Benthic Spectrometry Methods

Field methods have been developed to assess ecosystem health and for validation and calibration purposes. We focus on close range, and spectrometry.

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 2024-2027, The Lott 2023-2026,  past funding: Coastal CRC, Office of Navel Research, ARC Linkage 

Summary

Features on the earth’s surface reflect light differently, as a result, they are unique. With Spectrometry, we measure the spectral characteristics of features at different wavelengths at a high level of detail, forming a spectral signature of an end member. For submerged features, we focus on 300-800 nm wavelength, as at higher wavelengths (700 nm onwards) the light is absorbed and does not penetrate anymore.

Spectral signature analysis forms the basis of assessing the ability if, under ideal situations, benthic features could be separated from each other, such as live coral from algae or different seagrass species from each other.  

Spectral signatures for underwater features are measured by bringing the subject to the surface and measuring in a lab which provides a safe environment but risks the subject being disturbed, or by measuring a feature in its natural environment with a spectrometer that is built in an underwater housing by a scuba diver.

Through our research, we have built various setups with collaborators and collected spectral libraries of coral reef and seagrass habitat features, several of these libraries are publicly accessible.  These libraries have been studied and analysed in detail to assess the capability of remote sensing to differentiate features at various depths, water properties and compositions. 

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Publications

Scientific journals

  • 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  

  • B.A. Rasaiaha, C.Bellman, L. Chisholm, J. Gamon, A. Hueni, A. Huete, S.D. Jones, C. MacLellan, T.J. Malthus, C. Ong, S. Phinn, C. Roelfsema, L.Suarez-Barranco, P. Townsend, R.Trevithick,  M Wyatt  (2013) Approaches To Establishing A Metadata Standard For Field Spectroscopy Datasets. In Proceedings IGARSS 2013July, Melbourne, Australia  

  • Hedley J. D., S.R. Phinn, C.M. Roelfsema and B.Koetz  (2012) Capability Of The Sentinel 2 Mission For Tropical Coral Reef Mapping And Coral Bleaching Detection. Sentinel Special Issue of Remote Sensing of Environment. https://doi.org/10.1016/j.rse.2011.06.028   

  • Hedley, J.D., C.M., Roelfsema, S.R. Phin and P Mumby (2012) Environmental and Sensor Limitations in Optical Remote Sensing of Coral Reefs: Implications for monitoring and sensor design. Remote Sensing., https://doi.org/10.3390/rs4010271 

  • 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.  

  • Hedley, J.D., C.M., Roelfsema and S.R. Phinn (2009) Efficient radiative transfer model inversion for remote sensing applications. Remote Sensing of Environment. https://doi.org/10.1016/j.rse.2009.07.008 

  • 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: Benthic Spectral Reflectance Data sets

  • Roelfsema, Christiaan M; Phinn, Stuart R (2017): Spectral reflectance library of healthy and bleached corals in the Keppel Islands, Great Barrier Reef. PANGAEA, 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. PANGAEA, https://doi.org/10.1594/PANGAEA.872506

  • Roelfsema, Christiaan M; Phinn, Stuart R (2017): Spectral reflectance library of corals and benthic features in the Cook Islands (Aitutaki). PANGAEA, https://doi.org/10.1594/PANGAEA.872505

  • Roelfsema, Christiaan M; Phinn, Stuart R (2013): Spectral reflectance library of selected biotic and abiotic coral reef features in Glovers Reef, Belize. Biophysical Remote Sensing Group, Centre for Spatial Environmental Research, University of Queensland, Australia, PANGAEA, https://doi.org/10.1594/PANGAEA.824861

  • Roelfsema, Christiaan M; Phinn, Stuart R; Joyce, Karen (2016): Spectral reflectance library of algal, seagrass and substrate types in Moreton Bay, Australia. https://doi.org/10.1594/PANGAEA.864310

  • Roelfsema, Chris M; Phinn, Stuart R (2013): Spectral reflectance library of selected biotic and abiotic coral reef features in Glovers Reef, Belize. Biophysical Remote Sensing Group, Centre for Spatial Environmental Research, University of Queensland, Australia, Dataset https://doi.org/10.1594/PANGAEA.824861

  • Roelfsema, Christiaan M; Phinn, Stuart R (2012): Spectral reflectance library of selected biotic and abiotic coral reef features in Heron Reef. Centre for Remote Sensing & Spatial Information Science, School of Geography, Planning & Environmental Management, University of Queensland, Brisbane, Australia, PANGAEA, https://doi.org/10.1594/PANGAEA.804589

  • Roelfsema, CM; Phinn, SR (2012): Spectral reflectance library of selected biotic and abiotic coral reef features In Heron Reef, https://doi.org/10.1594/PANGAEA.804589