This record describes the catch data from the Marine National Facility (MNF) RV Investigator voyage IN2023_V05, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 1)." The voyage took place between 27 June 2023 and 29 July 2023 (AEST), departing from Hobart and returning to Hobart. The dataset contains catch data for specimens collected by Museums Victoria during the voyage. Records include species identification, counts and/or weights, and are linked to sampling metadata such as station number, location (latitude and longitude), depth, time, and gear type. These data provide a baseline for assessing species composition, abundance, and distribution, supporting long-term monitoring, research, and management of the southeast Australian marine ecosystem.

This dataset is focusing on using environmental DNA (eDNA) to measure offshore marine biodiversity in Southeast Australia. The eDNA samples were collected during two SEA-MES voyages aboard the RV Investigator: IN2023_V05 (July 2023) and IN2024_V03 (May 2024). Sampling sites spanned the continental shelf, from Tasmania to Batemans Bay, NSW, with water collected from both surface and bottom depths via Niskin bottles and a deep-tow camera system. A total of over 100 CTD deployments were conducted across these sites, providing comprehensive spatial coverage. The dataset includes processed eDNA metabarcoding results, containing sequence read counts and taxonomic data derived from DNA sequences, with a focus on fish but extending across the full tree of life, including bacteria, invertebrates, and vertebrates. Over 180 million sequences were generated, using a variety of markers such as mtDNA 16S (fish), mtDNA COI Leray (metazoans), and V4 18S (eukaryotes). This dataset is valuable for understanding marine biodiversity in southeast Australia and advancing offshore eDNA techniques.

This dataset comprises still images collected using a deep-towed camera during the RV Investigator voyage IN2023_V05, titled "Untangling the causes of change over 25 years in the southeast marine ecosystem (SEA-MES Voyage 1)." This was the first survey of the South East Australian Marine Ecosystem Survey (SEA-MES) Project. The voyage was conducted between 27 June 2023 and 29 July 2023 and sampled the south-eastern Australian continental shelf and upper slope from the Freycinet Peninsula to north of Eden. The deep-towed camera was deployed along survey transects to capture imagery of benthic habitats and associated fishes. The images provide visual records of seafloor characteristics, habitat structure, and faunal assemblages, supporting the classification of habitat types and identification of fish species. The dataset supports assessments of habitat–fauna relationships, validation of trawl catch data, and long-term monitoring of ecosystem change within the SEA-MES study region, contributing to the establishment of new biological and environmental baselines for south-eastern Australia.

This dataset comprises the Multi-net plankton sampling collected during the SEA-MES program across four RV Investigator voyages (IN2023_V05, IN2024_V03, IN2024_V05, IN2025_V04). A total of 173 Multi-net operations were conducted, using 100 µm and 500 µm mesh nets to collect depth-stratified samples through the water column, capturing both day and night to assess diel vertical migration. The dataset includes 560 samples from 100 µm nets and 140 samples from 500 µm nets, providing information on zooplankton composition, biomass, and community structure, including 58,246 individuals from 105 genera and 70 families identified to date. These data provide a detailed view of pelagic biodiversity across the south-eastern continental shelf and upper slope of Australia.