FN Archimer Export Format PT C TI Assessment and quantification of the anthropic impact on the posidonia oceanica seagrass meadow BT AF ALAMI, Sami BONACORSI, Marina CLABAUT, Philippe JOUET, Gwenael PERGENT-MARTINI, Christine PERGENT, Gerard STERCKEMAN, Aurore AS 1:;2:;3:;4:;5:;6:;7:; FF 1:;2:;3:;4:PDG-REM-GM-LES;5:;6:;7:; SI AUTRE BREST SE AUTRE PDG-REM-GM-LES AIRES MARINES UR https://archimer.ifremer.fr/doc/00272/38364/36669.pdf LA English DT Proceedings paper CR CAPCORAL CAPCORAL 2 BO L'Europe DE ;Anthropogenic impact;Corsica;Side Scan Sonar;Posidonia oceanica;trawling AB The regression of seagrass meadows has been extensively studied over the past few years. Although the causes of this regression may be locally natural, it is more generally related to human impact. In the framework of the HalGolo (2010) and CoralCorse (2013) oceanographic campaigns, acoustic data (mosaic of sonograms and bathymetry), validated by field data (Scuba diving, ROV), were acquired at depths of -10 m and -50 m at the NATURA 2000 site “Grand Herbier de la Plaine Orientale” (Western Mediterranean, Corsica). Processing of this data provided evidence of the scale of this mechanical degradation (trawling scars, mooring, etc.), and enabled its quantification with regard to surface area and scar density. The main degradation was observed between -20 and – 40 m depth (98%); the surface area of seagrass meadow destroyed is estimated at 280 ha with more than 40 scars per hectare recorded in the northern part of the site. Given the slow growth rate of the meadow, assuming the hypothesis of the ending of these practices, it would require almost 150 years to recover these scars. PY 2015 CT UNEP/MAP – RAC/SPA, 2015. Proceedings of the 5th Mediterranean Symposium on Marine Vegetation (Portorož, Slovenia, 27-28 October 2014). LANGAR H., BOUAFIF C., OUERGHI A., edits., RAC/SPA publ., Tunis: 264 p. ISBN 978-9938-9574-0-2.. pp.34-39 / PNUE/PAM – CAR/ASP, 2015. Actes du 5ème Symposium Méditerranéen sur la Végétation Marine (Portorož, Slovénie, 27-28 octobre 2014). LANGAR H., BOUAFIF C., OUERGHI A., édits., CAR/ASP publ., Tunis :264 p. pp.34-39 ID 38364 ER EF