Does coastal lagoon habitat quality affect fish growth rate and their recruitment? Insights from fishing and acoustic surveys Auteur(s) : Brehmer, Patrice Laugier, Thierry Kantoussan, J. Galgani, Francois Mouillot, D. Éditeur(s) : Academic Press Ltd- Elsevier Science Ltd Résumé : Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was not an indicator of habitat quality, whereas Atherina boyeri and Sparus aurata appeared to be more sensitive to habitat quality. Fish abundance was higher in the two lagoons with high eutrophication and ecotoxicity levels than in the less impacted lagoon, while fish sizes were significantly higher in the two most severely impacted lagoons. This leads us to suggest low habitat quality may increase fish growth rate (by the mean of a cascading effect), but may reduce lagoon juvenile abundance by increasing larval mortality. Such a hypothesis needs to be further validated using greater investigations which take into account more influences on fish growth and recruitment in such variable environments under complex multi-stressor conditions. Estuarine Coastal And Shelf Science (0272-7714) (Academic Press Ltd- Elsevier Science Ltd), 2013-07 , Vol. 126 , P. 1-6 Droits : 2013 Elsevier Ltd. All rights reserved http://archimer.ifremer.fr/doc/00148/25963/24083.pdf DOI:10.1016/j.ecss.2013.03.011 http://archimer.ifremer.fr/doc/00148/25963/ | Partager |
Field investigations and multi-indicators for shallow water lagoon management: perspective for societal benefit Auteur(s) : Brehmer, Patrice Thang Do Chi, Laugier, Thierry Galgani, Francois Laloe, Francis Darnaude, Audrey M. Fiandrino, Annie Mouillot, David Éditeur(s) : Wiley-blackwell Résumé : 1. Abiotic and biotic variables of coastal lagoons are highly heterogeneous in both space and time, and this heterogeneity complicates the assessment of their ecological status. These variables are essential to the monitoring and preservation of these fragile ecotones and the resources and services they sustain. 2. An integrative approach for evaluating the ecological status of coastal lagoons, based on field investigations of the key parameters driving their functioning and a set of selected ecological indicators matching lagoon management information needs for societal benefits, is investigated. Consistency in lagoon status evaluation from multiple and different variables was estimated, through a case study comparing three adjacent yet contrasting French Mediterranean shallow water lagoons. 3. French Mediterranean shallow water lagoons are used to demonstrate the potential of such an approach and to underline the need for a multi-faceted framework, for correctly evaluating lagoon status, and underlining the need for high-frequency lagoon monitoring to avoid errors in status assessment and resulting management plans. 4. Based on the results, a continuous monitoring system is proposed that would record high frequency biotic and abiotic data in the lagoons. The use of such an ad hoc observatory system, based on appropriate diagnostic indicators and risk estimators would simplify interactions between scientists and managers and would improve the efficiency of their analyses. 5. A lagoon management plan based on a holistic approach is proposed to help scientists and local managers to reach a consensus about the set of ecological indicators to monitor in the lagoons needed to assess their global health status in accordance with both conservation and/or societal needs. Copyright (c) 2011 John Wiley & Sons, Ltd. Aquatic Conservation-marine And Freshwater Ecosystems (1052-7613) (Wiley-blackwell), 2011-11 , Vol. 21 , N. 7 , P. 728-742 Droits : 2011 John Wiley & Sons, Ltd. http://archimer.ifremer.fr/doc/00056/16702/14202.pdf DOI:10.1002/aqc.1231 http://archimer.ifremer.fr/doc/00056/16702/ | Partager Voir aussi coastal lagoon ecological assessment ecotoxicology eutrophication indicator management Mediterranean Sea observatory Télécharger |