This project generated a set of high-quality eDNA-based biodiversity datasets from samples collected at broadly distributed offshore sites across Southeast Australia. The data consists of processed data from eDNA metabarcoding assays (i.e. tables with sampling information, sequence read counts and taxonomy derived from the sequences). Raw sequence data (over 180 million sequences) is available from NCBI (https://www.ncbi.nlm.nih.gov/) under BioProject PRJNA1263580: Environmental DNA measuring offshore marine biodiversity in southeast Australia (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA1263580/). The eDNA biodiversity information focussed on fish but includes sequence data from the full tree of life (from bacteria to vertebrates). Part of the purpose of data collection was to assess key technical aspects of eDNA data collection to refine sampling methods and provide guidance for best practices in future offshore eDNA research

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 project "Environmental DNA for measuring offshore marine biodiversity: what can DNA in water collected from the RV Investigator tell us?". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Environmental DNA (eDNA) in seawater provides a non-extractive way to characterise marine biodiversity from genetic material shed by organisms, from microbes and plankton to invertebrates and fishes. It is an emerging tool for marine ecosystem monitoring, particularly in offshore areas where conventional sampling can be difficult, costly or environmentally disruptive. This project collected and analysed more than 500 eDNA samples from 91 sites during the South-east Australian Marine Ecosystem Survey (SEA-MES) on RV Investigator. Samples were collected along the continental shelf between Tasmania and southern New South Wales, including sites within the South-east Marine Parks Network, providing the first comprehensive eDNA baseline for this region. The project tested active eDNA sampling from CTD water samples and passive eDNA sampling from a deep-towed camera system. DNA metabarcoding and Tree of Life metabarcoding were used to identify biodiversity patterns across the water column and near the seafloor. Results were compared with conventional survey methods, including fish trawls, plankton sampling and deep-towed camera deployments, to assess how eDNA complements existing monitoring approaches. The dataset revealed clear biodiversity patterns by depth, latitude, and water-column position, including higher fish diversity near the seafloor than at the surface. Comparisons with trawl and plankton data showed that eDNA provided complementary biodiversity information, supporting its use alongside existing survey methods and highlighting its value as part of integrated monitoring programs. The outputs provide a new biodiversity baseline for south-eastern Australian waters, and practical guidance on future application of eDNA techniques for offshore monitoring of marine parks and fisheries. Outputs • eDNA sequences with associated collection metadata (x2 voyages x50 sites) [dataset] • Final project report [written]

The National Reef Monitoring Network brings together shallow reef surveys conducted around Australia into a centralised database. The IMOS National Reef Monitoring Network sub-Facility collates, cleans, stores and makes this data rapidly available from contributors including: Reef Life Survey, Parks Australia, Department of Biodiversity, Conservation and Attractions (Western Australia), Department of Environment, Water and Natural Resources (South Australia), Department of Primary Industries (New South Wales), Tasmanian Parks and Wildlife Service and Parks Victoria. The data provided by the National Reef Monitoring Network contributes to establishing and supporting national marine baselines, and assisting with the management of Commonwealth and State marine reserves. The Australian Temperate Reef Network (ATRC) aims to improve biodiversity conservation and the sustainable management of marine resources by coordinating surveys of rocky and coral reefs using scientific methods, with the ultimate goal to improve coastal stewardship. Our activities depend on the skills of marine scientists, experienced and motivated recreational SCUBA divers, partnerships with management agencies and university researchers, and active input from the ATRC partners. ATRC data are freely available to the public for non-profit purposes, so not only managers, but also groups such as local dive clubs or schools may use these data to look at changes over time in their own local reefs. By making data freely available and through public outputs, ATRC aims to raise broader community awareness of the status of Australia's marine biodiversity and associated conservation issues. This dataset contains data on the cover of macroalage and sessile invertebrates collected in situ at Australian Temperate Reef Collaboration (ATRC) sites. Quadrats are placed at 10 m spacing along each transect line (i.e. 5 per 50 m transect and 20 per contiguous 200 m) by divers skilled in macroalgal identification. The canopy layer, mid-story and substrate are sequentially assessed in each single, 50 -point quadrat.