Extinction risk of reef corals, past and present

Abstract

Coral reefs are under increasing pressure from direct human impacts and human-induced climate change. Reef corals are also thought to be at elevated extinction risk but estimates vary profoundly among studies. Works that use lost reef area as a proxy of coral population reduction tend to estimate high extinction risk, whereas approaches using estimates of coral population sizes advocate low extinction risk. The fossil record contributes to this discussion that (i) reef corals have low intrinsic extinction risk, (ii) the loss of reef area is a poor predictor of coral extinction rates, and (iii) reef coral extinction pulses were usually triggered by episodes of profound global warming. Taken together, the deep-time observations support that the current reef crisis is unlikely be develop into a coral mass extinction in the next century of so. In addition, the Red List categorization of reef coral conservation status does not align well with empirical extinctions of the near-time past.