Siting MPAs for multiple protecting purposes by co-consideration of ecological importance and anthropogenic impacts.

The global marine ecosystem has been significantly altered by the combined effects of multiple anthropogenic impacts. Systematic planning of marine protected areas (MPAs) is of paramount importance in alleviating conflicts between humans and the sea. Existing approaches, however, merely integrate both ecological and anthropogenic factors for multiple conservation purposes. By combining the three main anthropogenic impact factors with two main ecological importance factors, this study used a GIS-based AHP-OWA method to identify different levels of priority protection for MPAs in Zhejiang, China. Our results proved that: 1) the multi-objective MPA siting issues can be addressed by the GIS-based AHP-OWA method through scenario simulation; 2) the best locations for MPAs are in the northeast, central, and southern marine areas of Zhejiang; 3) considering the trade-off degree, spatial conservation efficiency, and spatial heterogeneity, an optimized MPA siting scheme can be developed for decision-makers. The proposed MPA siting method and case study may provide an effective technical reference for solving regional marine spatial planning (MSP) issues in the future.