Résumé: Adult and juvenile mobility has a considerable influence on the functioning of marine protected areas. It is recognized that adult and juvenile movement reduces the core benefits of protected areas, namely protecting the full age-structure of marine populations, while at the same time perhaps improving fisheries yield over the no-reserve situation through export of individuals from protected areas. Nevertheless, the study of the consequences of movement on protected area functioning is unbalanced. Significant attention has been paid to the influence of certain movement patterns, such as diffusive movement and home ranges, while the impacts of others, such as density-dependent movements and ontogenetic migrations, have been relatively ignored. Here we review the diversity of density-independent and density-dependent movement patterns, as well as what is currently known about their consequences for the conservation and fisheries effects of marine protected areas. We highlight a number of 'partially addressed' issues in marine protected area research, such as the effects of reserves targeting specific life phases, and a number of essentially unstudied issues, such as density-dependent movements, nomadism, ontogenetic migrations, behavioral polymorphism and 'dynamic' reserves that adjust location as a realtime response to habitat changes. Assessing these issues will be essential to creating effective marine protected area networks for mobile species and accurately assessing reserve impacts on these species.

Résumé: Marine reserves are expected to benefit a wide range of species, but most models used to evaluate their effects assume that adults are sedentary, thereby potentially overestimating population persistence. Many nearshore marine organisms move within a home range as adults, and there is a need to understand the effects of this type of movement on reserve performance. We incorporated movement within a home range into a spatially explicit marine reserve model in order to assess the combined effects of adult and larval movement on persistence and yield in a general, strategic framework. We describe how the capacity of a population to persist decreased with increasing home range size in a manner that depended on whether the sedentary case was maintained by self persistence or network persistence. Self persistence declined gradually with increasing home range and larval dispersal distance, while network persistence decreased sharply to 0 above a threshold home range and was less dependent on larval dispersal distance. The maximum home range size protected by a reserve network increased with the fraction of coastline in reserves and decreasing exploitation rates outside reserves. Spillover due to movement within a home range contributed to yield moderately under certain conditions, although yield contributions were generally not as large as those from spillover due to larval dispersal. Our results indicate that, for species exhibiting home range behavior, persistence in a network of marine reserves may be more predictable than previously anticipated from models based solely on larval dispersal, in part due to better knowledge of home range sizes. Including movement within a home range can change persistence results significantly from those assuming that adults are sedentary; hence it is an important consideration in reserve design.

Résumé: Marine 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 multiple-use 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.