Human-induced disturbance, e.g., through unsustainable fishery activities, can affect the ecology of coastal areas (Jackson et al., 2001; Lotze et al., 2006) and reduce the associated goods and services required for human welfare (Worm et al., 2006). Major concerns are rising over observed declines in the abundance of particular species as well as reductions in functional diversity and changes in food web structure (Pauly et al., 1998; Micheli and Halpern, 2005; Villéger et al., 2010). As a result, the conservation and restoration of marine biodiversity and functions is a major concern (Balmford et al., 2005). Marine protected areas (MPAs) are recommended to promote the recovery of exploited populations and conserve or restore habitats, ecosystems, and biodiversity (Lubchenco et al., 2003). Marine protected areas have also been recommended as tools for ecosystem-based management (EBM) of marine resources (Pauly et al., 2002; Halpern et al., 2010) and for restoration of ecosystem function (Mumby et al., 2007; Mouillot et al., 2008). However, some studies have failed to detect significant differences in ecological response variables between no-take and reference areas, or have criticized the design of existing studies, fuelling the view that the importance of MPAs as a management tool may have been overstated (Hilborn et al., 2004; Murawski et al., 2005; Osenberg et al., 2006).
Some attempts have been made recently to generalize the ecological effects of MPAs (Mosquera et al., 2000; Côté et al., 2001; Halpern, 2003; Micheli et al., 2004; Guidetti and Sala, 2007; Claudet et al., 2008; García-Charton et al., 2008; Harmelin-Vivien et al., 2008; Lester and Halpern, 2008; Lester et al., 2009; Molloy et al., 2009; Claudet et al., 2010). However, ecological effects can vary both in direction and magnitude (Micheli et al., 2004; Claudet et al., 2008; Guidetti et al., 2008; Lester et al., 2009; Molloy et al., 2009; Claudet et al., 2010). This heterogeneity in response to protection may stem from differences in the design or age of MPAs, life histories of focal taxa, the socio-cultural context within which MPAs are established, or a combination of these effects.