The influence of marine protected areas on changes in reef fish diversity in the centers of marine diversity and adversity

Maintaining biodiversity in marine ecosystems benefits society by providing sustenance and other ecosystem services. The Philippines is the center of global marine diversity and yet its Central Visayas are the center of marine conservation adversity due to overfishing, habitat degradation, and recent declines in species diversity. To address these impacts, an extensive network of marine protected areas (MPAs) has been delineated to support biomass and biodiversity, and promote sustainable fisheries production in the surrounding areas via the spillover effect. The purpose of this study is to test for an effect of MPAs and human population size on changes in reef fish species diversity in the Central Visayas between surveys conducted in 1978-79 and 2016-22. The historical and contemporary datasets of species abundance were collected with similar methodologies enabling a rare opportunity to make meaningful comparisons between eras. Preliminary species accumulation curves are consistent with a reduction in reef fish species richness between historical and contemporary surveys. We constructed an index of MPA influence using a principal components analysis of factors associated with MPA influence. I will present the results of a mixed-model analysis designed to test for effects of MPA influence and population size on species richness, while controlling for covariates such as depth and habitat type. The results of this study can be used to assess the effect of MPAs on species diversity outside of their boundaries, which can better inform spatial marine management strategies, both in the Central Visayas and beyond.