Benefits for fisheries from marine protected areas (MPAs) are expected from recruitment of exported eggs and larvae as well as from spillover of adults to adjacent fishing grounds. Because the recruitment effect is difficult to detect, spillover is presently the only tangible potential fishery benefit of MPAs. Despite abundant evidence of spillover in the literature, this is the first study to quantify the number and biomass of individuals annually spilling over from an MPA and their contribution to the local fishery catches. Using a decade (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)) of tag-recapture data for the lobster Palinurus elephas from the Columbretes Islands Marine Reserve (CIMR), we estimated annual emigration probabilities of 3.7% (female) and 6.7% (male), and quantified the resulting spillover to adjacent fished areas. We showed that during an 8 to 17 yr protection period, harvested spillover offset the loss of yield resulting from the reduction of fishing grounds set aside in the CIMR, producing a mean annual net benefit of 10% of the catch in weight. Although the number of lobsters spilling over annually did not quite make up for the loss of fishing grounds in the CIMR, it did in weight because the mean size of the lobsters emigrating from the reserve was larger than that of those outside. We propose that nomadic or home range movements of individuals near MPA boundaries, seasonal migrations and migrations forced by extraordinary meteorological events, and density-dependent movements facilitated spillover from the CIMR. Fishing effort concentration along its boundaries and high exploitation rates in the local fishery limited the spatial extent of spillover.

ABSTRACT:We assessed the development of the exploited fish community inside and around the Columbretes Islands Marine Reserve (CIMR), a marine protected area (MPA), 8 to 16 yr after fishing ceased in the reserve. Sampling was by annual lobster trammel net fishing, an experimental technique used inside the CIMR, and on-board commercial operations in adjacent fishing grounds. We examined trends in combined fish abundance and biomass (catch per unit effort), species richness and diversity, size structure, trophic level and species composition of the community. Our results showed the CIMR fish community continued to change throughout the study period as (1) abundance and biomass increased, (2) mean body size and trophic level increased and (3) species composition changed according to a linear model. Relative to nearby fished areas the CIMR fish community had (1) higher abundance and biomass, (2) lower species diversity and higher taxonomic distinctness, (3) larger relative body size and (4) no difference in mean trophic level. We found clear evidence of spillover of fish from the CIMR to the adjacent fishery as commercial fish yields at the MPA border (< 0.5 km from the boundary) increased continuously during the study period, despite being locally depleted due to fishing effort concentration (fishing the line). Furthermore, fish size and diversity at the border were intermediate between the CIMR and other fished zones, suggesting that this is a transitional zone influenced by this MPA. Our results show that changes in community abundance, biomass, size structure and species composition provide a clear and interpretable view of MPA recovery. Diversity indices are also useful; however, their interpretation is more difficult. We conclude that the creation of the CIMR has had a positive effect on the exploitable fish community and that there is evidence of exportation of biomass to the surrounding fishery. We highlight the advantage of using multiple community metrics to study changes in fish communities, yet recommend the need for caution when interpreting them.

Long-distance (>40km) dispersal from marine reserves is poorly documented. Yet, it can provide essential benefits such as seedling fished areas or connecting marine reserves into networks. From a meta-analysis, we suggest that the spatial scale of marine connectivity is underestimated due to the limited geographic extent of sampling designs. We also found that the largest marine reserves (>1,000km 2 ) are the most isolated. These findings have important implications for the assessment of evolutionary, ecological and socio-economic long-distance benefits of marine reserves. We conclude that existing methods to infer dispersal should consider the up-to-date genomic advances and also expand the spatial scale of sampling designs. Incorporating long-distance connectivity in conservation planning will contribute to increase the benefits of marine reserve networks.

2Marine protected areas (MPAs) are key tools to mitigate human impacts in coastal environments, promoting sustainable activities to conserve biodiversity. The designation of MPAs alone may not result in the lessening of some human threats, which is highly dependent on management goals and the related specific regulations that are adopted. Here, we develop and operationalize a local threat assessment framework. We develop indices to quantify the effectiveness of MPAs (or individual zones within MPAs in the case of multipleuse MPAs) in reducing anthropogenic extractive and non-extractive threats operating at local scale, focusing specifically on threats that can be managed through MPAs. We apply this framework in 15 Mediterranean MPAs to assess their threat reduction capacity. We show that fully protected areas effectively eliminate extractive activities, whereas the intensity of artisanal and recreational fishing within partially protected areas, paradoxically, is higher than that found outside MPAs, questioning their ability at reaching conservation targets. In addition, both fully and partially protected areas attract non-extractive activities that are potential threats. Overall, only three of the 15 MPAs had lower intensities for the entire set of eight threats considered, in respect to adjacent control unprotected areas. Understanding the intensity and occurrence of human threats operating at the local scale inside and around MPAs is important for assessing MPAs effectiveness in achieving the goals they have been designed for, informing management strategies, and prioritizing specific actions.Keywords: fully protected area; partially protected area; management; extractive activities; non-extractive activities; marine use; Highlights• We present and operationalize a cost-effective framework to quantify local threats inside and outside MPAs.• We assess how good MPAs are at curbing extractive and non-extractive threats.• Fully protected areas effectively eliminate extractive threats.• Fully protected areas attract non-extractive threats, when allowed.• Small scale fishing intensity is larger in partially protected areas than outside.3

How far do marine larvae disperse in the ocean? Decades of population genetic studies have revealed generally low levels of genetic structure at large spatial scales (hundreds of kilometres). Yet this result, typically based on discrete sampling designs, does not necessarily imply extensive dispersal. Here, we adopt a continuous sampling strategy along 950 km of coast in the northwestern Mediterranean Sea to address this question in four species. In line with expectations, we observe weak genetic structure at a large spatial scale. Nevertheless, our continuous sampling strategy uncovers a pattern of isolation by distance at small spatial scales (few tens of kilometres) in two species. Individual-based simulations indicate that this signal is an expected signature of restricted dispersal. At the other extreme of the connectivity spectrum, two pairs of individuals that are closely related genetically were found more than 290 km apart, indicating long-distance dispersal. Such a combination of restricted dispersal with rare long-distance dispersal events is supported by a high-resolution biophysical model of larval dispersal in the study area, and we posit that it may be common in marine species. Our results bridge population genetic studies with direct dispersal studies and have implications for the design of marine reserve networks.