ABSTRACT: Multiple-use marine protected areas (MPAs) are used to manage marine resources, allocate space to different users and reduce
conflicts while protecting marine biodiversity. In the Mediterranean, MPA managers are increasingly interested in containing
the effects of coastal recreation within underwater trails, but snorkelers impacts on the surrounding ecosystem remain largely
unknown. In a Mediterranean MPA, an underwater snorkeling trail was established to concentrate snorkelers and increase their
awareness of marine habitats and species. The high level of summer frequentation may have negative impacts on the surrounding
environment through trampling on the sessile flora or disturbance to the vagile fauna. We used a before-after-control-impact
(BACI) design to analyse these potential human impacts. The structure of macroalgae and fish assemblages were used as indicators.
Permutational multivariate analyses of variance (PERMANOVA) were carried out to assess potential temporal and spatial changes
of the indicators between the trail and a control location within the adjacent no-take/no-use area. Fish communities and macroalgae
were subjected to natural temporal trends but no significant impacts of snorkelers were found. Four reasons could explain
the absence of snorkelers impact on the surrounding marine environment: (1) the absence of very fragile organisms within the
trail (and the control no-take/no-use area) such as gorgonians or bryozoans; (2) the life cycle of the algae with a natural
decreasing trend in summer, corresponding to the trail opening period; (3) only a few snorkelers are practicing apnoea; and
(4) the information at the entrance and along the trail may influence the snorkelers’ behaviour.
KeywordsCoastal management-Human impact-Impact assessment-Indicator-Marine protected area (MPA)-Marine reserve-Mediterranean Sea-Recreational impact-Recreational uses
Biodiversity and Conservation 04/2012; 19(6):1649-1658. · 2.24 Impact Factor
ABSTRACT: The links between species-environment relations and species' responses to protection are unclear, but the objectives of marine protected areas (MPAs) are most likely to be achieved when those relations are known and inform MPA design. The components of a species' habitat vary with the spatial resolution of the area considered. We characterized areas at two resolutions: 250 m(2) (transect) and approximately 30,000 m(2) (seascape). We considered three categories of environmental variables: substrate type, bottom complexity, and depth. We sought to determine at which resolution habitat characteristics were a better predictor of abundance and species composition of fishes and whether the relations with environmental variables at either resolution affected species' responses to protection. Habitat features accounted for a larger proportion of spatial variation in species composition and abundances than differences in protection status. This spatial variation was explained best by habitat characteristics at the seascape level than at the transect level. Species' responses to protected areas were specific to particular seascape characteristics, primarily depth, and bottom complexity. Our method may be useful for prioritizing marine areas for protection, designing MPAs, and monitoring their effectiveness. It identified areas that provided natural shelter, areas acting as buffer zones, and areas where fish species were most responsive to protection. The identification of such areas is necessary for cost-effective establishment and monitoring of MPAs.
Conservation Biology 10/2010; 25(1):105-14. · 4.69 Impact Factor
Nature 04/2010; 464(7289):673. · 36.28 Impact Factor
Aquatic Conservation Marine and Freshwater Ecosystems 12/2009; 20(2):239 - 242. · 1.93 Impact Factor
ABSTRACT: Fishing activities worldwide have dramatically affected marine fish stocks and ecosystems. Marine protected areas (MPAs) with no-take zones may enhance fisheries, but empirical evidence of this is scant. We conducted a 4-year survey of fish catches around and within an MPA that was previously fully closed to fishing and then partially reopened under regulated comanaged fishing. In collaboration with the fishers and the MPA authority, we set the fishing effort and selected the gear to limit fishing impact on key fish predators, juvenile fish stage, and benthic communities and habitats. Within an adaptive comanagement framework, fishers agreed to reduce fishing effort if symptoms of overfishing were detected. We analyzed the temporal trends of catch per unit of effort (CPUE) of the whole species assemblages and CPUE of the four most valuable and frequent species observed inside the opened buffer zone and outside the MPA investigated. After the comanaged opening, CPUE first declined and then stabilized at levels more than twice that of catches obtained outside the MPA. Our results suggest that working closely with fishers can result in greater fisheries catches. Partial protection of coastal areas together with adaptive comanagement involving fishers, scientists, and managers can effectively achieve conservation and fishery management goals and benefit fishing communities and alleviate overfishing.
Conservation Biology 11/2009; 24(1):312-8. · 4.69 Impact Factor
ABSTRACT: Marine reserves are widely used throughout the world to prevent overfishing and conserve biodiversity, but uncertainties remain about their optimal design. The effects of marine reserves are heterogeneous. Despite theoretical findings, empirical studies have previously found no effect of size on the effectiveness of marine reserves in protecting commercial fish stocks. Using 58 datasets from 19 European marine reserves, we show that reserve size and age do matter: Increasing the size of the no-take zone increases the density of commercial fishes within the reserve compared with outside; whereas the size of the buffer zone has the opposite effect. Moreover, positive effects of marine reserve on commercial fish species and species richness are linked to the time elapsed since the establishment of the protection scheme. The reserve size-dependency of the response to protection has strong implications for the spatial management of coastal areas because marine reserves are used for spatial zoning.
Ecology Letters 06/2008; 11(5):481-9. · 17.56 Impact Factor