SURVEY METHODS

WA Museum Records and Supplements | Updated 9 years ago

Introduction: Initial characterisation of habitat types and selection of sampling stations was done using colour aerial photography (DOLA; 850096; runs 1-3; 1:25000; 5/8/85) and Landsat imagery (DOLA; merged SPOT 12/01/92 and TM 27/12/91). Twelve colour prints of the Landsat image, covering the area at a scale of 1:25000 were produced. The aerial photography proved to be more useful, as ground truthing showed the satellite imagery to be unreliable for distinguishing habitat types. Manipulation of wave bands to try to eliminate spurious habitat signatures caused by water depth was not successful. The satellite image, captured in digital form was, however, used interactively to produce amended habitat distributions. The final colour habitat map was generated using a combination of MICROSTATION and CADSCRIPT software. Ground truthing of habitats was undertaken by spot dives from the vessel 'Nor Don' and an inflatable dinghy, and by manta tows.