Designing fisheries restricted areas using standard fishery survey data: a novel multilevel spatio-temporal approach

Fishery restricted areas (FRAs) are pivotal for the mitigation of fishery impacts, but the designation of optimum FRAs is complex, and currently there is no quantitative guideline to assess the spatio-temporal variability of conservation priority areas. Fishery systems are naturally dynamic, and shifts may at two different levels, the species level and the community level. As a consequence, the identification of optimum FRAs using standard fishery data should follow a spatiotemporal procedure that accounts for both levels of dynamism. Here, we describe an approach to optmise the location of FRAs assessing the spatiotemporal dynamism of conservation priority areas at both the species and the multi-species level. To do so, we first assess species-specific dynamisms through Species Distribution Models (SDMs). Then, we use SDM results to explore different spatial prioritisation software configurations to assess the suitability of fixed, progressive, or more complex fishery restricted area designs. Finally, we assess the ecologic and socioeconomic impact of FRA candidates based on our SDM estimates and fishery footprint data, respectively. The proposed method is illustrated through a western Mediterranean case study using scientific trawl survey data on six commercially important species collected over 17 years. Following this approach, we identified two main priority area patterns in the study area. Each pattern is predominant during a different period of the study, constituting a clear example of the importance of regularly re-assessing FRA designs. We conclude that a spatiotemporal assessment of conservation priority areas using long-term data is essential to inform the location of new FRAs.