Ningaloo reef: shallow marine habitats mapped using a hyperspectral sensor

PLoS One. 2013 Jul 26;8(7):e70105. doi: 10.1371/journal.pone.0070105. Print 2013.

Abstract

Research, monitoring and management of large marine protected areas require detailed and up-to-date habitat maps. Ningaloo Marine Park (including the Muiron Islands) in north-western Australia (stretching across three degrees of latitude) was mapped to 20 m depth using HyMap airborne hyperspectral imagery (125 bands) at 3.5 m resolution across the 762 km(2) of reef environment between the shoreline and reef slope. The imagery was corrected for atmospheric, air-water interface and water column influences to retrieve bottom reflectance and bathymetry using the physics-based Modular Inversion and Processing System. Using field-validated, image-derived spectra from a representative range of cover types, the classification combined a semi-automated, pixel-based approach with fuzzy logic and derivative techniques. Five thematic classification levels for benthic cover (with probability maps) were generated with varying degrees of detail, ranging from a basic one with three classes (biotic, abiotic and mixed) to the most detailed with 46 classes. The latter consisted of all abiotic and biotic seabed components and hard coral growth forms in dominant or mixed states. The overall accuracy of mapping for the most detailed maps was 70% for the highest classification level. Macro-algal communities formed most of the benthic cover, while hard and soft corals represented only about 7% of the mapped area (58.6 km(2)). Dense tabulate coral was the largest coral mosaic type (37% of all corals) and the rest of the corals were a mix of tabulate, digitate, massive and soft corals. Our results show that for this shallow, fringing reef environment situated in the arid tropics, hyperspectral remote sensing techniques can offer an efficient and cost-effective approach to mapping and monitoring reef habitats over large, remote and inaccessible areas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthozoa / growth & development
  • Coral Reefs*
  • Ecosystem
  • Environmental Monitoring / instrumentation*
  • Image Processing, Computer-Assisted
  • Maps as Topic
  • Western Australia

Grants and funding

This project was funded through the CSIRO Wealth from Oceans Flagship Collaboration Fund (http://www.csiro.au/en/Organisation-Structure/Flagships/Wealth-from-Oceans-Flagship.aspx) and Murdoch University (www.murdoch.edu.au). The authors would also like to acknowledge the support of BHP Billiton Petroleum (funding of Hymap survey). The authors would like to declare that the commercial source (BHP Billiton Petroleum) who, through an agreement with the Australian Institute of Marine Science, funded the flights for this project had no involvement in any of the data analysis, nor did this work result or involve any employment, consultancy, patents, products in development or such. The authors can declare that this does not alter their adherence to all the PLOS ONE policies on sharing data and materials.