Geomorphology, habitats and surficial sediments of the Ningaloo Reef continental shelf and reef system: implications for biodiversity

The establishment and extension of Sanctuary Zones (SZ) in the Ningaloo Marine Park (NMP) has necessitated improvements in the understanding of the biodiversity and distribution of benthic habitats in the reef lagoon, its seaward barrier and the adjacent shelf environment. My PhD research, supportedby the Ningaloo Research Program (NRP), aims to characterise the geomorphology and surficial sediments in bith the reef system and continental shelf, and identify and evaluate their influence on the spatial distribution of benthic habitats and communities. A major collaborative project, co-funded through NRP and supported by expertise from the Australian Institute of Marine Science (AIMS), Curtin University of Technology, the University of WA, the WA Museum and Sydney University, aims to characterise the biodiversity and key ecological processes of the deepwater habitats, offshore of the fringin reef to 110m. Over 100 kilometers of the northern secto of the Marine Park has been examined using a variety of sampling techniques including underwater video, acoustic mapping and traditional sampling techniques. Towed underwater video cameras and onboard live classifications were used to chartacterise habitats and their community structures. Australia's most advanced Autonomous Underwater Vehicle (AUV), which takes high resolution 3D stereo images of the seafloor, was trialed for the first time. Surficial sediment grabs were taken at or close to video stations to describe the various sediment facies and characterise the physical and biological properties. Species samples, including spectacular sponge gardens, were collected using benthic sleds in representative habitats to form the basis of a deepwater seabed biodiversity database. Baited Remote Underwater Vehicle System (BRUVS), deployed in target habitats, will help determine the significance of spatial habtat variables in structuring demersal fish demograophics and assemblages. Detailed seabed mapping was undertaken in selected areas usinf multibeam and sinlebeam acoustics to generate information on bith the seabed bathymetry and texture, aiding in the preparation of marine habitat maps of the areas surveyed, and provide surrogate information for additional broadscale biodiversity assessments. In addition, work is currently underway to investigate four areas in the backreef area adjacent to those surveyed offshore. Similar methods and sampling applied to shallow water have been used, including aerial photography and hyperspectral satellite interpretation, sediment grabs and probes, scuba video-transects within the deep water within habitats for both benthos and fish characterisation, and BRUVS. This research, in addition to the deep water, will help to build a picture of how each process contributes to the whole system and the sustained health of the reef environment.