Why 100 Island Challenge?

Coral reefs cover less than 0.1% of the Earth’s surface, yet are estimated to support greater than 25% of marine biodiversity. For the hundreds of millions of people living adjacent to coral reefs, this productive ecosystem provides important shoreline protection and critical food security. Alarmingly, a combination of local human influences and global climatic changes are altering the structure and functioning of many reef ecosystems.

For years, our team at Scripps Institution of Oceanography has been working to establish a regional scale perspective of coral reef health, investigating how reefs are structured, how they change over time, and how we can better manage them in the face of global change. To accelerate this crucial effort, we propose a campaign of field surveys across the tropical Pacific and beyond that will generate critical data about reef ecosystems through time.

By using a collection of survey technologies coupled with ecological theory and quantitative models, we will gain important insights into the relative condition of coral reefs from across locations, using large-scale geographic scope to provide context for comparisons across locations. By developing a rigorous and repeatable sampling protocol, especially with the inclusion and sharing of high-resolution data (fish, benthic, oceanographic) and novel reef visualization products (i.e. large-area ‘photomosaics’) in collaboration with engineers, we can inform and educate managers and other stakeholders about how their coral reefs work and what is needed to ensure that reefs persist into the future.

Research Questions

As a consequence of global coral reef decline, new techniques to slow, halt or reverse patterns of degradation have become both a research objective and a management priority. Comprehensive documentation on the causes of coral reef decline indicates that natural and anthropogenic stressors, such as major storms, pollution, and overfishing, interact with global change stressors such as warming and ocean acidification to cause reef loss. Yet we lack clear information regarding the specific pathways involved in these declines.

A number of important questions emerge that require novel approaches to answer.

  • How do global stressors (warming, ocean acidification, El Niño) affect coral reefs that experience different natural and anthropogenic conditions? Are remote reefs without human populations better at combating global stressors than reefs adjacent to human settlements?
  • Can local management activities (e.g., of fisheries, water quality, watersheds) enhance the ability of a reef to withstand global stress events? Or if not, can these activities increase resilience by facilitating recovery?
  • Can active intervention (cultivation of resistant or weedy coral species and transplantation, restoration of herbivore populations, etc.) help to mitigate global impacts on coral reefs?

 Without clear insights into the mechanisms of change within a coral reef community, it is impossible to resolve debates regarding the most effective means to manage a reef for increased community health.


The 100 Island Challenge team based at Scripps Institution of Oceanography, led by Drs. Stuart Sandin and Jennifer Smith.