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]

Antarctic Landfast sea ice (fast ice) is important climatologically, biologically and for logistics for short time-scale anomalies. Until recently, there hasn’t been an accurate, high-resolution fast ice extent dataset which can support an analysis on drivers of fast ice and most studies only investigate fast ice on limited regions of Antarctica in a limited time scale. There is a need to extend the spatial and temporal studying coverage to provide detailed information on the Antarctic coast over a longer period. This is the first detailed analysis to identify and quantify correlation between the environmental anomaly and fast ice anomaly mainly in the east Antarctic coast. By examining regional/local fast ice extent in in east Antarctic coast in the context of the broader and/or remote-teleconnected atmospheric circulation/properties using spatial correlation techniques, a strong correlation between NINO3 region and Lützow-Holm Bay fast ice and similar and significant correlation of regional scale factors from Lützow-Holm Bay to Mawson Coast mainly are found. The results of this thesis suggest that the pack ice, atmospheric factors and oceanic factors are important for interpreting fast ice anomalies. To identify and quantify correlation between the pack ice, temperature at 2m, wind at 10m, snow fall anomaly, sea surface temperature anomaly, ocean heat content anomaly and fast ice anomaly, backward multiple linear regression is conducted to demonstrate some predictive fast ice driver information by quantifying the correlation between different drivers and fast ice anomaly. The multiple linear regression also suggests that oceanic influences including pack ice are generally more important than atmospheric influences. Future experiments could be conducted to interpret fast ice anomalies in the context of the ocean mainly.

This record provides an overview of the NESP Marine and Coastal Hub small-scale study - "A national inventory of implemented nature-based solutions to mitigate coastal hazards". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Climate change and population growth are accelerating the need for diverse solutions to coastal protection. Traditionally, shorelines are armoured with conventional "hard" or "grey" engineering structures such as seawalls which are non-adaptive and come with significant economic, environmental and social costs. While hard structures will continue to have a place in coastal protection, alternative methods that are more sustainable and climate-resilient should be more broadly adopted into the future where appropriate. Living shorelines harness natural ecosystems to reduce coastal erosion and flooding and provide co-benefits such as carbon sequestration. They may consist of dunes, wetlands and biogenic reefs: either alone (‘soft approach’) or in combination with hard structures (‘hybrid approach’). To date, nature-based solutions have been underutilised in Australia, due at least in part to decision-makers needing clearer guidelines for when a soft, hybrid or hard coastal defence approach is most appropriate. This resulted in the publication of a foundational guide (led by Morris and Swearer and delivered under ESCC Hub Project 5.9: Natural habitats for coastal protection and carbon sequestration) to inform the national use of nature-based methods for coastal hazard risk reduction. In the process of producing these guidelines, the lack of a national inventory of coastal protection projects already using nature-based methods was identified by end-users as a priority to enable their wider adoption as an adaptation strategy in Australia. This project generated an online inventory of all current and planned on-ground actions by coastal land managers that have implemented a nature-based solution (NBS) to mitigate coastal hazards. From this, the "Living Shorelines Australia" (https://livingshorelines.com.au) database was created. This inventory is the first step in identifying best practice, which will inform the future development of detailed technical design guidelines for implementing different nature-based methods in Australia. Outputs • A national inventory of existing implemented nature-based solutions to mitigate coastal hazards [dataset] • Final Project Report [written]

The fatty acid content and composition of the Antarctic krill Euphausia superba Dana, 1850 were investigated using samples collected by a commercial fishing vessel. This dataset allowed comparison between seasons, years (2013–2016), and different fishing locations. Quantities of omega 3 fatty acids 20:5n-3 and 22:6n-3 (mg/g dry mass; DM) were highest in autumn and decreased through winter to reach a spring low. Quantities of the flagellate marker 18:4n-3 and diatom marker 16:1n-7c were variable and did not display the same seasonal fluctuations. In summer, krill had high percentages (% total fatty acids) of 20:5n-3 and 22:6n-3, total PUFA, and low 18:1n-9c/18:1n-7c ratios, indicating a more herbivorous diet. Krill became more omnivorous from autumn to spring, indicated by increasing ratios of 18:1n-9c/18:1n-7c and percentages of Σ 20:1 + 22:1 isomers. Bacterial fatty acids (Σ C15 + C17 + C19 isomers) were minor components year-round (0.9–1.8 %). Seasonal levels of herbivory and omnivory differed between years, and levels of specific fatty acid ratios differed between fishing locations. The fatty acid 18:4n-3 was a major driver of variability in krill fatty acid composition, with no obvious seasonal driver. This is the first study to report krill fatty acid data during all four seasons over consecutive years. This large-scale study highlights the value of using fisheries samples to examine seasonal and annual fluctuations in krill diet and condition.

Landings surveys of bycatch of Solegnathus assessed from interviews with fishers in important fishing ports of NSW and Victoria, ranging from the Brunswick-Byron co-op to Portland in Victoria.

In coastal ecosystems, seaweeds provide habitat and a food source for a variety of species including herbivores of commercial importance. In these systems seaweeds are the ultimate source of energy with any changes in the seaweeds invariably affecting species of higher trophic levels. Seaweeds are rich sources of nutritionally important compounds such as polyunsaturated fatty acids (PUFA) and are particularly rich in long-chain (≥ C20) PUFA (LC-PUFA). In southern Australia, the ‘Great Southern Reef’ has one of the most diverse assemblages of seaweeds in the world, which support highly productive fisheries and have been recognised as a promising resource of omega-3 LC-PUFA. Despite this, there is little information on the biochemical composition of most species and how it varies between sites and seasons. To address this knowledge gap, we undertook a survey to assess seasonal variability in the biochemical composition (fatty acids and nitrogen content) of abundant understory seaweeds across three sites in eastern Tasmania. The availability of nutritional compounds differed between sites and was primarily driven by differences in the biomass and the biochemical composition of the nutritious red seaweeds at each site. This variability may explain regional differences in the productivity of commercial fisheries. At the species level, seasonal changes in fatty acid composition were highly variable between species and sites, indicating that multiple environmental drivers influence fatty acid composition of seaweeds in this system. This finding suggests that commercial harvest of seaweeds from eastern Tasmania will need to consider species and site-specific variability in fatty acid composition.

A 12-month program was developed and implemented in order to obtain baseline information on water quality (salinity, water temperature, dissolved oxygen, turbidity, pH, dissolved nutrients, silica), ecological condition as shown by Chlorophyll a, benthic macroinvertebrates, pathogens, and habitat extent determined from habitat mapping. Five key estuaries and coastal waters were assessed in the Southern NRM Region of Tasmania. The data represented by this record was collected in North West Bay.