New tool aims to help coral reefs survive climate change

Scientists have developed a practical method for assessing the resilience of coral reefs to climate change and for prioritizing local actions to help reefs survive. Jeff Maynard and fellow scientists tested the method in Keppel Bay of the southern Great Barrier Reef Marine Park and found that it can be a useful tool for conservation planning.  

Warmer seawater and other stressors associated with climate change loom as a major threat to coral reefs. Coral reefs have some inherent capacity to endure and recover from environmental stressors, but this resilience varies among reefs and may be affected by localized human impacts such as anchor damage.  

Although mitigating climate change itself is one way to help coral reefs, many people want to take complementary action at the local level. A large number of studies have identified factors that may influence reef resilience. Maynard and his collaborators sought to integrate this scientific information into a useful format for on-the-ground conservation.  

By combining 19 indicators believed to reflect resilience of coral reef ecosystems, the new method generates an overall resilience score for each reef site. Among the most important indicators are coral cover, abundance of resistant/tolerant species, and previous exposure to thermal stress.

Only four indicators can be influenced directly by management: fishing pressure, water pollution, sedimentation, and anthropogenic physical impacts.  

Scores for each indicator are generated based on expert knowledge or existing data. High scores indicate reefs with the most capacity to persist in a changing climate, and the four management-specific indicators can be used to identify local actions that may enhance resilience.

Maynard and his collaborators tested the method in Keppel Bay, where resource managers, scientists, recreational fishermen, local officials, and other stakeholders scored the indicators for 31 reef sites. Maynard’s team calculated the composite resilience score for each site, and they analyzed the types of management actions that would be most beneficial for boosting reef resilience at each site.

The researchers published their findings in the journal Coral Reefs. Based on the new information, decision-makers decided to establish four no-anchoring zones in specific parts of Keppel Bay as an immediate first step toward enhancing reef resilience. According to the study authors,

“The assessment framework represents a step toward making the concept of resilience operational to reef managers and conservationists. Also, it is customizable, easy to teach and implement and effective in building support among local communities and stakeholders for management responses to climate change.”

--Reviewed by Pete Taylor

Note: The study referenced in this article is still in press but will be available the week of March 29, 2009.

Maynard, J., Marshall, P., Johnson, J., & Harman, S. (2010). Building resilience into practical conservation: identifying local management responses to global climate change in the southern Great Barrier Reef Coral Reefs DOI: 10.1007/s00338-010-0603-8