Hawaiʻi’s coral reefs support a vibrant array of animals and plants, providing cultural, economic, and recreational opportunities to residents and visitors. However, pollution, overfishing, and ocean warming threaten Hawaiʻi’s coral reefs. In 2016, Hawaiʻi Governor David Ige announced the Hawaiʻi Marine 30-by-30 Initiative, under which the State commits to effectively manage 30% of Hawaiʻi’s reefs by 2030. To target areas for potential management measures, Hawaiʻi natural resource managers need to better understand reef location and condition across its coastline. The Lenfest Ocean Program is funding a project led by Dr. Greg Asner, Director of Arizona State University’s Center for Global Discovery and Conservation Science, to use cutting edge mapping technologies to generate high-resolution maps of nearshore coral reef habitat across the eight main Hawaiʻian Islands.
In less than fifty years, Hawaiʻi’s coral reefs have undergone alarming losses in coral extent and health driven by destructive fishing, pollution, and unsustainable tourism co-occurring against a backdrop of ocean warming. In response, Hawaiʻi developed the Marine 30-by-30 Initiative to reduce local stressors and to enhance resilience of nearshore coral reefs. The Hawaiʻi Division of Aquatic Resources, National Oceanic and Atmospheric Administration (NOAA) and other supporting organizations are now working to identify which of Hawaiʻi’s reef habitats will be selected for management. Then, over the coming years state managers and partners will work with local communities to develop and implement effective management measures. Examples include reducing sediment and nutrient runoff from land, addressing invasive species, and limiting illegal and unsustainable fishing.
To support this effort, Hawaiʻi is requesting region-wide data and information about the extent of living and dead coral reefs. To date, large-scale reef mapping has not been done because of limitations in traditional approaches. For example, dive surveys allow assessment of reef condition, but are too time intensive and expensive to conduct across all eight islands. Satellite-based approaches may provide maps across large spatial scales but miss the details of reef condition.
In this project, Dr. Asner and his team will produce high-resolution maps of coral reefs in waters up to 15 m depth across the eight main Hawaiʻian Islands. The research team will use the Global Airborne Observatory (GAO), which is Dr. Asner’s aircraft-based laboratory that is fitted with an advanced three-instrument remote sensing package known as the Airborne Taxonomic Mapping System (AToMS). Now in its third generation, the GAO uses one of the most advanced mapping technologies in the civil sector today.
While flying over nearshore areas, the cameras and spectrometers measure optical and spectral signatures of both the water column and seafloor, which are then analyzed to:
Dr. Asner and his team have already collected raw data from previous low-altitude flight surveys taken from over 750 miles of Hawaiʻian coastlines. With these data, they will develop and disseminate maps of these ecosystems to help state managers evaluate reef habitats. The maps can also be used by managers to engage local communities over the next several years as the Marine 30-by-30 Initiative transitions from planning to development and implementation of management measures.
The project started in March 2019 and will span one year.
For any questions, please contact Emily Knight, Manager, Lenfest Ocean Program, at eknight@lenfestocean.org. To learn more about this research and stay up to date on our latest projects, follow us on Twitter @lenfestocean or sign up for our newsletter at lenfestocean.org.