Australia’s coasts need monitoring and assessment. Combining drone to spaceborne remote sensing images with a curated aquatic spectral library (including detailed metadata) will enable systematic mapping and monitoring of optically shallow water seabed ecosystems, benefitting marine scientists through to policymakers. The release of this spectral library resource aligns with other significant developments in the Australian aquatic EO community, including the Australian AquaWatch program – a dedicated inland and coastal water in-situ, modelling and Earth observation system- jointly led by the SmartSat CRC and CSIRO.
The Australian Shallow Water Ecosystem Substratum Spectral Library is a feature of the recently released Australian National Spectral Database (NSD) service: https://cmi.ga.gov.au/data-products/dea/643/australian-national-spectral-database one of the analysis ready data initiatives being developed at Geoscience Australia in the Digital Earth Australia (DEA) program.
We accessed spectral libraries from government and academic institutes to capture inter- to sub-tidal seabed features from estuaries to coral reefs. We attributed the spectral data with appropriate meta-data in a community-accessible form. The library contains ~3600 spectra, covering coral, macro- and micro-algae, seagrasses, and related substrata in temperate to tropical inlets, estuaries and reefs ranging from the Great Barrier and Ningaloo Reefs, Coral Sea and the Adelaide, Melbourne, Perth, and Brisbane Coastal Waters.
We provide harmonisation of measurement protocols, and a spectral library metadata template. This can be used to validate and parameterise models including intra-species, interspecies, and substratum type variability. We consider this spectral library metadata to be one of the most complete metadata descriptions available and can significantly improve further spectral measurements as new users/developers/scientists realise what is required to optimise their data under the FAIR principles of findability, accessibility, interoperability, and reusability, although we are working on further improvements
This spectral library supports collating, sharing, discovering and re-using existing spectra, facilitates the capture of new datasets, and improves our benthic mapping and monitoring capabilities. A recently established working group sponsored by the International Ocean Colour Coordinating Group (IOCCG) on Benthic Reflectance intends to produce a comprehensive report about the theory and measurement techniques for estimating benthic reflectance. This Australian Shallow water ecosystem spectral library and related work will contribute to the success of this international working group that has several Australian co-authors involved.