Modeling trophic interactions to assess the effects of a marine protected area: case study in the NW Mediterranean Sea

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 456:201-214 (2012) - DOI: https://doi.org/10.3354/meps09701 Modeling trophic interactions to assess the effects of a marine protected area: case study in the NW Mediterranean Sea Audrey Valls1,3,*, Didier Gascuel1, Sylvie Guénette1, Patrice Francour2 1Université Européenne de Bretagne, Pôle halieutique Agrocampus Ouest, UMR 985 Ecologie et Santé des Ecosystèmes, CS 84215, 35042 Rennes cedex, France 2Université de Nice Sophia-Antipolis, Faculté des Sciences, EA 4228 ECOMERS, 06108 Nice cedex 2, France 3Present address: University of British Columbia, AERL, Fisheries Centre, Vancouver, British Columbia V6T1Z4, Canada *Email: a.valls@fisheries.ubc.ca ABSTRACT: The present study describes the food web and evaluates the effects of a marine protected area (MPA), the Port-Cros National Park (NW Mediterranean Sea), on the marine ecosystem inside the reserve and its potential to sustain resources outside the reserve. We built an Ecopath model of the Port-Cros MPA which comprised 41 functional groups and represented an average situation for the period 1998 to 2008. At a high trophic level, fish were dominated by the amberjacks and large dusky grouper groups, 2 abundant top predators playing a central role in the ecosystem in terms of keystone species and trophic cascades. The biomass accumulation rate estimated with Ecopath could reach 10% yr−1 for large dusky groupers, which is consistent with field observations, suggesting that the MPA succeeded in protecting the species. The total export from the MPA was estimated at a maximum of about 100 tons yr−1, which limits the benefits at a local scale. EcoTroph fishing scenarios showed that the current state of the ecosystem inside the reserve was close to the unexploited state, and that current fishing practices had an insignificant impact. The major effects of the MPA were to protect the high trophic level groups and thus to maintain the functional biodiversity within the reserve. In summary, trophic modeling seems to be a relevant approach to study the effects of MPAs and to improve their management. KEY WORDS: Ecosystem modeling · Reserve effect · Fishing impact · Ecopath · EcoTroph · Keystone species · Biomass export · Port-Cros · Mediterranean Sea Full text in pdf format Supplementary material PreviousNextCite this article as: Valls A, Gascuel D, Guénette S, Francour P (2012) Modeling trophic interactions to assess the effects of a marine protected area: case study in the NW Mediterranean Sea. Mar Ecol Prog Ser 456:201-214. https://doi.org/10.3354/meps09701 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 456. Online publication date: June 07, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.