Projected Changes in Coral Cover On Reefs

Coral reefs worldwide are threatened by human activity, through overfishing, marine pollution, and disease. In recent years, increasing attention has also been paid to the possible vulnerability of coral reefs to climate change and ocean acidification. In particular, Ocean temperatures of only 1- 2°C warmer than the usual summer maxima can cause the phenomena known as coral bleaching, a breakdown of the symbiosis between the reef-building corals and the colourful symbiotic algae which live in coral tissue.  The breakdown of this symbiosis deprives the coral animal of a critical food source and can lead to mortality.

A range of recent studies have concluded that climate change will rapidly increase the frequency of mass bleaching events, leading to declines in coral cover, shifts in the composition of corals and other reef-dwelling organisms, and stress on the human populations who depend on coral reef ecosystems for food, income and shoreline protection. In this presentation, I will summarize existing research on the role of human-induced climate change in recent mass coral bleaching events, the projections for the future, and the implications for marine conservation and climate policy.  Results will be presented from recent regional and global climate modeling studies and from field work in the central equatorial Pacific.