adaptability and governance(2010), European Project: 654410,H2020,H2020-INFRAIA-2014-2015,JERICO-NEXT(2015)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: West gironde mud patch; Benthic macrofauna; Hydrodynamics; North-East Atlantic shelf; Particulate organic matter; RiOMar; Spatiotemporal changes; Storms; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; North East Atlantic
• Online Access: https://hal.science/hal-03866642; https://hal.science/hal-03866642/document; https://hal.science/hal-03866642/file/2022_Lamarque_Rigaud_ContiShRes_Postpr_dep.pdf; https://doi.org/10.1016/j.csr.2022.104833

International audience The benthic compartment of River-dominated Ocean Margins (RiOMar) is largely affected by sedimentary processes, as well as by natural and anthropogenic disturbances. Recent studies have confirmed the major importance of riverine inputs and local hydrodynamics in the spatial structuration of low- and high-energy temperate RiOMar, respectively. Differences in the nature of these structuring factors could also affect the temporal dynamics of these two types of systems. The present study is aiming at: (1) quantifying spatiotemporal changes in surface sediment and benthic macrofauna within the West Gironde Mud Patch (WGMP; high-energy system) over both short (2016–2018) and longer (2010/2016–2018) time scales, (2) identifying the main environmental factors explaining those changes, and (3) achieving a comparison with the Rhône River Prodelta (RRP; low-energy system) in view of further characterizing the functioning of the benthic components of these two temperate RiOMar. Surface sediment characteristics (grain size, quantitative and qualitative descriptors of particulate organic matter) and benthic macrofauna compositions were assessed based on 4 seasonal sampling of 5 stations located along a depth gradient within the WGMP. Results highlighted the existence of spatial patterns for both surface sediment and benthic macrofauna, which are both better explained by local hydrodynamics. Most variables presented seasonal changes. Benthic macrofauna compositions also showed pluri-annual changes, which were attributed to a cicatrization process following a major disturbance caused by the 2013–2014 series of severe winter storms, and suggests the major role of local hydrodynamics in explaining 2010/2016–2018 temporal changes in WGMP benthic macrofauna compositions. The comparison with the RRP further highlighted major discrepancies between the two systems in the main processes (i.e., hydrodynamics versus river hydrological regime) explaining surface sediment characteristics and benthic macrofauna ...