AimIncreasingly, marine protected areas (MPAs) are designed for the purpose of maintaining ecological resilience. In this study, we use the case of the Sulu Sulawesi Marine Ecoregion to investigate how conservation priorities differ (i) between single threats and integrated threats; and (ii) for two different management strategies, targeting or avoiding high threat areas for protection.
MethodsThe software MARXAN was used with a target to include 20% of each habitat while minimizing the opportunity costs as represented by foregone artisanal fish catch and foregone access to the mangroves using the global human footprint as a proxy. Three types of threats were considered: coastal development, marine pollution and watershed pollution. MARXAN was implemented for seven scenarios and cluster analysis was conducted on the selection frequencies in R.
ResultsMangroves and shallow coral reefs were the least protected by current reserves. The single threat-averse scenarios for coastal development and marine pollution produced the most similar solutions, followed by the integrated threat-averse scenario and the single threat-averse scenarios for watershed pollution. The priority areas for the single threat-tolerant scenario for watershed pollution and integrated threat-tolerant scenarios were the two most costly.
ConservationConservation priorities show the biggest change under consideration of watershed pollution. Mangroves are the least protected habitat but also the most resistant to watershed pollution and may act as a buffer to adjacent habitats. They should be incorporated into MPAs regardless of watershed pollution levels. However the threat-tolerant strategy may be more costly. Nonetheless watershed management should be a priority for the Sulu-Sulawesi Marine Ecoregion.