The effects of marine protected area designation and associated restrictions on fisheries in EU MPAs

Abstract Marine protected areas (MPAs) are central to European Union (EU) marine policy, yet their effectiveness remains contested, especially with regard to ongoing fishing activities. Using officially reported fisheries effort data from vessel monitoring systems and logbooks, we analysed 781 MPAs across four ICES ecoregions to quantify fishing activity and assess responses to MPA designation and the imposition of fisheries restrictions. We aggregated effort by gear type, i.e. mobile bottom-contacting gears (MBCG) and passive or pelagic gears (PPG). We applied post-hoc before-after-control-impact (BACI) analyses using generalized linear mixed models. A total of 60% of MPAs were fished after designation, including 44% with MBCG and 55% with PPG, with regional variation from 40% in the Celtic Seas to 89% in the Bay of Biscay and Iberian Coast. MPA designation alone did not significantly change fishing effort for any gear category. The imposition of fisheries restrictions reduced effort across all gears, with declines of 30% in MPAs compared to 13% in adjacent controls. Similar reductions were observed for MBCG (31% vs 15%) and PPG (26% vs 9%). MPAs with benthic conservation objectives experienced reductions in MBCG effort (25% vs 9%), but no significant changes in PPG nor total effort. These findings indicate that designation without accompanying restrictions does not alter fishing behaviour. Contrastingly, fishing restrictions can reduce effort in MPAs, albeit with strong site-level variability, and depending on the type of restrictions that are put in place. Our results highlight the need to set clear conservation objectives when designating MPAs and to develop follow-on management measures tailored to these objectives. By leveraging official effort data and BACI designs at a regional scale, this study provides robust evidence to inform policy discussions on the effects of MPAs as fisheries management tools in EU waters.