The effect of contrasting threat mitigation objectives on spatial conservation priorities

The primary role of marine protected areas (MPAs) is marine conservation, however policy and practice around MPAs have not reflected this. The focus on cost-effectiveness by spatial conservation prioritization has led to a bias towards placing MPAs in areas that are least threatened. This study investigates how conservation priorities differ between two management strategies of either targeting or avoiding high threat areas for protection, using the case of the Sulu Sulawesi Seas in the Coral Triangle. For both strategies, the target of protecting 20% of habitat could not be achieved solely by protecting low threat areas. A high proportion of the region had large differences in conservation outcomes between the two strategies; majority of these areas were highly prioritized in the threat avoidance strategy but had low or zero importance in the threat selection strategy. Selecting for highly threatened areas required less habitat area to be protected to achieve the same conservation target and resulted in a more equitable distribution of priority sites per country and sub-region. This demonstrates the importance of deciding on the objectives of conservation and management policies up-front. The results suggest that, contrary to the common practice of avoiding threats in spatial planning, a threat selection strategy should be part of the management toolbox, particularly in transboundary planning for regions with high overall threat levels, where it may be important to achieve shared conservation targets equitably.