A newly released study by the University of Exeter is the first to suggest corals may actually be able to rebound from the negative effects of climate change. The study focuses specifically on the 2% of the world's coral reefs that fall inside of marine protected areas or marine reserves.

Coral reefs are vulnerable to a variety of environmental factors and human activities. Increased water temperature, whether caused by seasonal weather patterns or the more long-term effects of global warming, can cause mass bleaching events where coral polyps are effectively killed off. These bleaching events can be compounded by other negative affects, like the increased acidification of the ocean, overfishing, or dredging by commercial fishing vessels. 

Surveys of ten sites both inside and outside of marine reserve areas outside of the Bahamas over the course of two and a half years. The reefs included in the study were ones that had been previously negatively affected by weather patterns, including Hurricane Frances during the summer of 2004. At the beginning of the study, all of the reefs observed, both protected and unprotected, were shown to have an average of 7% coral cover. At the end of the two and a half year observation period, the coral reefs located inside marine reserve areas had rebounded to almost 20% coral cover; the reefs located in unprotected areas had not had any noticeable gains in coral cover.

While it is possible for a variety of different factors to be at play in the degradation and rebuilding of coral reefs, there is one factor that researchers found to be both easy to control and very influential in protecting coral reefs from other factors like increased CO2. Local action to reduce fishing on coral reefs has been found to have a very positive impact on a reef's ability to rebound from other environmental disturbances. By creating a marine reserve around coral reefs and controlling the amount of fishing that can occur, a larger number of parrotfish are able to flourish. Parrotfish eat seaweed, which allows coral to grow uninhibited and without competition for light. The high number of parrotfish inside the Bahamas' protected reef are strongly correlated with their successful recolonization rates. Those individuals involved with the study hope that their findings will encourage governments to reduce the fishing of key herbivores like parrotfish in order to help reefs cope with the more inevitable effects of climate change.