The last hotspots of structural complexity as conservation targets in the Mesoamerican Coral Reef

Abstract

Coral reefs are highly diverse marine ecosystems offering invaluable services to hundreds of million people worldwide. These ecosystems are currently threatened by global and local stressors, particularly affecting structurally complex coral species in depauperate zones such as the Caribbean. Marine protected areas (MPAs) can counteract climatic and local human stressors and offer a source of ecosystem resilience in the Anthropocene. Yet, their protective effect on structurally complex corals is still under scrutiny, while this could give light to management strategies towards the protection of such remaining “hotspots”. This study examined the combined effects of local stressors (human gravity) and thermal stress (maximum Degree Heating Week) on scleractinian corals' community structure over 158 sites located in the Mesoamerican Reef and evaluated how MPAs can mitigate these stressors. Our results suggest that MPAs can buffer the impacts of local human stressors on coral reefs, yet there is a spatial mismatch between hotspots of structural complexity and the level of protection since 41% of these sites were not protected in 2016. We recommend these last hotspots of structural complexity as priority areas for increased protection coverage and enforcement in the Mesoamerican Reef.