The Role of Natural Variability in Shaping the Response of Coral Reef Organisms to Climate Change

Purpose of Review We investigate whether regimes of greater daily variability in temperature or pH result in greater tolerance to ocean warming and acidification in key reef-building taxa (corals, coralline algae). Recent Findings Temperature and pH histories will likely influence responses to future warming and acidification. Past exposure of corals to increased temperature variability generally leads to greater thermotolerance. However, the effects of past pH variability are unclear. Variability in pH or temperature will likely modify responses during exposure to stressors, independent of environmental history. In the laboratory, pH variability often limited the effects of ocean acidification, but the effects of temperature variability on responses to warming were equivocal. Summary Environmental variability could alter responses of coral reef organisms to climate change. Determining how both environmental history as well as the direct impacts of environmental variability will interact with the effects of anthropogenic climate change should now be high priority.