Evaluation of MPA effects on small-scale fisheries: A long-term landings-based monitoring approach

Small-scale commercial fisheries represent a significant economic activity that can be affected by coastal Marine Protected Areas (MPAs). Official fishery landings data can serve as an effective means of evaluating the effects of MPAs on fisheries and harvested species, as they are available over long periods and do not incur any costs. However, the use of long-term landings as a solid baseline for pre-MPA conditions has been rare. In this study, we applied a Before-After-Control-Impact (BACI) design to long-term landings time series to assess the economic and ecological effects of a coastal multi-zone MPA in Portugal. We compared the landings and income per unit of effort (LPUE and IPUE) inside and outside the MPA after its implementation, and within the MPA before and after the implementation. Our results showed that the MPA had a positive influence on the LPUE and IPUE of the local fleet (54 landed taxa in the assemblage), based on significant positive trends inside the MPA after implementation, but not before or outside. We found significant positive responses to protection in four taxa with the highest LPUE: Octopus vulgaris , Conger conger , Soleidae, and Rajidae. The MPA’s small no-take zones likely enhance species with small home ranges and their spillover, and, together with the controlled number of fishing licenses, contribute to positive MPA outcomes. However, the LPUE of Muraena helena and Diplodus vulgaris declined significantly inside the MPA between before and after MPA implementation, which could be attributed to enhanced inter-species competition. Despite encouraging LPUE trends within the MPA, the study revealed that prices evolved in a more favourable manner outside than inside the MPA, suggesting that future research in this topic may be necessary to ensure the proper valuation of fishing resources within this and other MPAs. Despite the common limitations of landings data, our study demonstrates that comparing long-term landings from pre- and post-MPA periods using a BACI design can be an efficient monitoring solution for budget and data-limited coastal MPAs. • Long-term landings analysed in Before-After-Control-Impact design, a rare approach. • Landings after the Marine Protected Area differed from before and outside of it. • Artisanal fisheries demonstrated an increasing trend in income due to protection. • The harvested taxa increased due to no-take zones and limited fishing licenses. • However, prices evolved in a more favourable way outside the Marine Protected Area.