Beagle Marine Park Post Survey Report: Southeast Marine Park Network

This report presents preliminary results and observations of a seabed mapping and biodiversity survey of Beagle Marine Park, within the South-East Marine Park network. The survey was undertaken in 2018 by the Institute for Marine and Antarctic Studies (University of Tasmania), Geoscience Australia and the University of Sydney Centre for Field Robotics as part of Marine Biodiversity Hub Project D3—Implementing monitoring of Australian Marine Parks and the status of marine biodiversity assets on the continental shelf.

The objective of the survey was to collect field data to build baseline information by characterising benthic habitats in shelf waters of Beagle Marine Park that will support ongoing monitoring of the park, and adjacent Bass Strait habitats. Existing bathymetry mapping and underwater imagery for the park indicated that the seabed is characterised by soft sediments with some low-profile reef. The reefs are recognised as a Key Ecological Feature (KEF), but their true extent was unknown and they had yet to be described from a biodiversity and ecological perspective.

The survey was completed over three stages between June and November 2018, comprising: Stage 1 – Seabed mapping to acquire high resolution bathymetry and backscatter data across 13 survey grids, covering a combined area of 407 km2; Stage 2 –Deployment of an Autonomous Underwater Vehicle (AUV) to acquire high resolution downward-facing imagery of epibenthic biota and seabed substrate along 15 transects to characterise reef and adjacent soft sediment habitats, plus targeted dredge sampling of reef material and seabed sediments; Stage 3 – Deployment of Baited Remote Underwater Stereo Videos (stereo BRUVs) at 124 sites to acquire footage of demersal fish assemblages. Importantly, all stages of the survey, from mapping to BRUV deployment, were based on a spatially-balanced sampling design to ensure that estimates of proportion of habitat types or abundances of key species, were representative of the park as a whole.