Coral reef sustainability through adaptation: glimmer of hope or persistent mirage?

Abstract

Coral reefs are highly threatened by human activities at both global (ocean warming and acidification) and local scales (overfishing, pollution, and physical destruction) especially given that current rates of environmental change exceed those seen for tens of millions of years. Recent authors, however, have suggested that coral reefs might increase their tolerance to these rapid environmental changes through acclimatisation, genetic adaptation, and migration. While there is evidence of all three responses acting within coral populations, there is little basis for the conclusion that reef-building corals and coral reefs will become more sustainable and resilient over time under current high rates of change. Most studies that make this claim have correctly identified components and mechanisms but have otherwise incorrectly extended this evidence which is otherwise necessary but not sufficient to support the conclusion that coral reefs will survive due to their ability to acclimatise, adapt and/or migrate to the current rapid environmental changes.