Autonomous Underwater Vehicle (AUV) for mapping marine biodiversity in coastal and shelf waters: Implications for marine management

Autonomous Underwater Vehicles (AUVs) have only recently become available as a tool to investigate the biological and physical composition of the seabed utilizing a suite of image capture and high-resolution geophysical tools. In this study we trialled the application of an AUV, integrating AUV image capture with ship-based high resolution multibeam bathymetry, to map benthic habitats and biodiversity in coastal and offshore waters of SE Tasmania. The AUV successfully surveyed a plethora of marine habitats and organisms, including high-relief kelp-dominated rocky reefs to deep mid-shelf reef and sediments that are otherwise difficult to access. To determine the spatial extent of these habitats within a broader-scale context, the AUV surveys were integrated with larger scale multibeam mapping surveys. The data collected using the AUV significantly improved our understanding of the distribution of benthic habitats and marine organisms in this region, with direct application to the management and conservation of these environments. For example, preliminary results identified the distributional extent of an introduced invasive marine pest, the screw-shell Maoricolpeus roseus, which was recorded adjacent to rocky reefs but is now known to also extend in high abundance across the SE shelf. Integrating the AUV data with the largescale mapping data provided the opportunity to quantify the relationships between the biological and physical variables, and to use this data to develop predictive models of biodiversity across the region. The effectiveness of the AUV as a pioneering tool for undertaking spatially repeatable surveys makes it a highly versatile technique for future use in surveying remote environments, particularly with respect to surveying and monitoring biodiversity in newly established Commonwealth MPA´s. It also has application in the context of climate change, the study of invasive species, impacts of fishing activities and determining the relative uniqueness - - and/or representativeness of these marine environments.