FN Archimer Export Format PT J TI Comparison of benthic oxygen exchange measured by aquatic Eddy Covariance and Benthic Chambers in two contrasting coastal biotopes (Bay of Brest, France) BT AF Polsenaere, Pierre Deflandre, Bruno Thouzeau, Gerard Rigaud, Sylvain Cox, Tom Amice, Erwan Bec, Thierry Le Bihannic, Isabelle Maire, Olivier AS 1:1,2,3;2:1,2;3:4;4:1,2,5;5:6;6:4;7:4;8:7;9:1,2; FF 1:PDG-ODE-LITTORAL-LERPC;2:;3:;4:;5:;6:;7:;8:;9:; C1 Université de Bordeaux, EPOC, UMR 5805, F-33400 Talence, France CNRS, EPOC, UMR 5805, F-33400 Talence, France IFREMER, Laboratoire Environnement et Ressources des Pertuis Charentais (LER-PC), BP133, 17390, La Tremblade, France LEMAR, UMR 6539 CNRS/UBO/Ifremer/IRD, Technopôle Brest-Iroise, Rue Dumont d’Urville, 29280 Plouzané, France Université de Nîmes, EA 7352 CHROME, Laboratoire de Géochimie Isotopique Environnementale (GIS), 30035 NIMES Cedex 1, France Royal Netherlands Institute for Sea Research (NIOZ), Ecosystem Studies Department, Korringaweg 7, 4401 NT Yerseke, The Netherlands LEMAR, UMR 6539 CNRS/UBO/Ifremer/IRD, Technopôle Brest-Iroise, Rue Dumont d’Urville, 29280 Plouzané, France C2 UNIV BORDEAUX, FRANCE CNRS, FRANCE IFREMER, FRANCE CNRS, FRANCE UNIV NIMES, FRANCE INST SEA RESEARCH (NIOZ), NETHERLANDS UBO, FRANCE SI LA TREMBLADE SE PDG-ODE-LITTORAL-LERPC UM LEMAR IN WOS Ifremer UPR WOS Cotutelle UMR copubli-france copubli-europe copubli-univ-france IF 2.166 TC 4 UR https://archimer.ifremer.fr/doc/00679/79087/81540.pdf LA English DT Article BO Albert Lucas DE ;Benthic O-2 fluxes;Aquatic Eddy Covariance;Benthic Chambers;Maerl bed;Bare mudflat;Bay of Brest AB To the best of our knowledge, the understanding of benthic metabolism of coastal sedimentary areas is still limited due to the complexity of determining their true in situ dynamics over large spatial and temporal scales. Multidisciplinary methodological approaches are then necessary to increase our comprehension of factors controlling benthic processes and fluxes. An aquatic Eddy Covariance (EC) system and Benthic Chambers (BC) were simultaneously deployed during the winter of 2013 in the Bay of Brest within a Maerl bed and a bare mudflat to quantify and compare exchange at the sediment-water interface. Environmental abiotic parameters (i.e., light, temperature, salinity, current velocity and water depth) were additionally monitored to better understand the mechanisms driving benthic exchange. At both sites, EC measurements showed short-term variations (i.e. 15 min) in benthic fluxes according to environmental conditions. At the Maerl station, EC fluxes ranged from -21.0 mmol m−2 d−1 to 71.3 mmol m−2 d−1 and averaged 22.0 ± 32.7 mmol m−2 d−1 (mean SD), whilst at the bare muddy station, EC fluxes ranged from -43.1 mmol m−2 d−1 to 12.1 mmol m−2 d−1 and averaged -15.9 ± 14.0 mmol m−2 d−1 (mean SD) during the total deployment. Eddy Covariance and Benthic Chambers measurements showed similar patterns of temporal flux changes at both sites. However, at the Maerl station, BC may have underestimated community respiration. This may be due to the relative large size of the EC footprint (compared to BC), which takes into account the mesoscale spatial heterogeneity (e.g. may have included contributions from bare sediment patches). Also, we hypothesize that the influence of bioturbation induced by large-sized mobile benthic fauna on sediment oxygen consumption was not fully captured by BC compared to EC. Overall, the results of the present study highlight the importance of taking into account specific methodology limitations with respect to sediment spatial macro-heterogeneity and short-term variations of environmental parameters to accurately assess benthic exchange in the various benthic ecosystems of the coastal zone. PY 2021 PD MAR SO Regional Studies In Marine Science SN 2352-4855 PU Elsevier BV VL 43 UT 000630606600001 DI 10.1016/j.rsma.2021.101668 ID 79087 ER EF