Imagery of opportunity: benthic habitat maps in deeper shelf waters (30-200 m)

Benthic habitat data remain largely uncollected from deeper continental shelf waters due to prohibitive costs and limits of SCUBA. This study used images from horizontally facing cameras to map tropical, subtropical, and temperate benthic habitats in deeper continental shelf waters (>30 m) of western Australia. We used images typically employed to monitor demersal fish assemblages to derive in situ benthic habitat data cost-effectively. Models of benthic habitat classes explained between ∼10% and 62% of the variance. Benthic habitat extents from dominant and individual classes were mapped. These mapping methodologies derived different habitat cover extents. We recommend using individual benthic habitat classes to model habitat distributions along with their associated error. We developed a novel metric, the Individual Scaled Extent, calculated by scaling individual habitat class predictions relative to the mapped area, to better represent rarer and less dominant habitat classes. We mapped benthic habitats using images from spatially balanced demersal fish surveys across the continental shelf, providing fundamental baseline information on these poorly known ecosystems.