Live coral cover and seagrass species composition are key indicators for scientists and managers to assess the health of coral reef habitats. The ability to differentiate between live and dead coral, seagrass species and other bottom features is driven by the density of cover and the spectral characteristics of the features. Research into the ability to detect live coral cover and differentiate seagrass species based on spectral reflectance properties has demonstrated that hyperspectral information (opposed to multispectral) is required.

Currently there have not been any successful attempts to map seagrass species composition across very large spatial extents (e.g. regional to global) nor live coral, with only a handful of examples at local scales (single reefs/meadows to small groups). As part of the Allen Coral Atlas, the UQ team mapped coral habitat globally but were not able to differentiate seagrass species and density, nor live coral cover. This mapping was constrained by the availability of only multispectral sensors (e.g. Sentinel 2, Landsat, Planet Dove) that cover large spatial extent and provide feasible complete global coverage of the world’s coral reef habitats.

The increasing numbers of hyperspectral satellites being launched since 2021, including public good and private-industry systems, capable of global coverage provides the opportunity to investigate these challenges and there is now a need to develop remote sensing frameworks to assess their capability for live coral and seagrass cover mapping. This work aims to acquire very high quality archived hyperspectral data for reef and seagrass environments, in conjunction with field data to test the coral and seagrass properties that can be differentiated from different spatial-spectral-radiometric dimensions to inform processing from future hyperspectral satellites, especially Australia’s Kanyini and the proposed AquaSat systems. Findings from this study may also provide the roadmap for a follow-up phase, to map live coral on shallow coral reefs and seagrass in Australia and globally, providing essential information to coral reef scientist and managers.