1. Acoustic Survey of an Estuarine Marine Protected Area and of its Close Vicinity: Analysis and Monitoring Prospective
- Author
-
Béhagle, Nolwenn, Guillard, Jean, Ecoutin, Jean-Marc, Laë, Raymond, Sow, Ibrahima, Tito De Morais, Luis, Lebourges-Dhaussy, Anne, Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), ANR-07-BDIV-0009,AMPHORE,Les aires marines protégées : outil de conservation de la biodiversité et de gestion durable des ressources halieutiques.(2007), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de la Recherche Agronomique (INRA), Centre de Recherche Océanographique de Dakar-Thiaroye (CRODT), and Institut Sénégalais de Recherches Agricoles [Dakar] (ISRA)
- Subjects
geography ,geography.geographical_feature_category ,Estuary ,Marine Protected Areas ,General Medicine ,Oceanography ,Fish ,Hydro-acoustics ,West Africa ,Environmental science ,Marine protected area ,14. Life underwater ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,ACLN ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience; Facing the loss of fish biodiversity and the decrease of fish stocks since several decades, a proposed solution is the multipli-cation of Marine Protected Areas (MPA). In Senegal, one MPA has been implemented in 2003 in one of the channels composing the Sine Saloum estuary. A monitoring program was carried out based on hydro-acoustic survey and the two main metrics extracted from hydro-acoustic data: Fish biomass proxy and fish size distribution proxy. The surveys were performed using vertical beaming at differ-ent seasons from 2003 to 2010. In the MPA, a light increase of the fish biomass proxy and an increase of the fish size proxy during the dry season were observed. The biomass proxy recorded in a close but not protected tributary were higher than in the MPA, probably due to a strong connection with open marine water, aggregative be-havior of preys in the MPA due to higher predation, and a stronger avoidance phenomenon in the MPA. The high variability of the MPA environment submitted to both estuarine and marine influences and the size of the MPA may explain the lack of clear results. However, the learned lessons enable us to make recommendations to monitor fish population in MPAs using hydroacoustic methods. Evaluation procedures using these methods are proposed highlighting the im-portance of a rigorous survey protocol to insure the exploitation of the entire acquired time series.
- Published
- 2018