Habitat‐dependent movement rate can determine the efficacy of marine protected areas

Abstract

Theoretical studies of marine protected areas (MPAs) suggest that more mobile species should exhibit reduced local effects (defined as the ratio of the density inside vs. outside of the MPA). However, empirical studies have not supported the expected negative relationship between the local effect and mobility. We propose that differential, habitat-dependent movement (i.e., a higher movement rate in the fishing grounds than in the MPA) might explain the disparity between theoretical expectations and empirical results. We evaluate this hypothesis by building two-patch box and stepping-stone models and show that increasing disparity in the habitat-specific movement rates shifts the relationship between the local effect and mobility from negative (the previous theoretical results) to neutral or positive (the empirical pattern). This shift from negative to positive occurs when differential movement offsets recruitment and mortality differences between the two habitats. Thus, local effects of MPAs might be caused by behavioral responses via differential movement rather than by, or in addition to, reductions in mortality. In addition, the benefits of MPAs, in terms of regional abundance and fishing yields, can be altered by the magnitude of differential movement. Thus, our study points to a need for empirical investigations that disentangle the interactions among mobility, differential movement, and protection.

Reviewing the Ecosystem Services, Societal Goods, and Benefits of Marine Protected Areas

“…This has been also confirmed in fish species that show high individual variability in residence and in the spatial range of their movements (Maggs et al, 2013;Andrzejaczek et al, 2020). Some authors have suggested that this may be due to a modification of the behavior of fish within protected areas, with a higher movement rate in the fishing grounds than in the MPA (Jiao et al, 2018).…”

The dynamics of evolutionary rescue from a novel pathogen threat in a host metapopulation

“…Overall, our model has allowed us to characterize the relative impact of epidemiological, ecological, and evolutionary dynamics in a metapopulation structure to explore how each contributes to shaping the probabilities of pathogen and host persistence. Especially as disease surveillance technologies [67][68][69] , including genetic sequencing, become more easily and affordably available, we believe this eco-evo-epi framework will be critical in generating concrete hypotheses for empirical testing and allow us a much fuller understanding of how disease risks affect the natural world.…”

Modelling spatial variation in an exploited species across marine reserve boundaries

“…Schematic shows how estimating the extent of edge effects (i) and spill-over (ii) differs between approaches due to different representation of spatial gradients (represented by red colour gradient and arrows) across marine reserve boundaries. areas may contribute to discontinuity across reserve boundaries (Alqawasmeh & Lutscher, 2019;Jiao et al, 2018).…”

“…Januchowski‐Hartley et al, 2013), and the impact of different modelling strategies on the interpretation of spatial gradients has not been assessed. However, theoretical modelling studies have tested assumptions regarding continuous movements across reserve boundaries and proposed behavioural aversion to harvesting activity and degraded habitats in fished areas may contribute to discontinuity across reserve boundaries (Alqawasmeh & Lutscher, 2019; Jiao et al, 2018).…”