Influence of oyster culture practices and environmental conditions on the ecological status of intertidal mudflats in the Pertuis Charentais (SW France): A multi-index approach

• Published in: Marine Pollution Bulletin
• Main Authors: Bouchet, Vincent M.P., Sauriau, Pierre-Guy
• Other Authors: Bio-Indicateurs Actuels et Fossiles (BIAF), Université d'Angers (UA), Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG), Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche sur les Ecosystèmes Littoraux Anthropisés (CRELA), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Angers Agglomération, CNRS, IFREMER
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: Oyster farming practices; Intertidal mudflats; Biotic index; Benthic macrofauna; Seasonal variations; Exposed/sheltered; envir; geo; Pacific; Pacific oyster
• Online Access: https://doi.org/10.1016/j.marpolbul.2008.07.010; https://hal.archives-ouvertes.fr/hal-01855367

International audience The ecological quality status (EcoQ) of intertidal mudflats constrained by Pacific oyster farming was assessed by single (H’, AMBI, BENTIX and BOPA) and multimetric (M-AMBI and average score) index approaches in the Pertuis Charentais (SW France). Fifteen sampling stations were monitored seasonally for sedimentological features and macrozoobenthos in 2004. Sediments affected by oyster biodeposits showed organic matter enrichment, and sediments from off-bottom culture sites had higher organic matter contents and lower redox potentials than sediments from on-bottom culture sites. Biotic indices consistently registered responses of macrozoobenthos to organic enrichment but there was only partial agreement between single index-derived EcoQs. The average score was better than M-AMBI and single indices for determining EcoQs. Accordingly, oyster farming alters intertidal macrozoobenthic assemblages moderately, and off-bottom cultures cause more disturbance than on-bottom cultures. Hydrodynamics and seasons may interact with culture practices in smothering/strengthening biodeposition-mediated effects through dispersal/accumulation of biodeposits.