Spatial assessment of benefits of a coastal Mediterranean Marine Protected Area

  • Published source details Stelzenmüller V., Maynou F. & Martín P. (2008) Spatial assessment of benefits of a coastal Mediterranean Marine Protected Area. Biological Conservation, 136, 571-583.


In some areas, marine reserves are advocated to conserve biodiversity and enhance local coastal fisheries, but evidence of their benefits is often lacking; seasonal changes in fish populations and habitat variation often confound data interpretation. In this study the benefits of the Medes Island Marine Reserve was undertaken by analysing and modelling the effects of trends reflecting habitat heterogeneity and spatial structuring of data on predictions of fish catch per unit effort (CPUE) and length.

Study area: The study took place off the Medes Islands Marine Reserve (established in 1983), a small archipelago located 1 km offshore of the town of L'Estartit (42ºN, 03ºE) on the Costa Brava, northeast Spain. It consists of a 91 ha Integral Reserve (fishing banned in 1991), and a Buffer Zone (418 ha) where only artisanal fishing by 24 small (c.6.5 m) boats is allowed. The study area included the MPA, a zone with artificial reefs (established to ensure exclusion of trawl-fishing from adjacent waters), and sea grass Posidonia oceanica meadows.

The most often employed fishing gears used by the artisanal fishery were trammel nets, gillnets, and longlines, which focus on seven main target fish species. Two of these, striped red mullet Mullus surmuletus and common pandora Pagellus erythrinus were the focus of this study.

Data collection: In March-December 2003 to 2005, daily data was collated on catch composition, fish length, catch position, fishing gear, depth and substrate from seven representative vessels that fished regularly within the vicinity of the Reserve.

CPUE of total fish and CPUE and length of common pandora increased close to the Integral Reserve this attributed to direct and indirect effects of the marine reserve. CPUE and length of striped red mullet also increased near the Integral Reserve, but only slightly so, but distinct reserve effects could not be identified due to the influence of artificial reefs.

The authors conclude that the Buffer Zone, where artisanal fisheries are allowed (as opposed to commercial trawling), afforded some protection to the two target fish species studied.

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