Hyperspectral Seagrass and Coral Mapping

This project assesses and develops approaches using hyperspectral spectrometry and imagery to differentiate live coral from other bottom types and to differentiate seagrass species from one another

Locations
Heron Reef, Eastern Banks (Moreton Bay), Ningaloo Reef, Adelaide coastal waters

People
Dylan Cowley, Chris Roelfsema (PI), Joanna Smart, Kirsten Golding, Nicholas Hammerman, David Enrique Carrasco Rivera

Collaborators
CSIRO, University of Adelaide, South Australian Water Corporation, South Australian Department of Environment and Water

Timeframe
2024 - 2027

Funding
Smart Sat CRC

Summary

Live coral and seagrass species composition are key indicators for scientists and managers to assess the health of coral reef and seagrass 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.

This project aims to develop mapping frameworks that utilise Earth observation data, field measurements, and key spatial, temporal, spectral, and radiometric properties of live coral and seagrass species to enable effective management of these shallow marine environments over large spatial scales (e.g., regional to global).

The primary aim is to assess the capabilities of existing and planned hyperspectral satellites as tools to enable mapping of live coral and seagrass species over these scales.

This involves the acquisition of very high quality archived hyperspectral data for reef and seagrass environments, in conjunction with field data to test the coral, macroalgae, seagrass, and related benthic features that can be differentiated from state-of-the-art hyperspectral satellite imagery from missions such as EnMAP, PRISMA, EMIT, and Kanyini. This project will also initiate the development of machine learning and AI based models and object-based image processing workflows to provide essential tools to both experts and non-experts working towards the effective management of coral and seagrass environments.

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Publications

Scientific journals

  • Bright,C., D Ardila, E Hestir, TJ Malthus, M Matthews, DR Thompson, N Carter, AG Dekker, RPM Frasson, RO Green, A Held, K Joehnk, J Kravitz, J Pease, C Roelfsema, C Seubert, B Wojtasiewicz (2023) The Aquasat-1 Mission Concept: Actionable Information On Water Quality And Aquatic Ecosystems For Australia And Western USA, GARSS 2023-2023 IEEE International Geoscience and Remote Sensing Symposium 

  • Tiit Kutser, John Hedley, Claudia Giardino, C.M. Roelfsema, Vittorio E. Brando (2020) ”Remote sensing of shallow waters – a 50 year retrospective and future directions “, Remote Sensing of Environment; https://doi.org/10.1016/j.rse.2019.111619  

  • Leiper I., S.R. Phinn, C.M. Roelfsema, K.E. Joyce and A.D. Dekker (2014), Mapping Coral Reef Benthos, Substrates, and Bathymetry, Using Compact Airborne Spectrographic Imager (CASI) Data data and Spectral Angle Mapper. Remote Sensing. https://doi.org/10.3390/rs6076423 

  • Borrego-Acevedo, R., C. M. Roelfsema, S. R. Phinn and A. R. Grinham (2014). "Predicting Distribution of Microphytobenthos Abundance on a Reef Platform by Combining in Situ Underwater Spectrometry and Pigment Analysis." Remote Sensing Letters, https://doi.org/10.1080/2150704X.2014.922723  

  • Joyce, K.E., S.R. Phinn, and C.M. Roelfsema (2013) Live Coral Cover Index Testing and Application with Hyperspectral Airborne Image Data. Remote Sensing https://doi.org/10.3390/rs5116116  

  • Dekker A.G., S.R. Phinn, Anstee J., Bissett P., Brando V.E.,  Casey B., Fearns P., Hedley J.,  Klonowski, W., Lee Z.P., Lynch M., Lyons M., Mobley C. , and  Roelfsema C.M. (2011) Intercomparison of shallow water bathymetry, hydro-optics, and benthos mapping techniques in Australian and Caribbean coastal environments.. Limnol. Oceanogr.: Methods https://doi.org/10:4319/lom.2011.9.396  

  • Dekker, A.G., Brando V.E., Anstee, J. M., Botha, E.J., Park, Y.J., Daniel, P., Malthus, T.J.M., Phinn, S.R., Roelfsema, C.M., Leiper, I., Fyfe, S., (2010). A comparison of spectral measurement methods for substratum and benthic features in seagrass and coral reef environments: in Proceedings Art, Science and Applications of Reflectance Spectroscopy Symposium, Boulder Colorado, February 23-25th 2010. ASD Inc. Boulder Colorado, USA. 

  • Brando, V.E., J.M. Anstee, M. Wettle, A.G. Dekker, S.R. Phinn and C.M. Roelfsema (2009).  Physics Based Procedure for Retrieving and Assessing the Quality of Bathymetry from Suboptimal Hyperspectral Data. Remote Sensing of Environment https://doi.org/10.1016/j.rse.2008.12.003 

Scientific Data

  • Roelfsema, Christiaan M; Phinn, Stuart R (2017): Spectral reflectance library of healthy and bleached corals in the Keppel Islands, Great Barrier Reef. https://doi.org/10.1594/PANGAEA.872507   

  • Roelfsema, Christiaan M; Phinn, Stuart R (2017): Spectral reflectance library of healthy corals, bleached corals and other benthic features in Fiji. https://doi.org/10.1594/PANGAEA.872506    

  • Roelfsema, Christiaan M; Phinn, Stuart R (2013): Spectral reflectance library of selected biotic and abiotic coral reef features in Glovers Reef, Belize. https://doi.org/10.1594/PANGAEA.824861