NESP Biodiversity Hub Hunter Marine Park Multi Beam Echo Sounder Surveys

Gridded multi-beam echousounder (MBES) bathymetry data for Hunter Marine Park acquired using NSW Department of Planning Industry and Environment MBES system aboard RV Bombora for the National Environmental Science Program (NESP Biodiversity Hub). Fieldwork was funded, both cash and in-kind, by NSW DPIE and NESP in Year 1 (2015) and 4 (2018) of the D3 Project. Initial surveys (2015) were exploratory as long-lines across the inner Special Purpose Zone (trawl) over the continental shelf with later surveys (2018) focused on 100% coverage over areas previously identified as containing the Key Ecological Feature ‘Continental Shelf Reef’. Reports by Davies et al (2016) 'Mapping Shelf Rocky Reef Habitats in the Hunter Commonwealth Marine Reserve', National Environmental Science Program Biodiversity Hub D3 Project –Evaluating and monitoring the status of marine biodiversity assets on the continental shelf; and Williams et al (2020) 'Mapping and characterising reef habitat and fish assemblages of the Hunter Marine Park', Project D3- Preparing for and implementing monitoring of CMR’s and the status of marine biodiversity assets on the continental shelf, Milestone Report December 2020; detail these MBES surveys as well as towed underwater video and BRUVs, to characterise seabed habitats, fish and sessile invertebrate assemblages of the Hunter Marine Park. Reports are available at https://www.nespmarine.edu.au/publications. Survey sites for focused mapping in 2018-19 were 1) 3-6 NM east and south-east of Seal Rocks - Sugarloaf Point, 2) Outer Gibber - a feature in 20-60m of water north-east of Broughton Islands and ~3-4 NM from shore and 3) 3-7 NM east to north-east of Broughton Island. MBES data were obtained using either a Geoswath 125 KHZ swath bathymetry system (2015) or a R2Sonic 2022 (2018) with Applanix Wavemaster POSMV with either Single-Base or Precise-Point-Positioning modules in POSView for improved vessel Smoothed Best Estimate of Trajectory. Data were cube modelled in Fledermaus/Qimera software to IHO 1B standard and cleaned-soundings exported before gridding by bin-weighted averaging at 5 m relative to Australian Height Datum and in grid coordinates as UTM WGS84 Zone56. Details on processing are provided at https://www.environment.nsw.gov.au/-/media/OEH/Corporate-Site/Documents/Research/Our-science-and-research/seabed-nsw-standard-operating-procedures-multibeam-surveying-190101.pdf. Data packages including bathymetry and backscatter in multiple formats are provided on the Australian Oceanographic Data Network (https://portal.aodn.net.au); Gridded data in geotif format are also provided on AusSeabed https://portal.ga.gov.au/persona/marine. Data are not to be used for navigation purposes.