How Do Storms Affect Coral Communities? Laura Mudge to Present at Coral Reef Symposium

Laura Mudge swimming over a patch of elkhorn coral in Akumal, Mexico. (Photograph taken by Baruch Figueroa-Zavala)

Coral reefs provide a home to 25 percent of all marine life, yet they are increasingly under threat from climate change. Tropical storms, which are known to damage coral reefs, are predicted to increase in both intensity and frequency due to climate change.

Integral scientist Laura Mudge, Ph.D., will present groundbreaking research in “Quantifying Resilience of Contemporary Caribbean Coral Communities to Multiple, Climate-Driven Disturbances.” Although much research has been conducted in the past on healthy reefs, few scientists understand how storms impact reefs that are already in trouble. During her presentation, Dr. Mudge will define how storms affect corals on reefs that are degraded and discuss the impacts to reefs when other disturbances occur with storms. Dr. Mudge will present on July 21, from 7:00–8:00 p.m. CEST at the International Coral Reef Symposium.

Summary of Research

Authors: L. Mudge, Integral Consulting Inc.; J. Bruno, University of North Carolina at Chapel Hill, United States

Climate change is expected to increase the intensity and/or frequency of tropical storms, which are important drivers of coral reef community structure and functioning. Past work has quantified the effect of storms on living coral cover (mainly on pristine, high cover reefs), yet we know little about how storms affect coral community structure on contemporary, degraded reefs. Furthermore, we do not understand how storms may interact with other types of disturbances. Disturbances interact by altering the likelihood, extent, or severity of a subsequent event, or by altering the recovery time after the next event. These interactions have the potential to create novel or compound effects, which could affect coral community resilience.

We quantified scleractinian coral community resilience to hurricanes, coral bleaching, and disease through a framework that considers multiple, interacting disturbance events and types. Using a regional database of Caribbean coral reef surveys from ~3,000 unique reef locations, we first characterized past disturbance impacts from hurricanes between 1970 and 2017. We found that coral reef communities are becoming more resistant to hurricane damage (i.e., less immediate coral loss), but are not recovering to pre-disturbance states. Our results also suggest that storms are facilitating a shift towards coral assemblages dominated by weedy species. As recovery time becomes limited with more frequent disturbances, understanding reef resistance may give us greater insight into which reefs can persist under predicted changes to disturbance regimes. Additionally, we investigated the interactions between hurricanes, coral bleaching, and coral disease and their cumulative effects on coral assemblages. We found a negative synergistic impact between storms and disease on both the total loss and rate of change in coral cover. Results of this study provide subregional information on disturbance clustering and interactions, which may be used to evaluate the susceptibility of potential reef restoration locations to multiple, climate-driven disturbances.

For more information, contact Dr. Mudge at lmudge@integral-corp.com.