The principle aim of this project was to map the fine-scale spatial distribution of key abalone habitat impacted by urchins in < 25 m water depth using multibeam acoustic imagery. Detailed substrate type (Pavement Reef, Megaclast Reef, Mixed Consolidated Sediment/Reef and Sand), and kelp coverage maps have been produced for the east coast of Tasmania. Large urchin barrens have been predicted and the minimum quantifiable unit of which small incipient barrens can be detected has been identified using this acoustic water column technique. This data provides a snapshot of the 2021 distribution of seafloor habitats and associated vegetation distribution, and will assist in the facilitation of strategic decision making for urchin control and abalone management. Data for download has been split by fishing block (22-24, 27-30). This record describes *FISHING BLOCK 23*. The following data products are available for download, for each fishing block: • 50cm resolution bathymetry • 50cm resolution substrate type (Seamap Australia classification) • bathymetry derivatives (seabed slope, curvature, rugosity, 1 and 2m contours) • water column data - 1m mean signal • water column data - 9m2 raw block statistic • water column data - vegetation likelihood classification See associated records for access to data from other fishing blocks (22, 24, 27, 28, 29, 30).

Genomic sampling locations and meadow indices for ribbon weed (Posidonia australis) and wire weed (Amphibolis antarctica) in Shark Bay (Gathaagudu)

This record provides an overview of the NESP Marine and Coastal Hub bridging study - "A photo-identification study of southern right whales to update aggregation area classification in the southwest of Australia". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The southern right whale (Eubalaena australis) is listed as Endangered under the Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act) and is subject to conservation listings in five Australian states due to severe population declines caused by historical whaling. The Southern Right Whale Conservation Management Plan 2011–2021 outlines the current status of, and threats to, the southern right whale in Australian waters and prioritises recovery actions during this period. The long-term vision for the recovery of this species in Australian waters is to increase the population size to a level that the conservation status improves, and the species no longer qualifies for listing as threatened under any of the EPBC Act listing criteria. The plan must be periodically updated to reflect new knowledge and prioritise the research needed to monitor population recovery and predict the impacts of threats such as climate change. Aerial surveys of southern right whales have been conducted across the southern Australian coast from Perth (W.A.) to Ceduna (S.A.) since 1993, as part of a long-term program to monitor the recovery, and inform the Conservation Management Plan (2011-2021), for this Endangered species. In Australia’s south-east, there has been little sign of recovery in southern right whale numbers following intense commercial whaling. A working hypothesis assumes separation between the ‘western’ and ‘eastern’ populations, largely due to loss of ‘cultural memory’ of whales migrating to the eastern range breeding areas. Given the relative paucity of animals that visit the southern Australian coast in areas other than south-west Australia, the western population is considered to represent the majority of the ‘Australian’ southern right whale population. The count data from these aerial surveys provide data on population trend and estimates of population size for the ‘western’ population, and hence the majority of the Australian southern right whales. Associated photo-identification data provide life history information (such as calving intervals) and connectivity between the ‘western’ and ‘eastern’ populations and contribute to the national southern right whale photo-id database: the Australasian Right Whale Photo-Identification Catalogue (ARWPIC). The 2020 aerial survey program recorded substantially lower numbers of whales than in the previous 13 years, and the lowest number of non-calving whales since the program started. This project conducted new aerial surveying in August 2021 to provide a relative estimate of annual population size for determining longer term population trends and contribute to determining if 2020 was an anomalous year or an indicator of some longer-term change to recent recovery rates and the female breeding cycle. Outputs • Aerial whale survey data (counts by size class, number, and location) - 2021-22 season [dataset] • Individual whale photo-identification data - 2021-22 season [imagery - published to ARWPIC] • Final Project Report including a short summary of recommendations for policy makers of key findings [written]

This record describes Remotely Operated Vehicle (ROV) imagery collected from within the Gascoyne Marine Park offshore northwestern Australia. The ROV SuBastian was used to conduct imagery transects on 20 dives across 16 stations, including 12 quantitative transects within the Cape Range Canyon. No quantitative transects were conducted in the Cloates Canyon due to delays caused by poor weather. SuBastian is equipped with a Sulis Subsea Z70 deep sea science camera, with 4K UHD 2160p optics and sensors for temperature, depth, conductivity and oxygen. The quantitative transects were run for 500 m upslope, ideally at a speed of 0.3 knots and an altitude of 2 m above the seafloor or rock walls. Still images were acquired every 5 seconds, with additional frames added manually as required. Still images from most transects were primarily annotated onboard using the RV Falkor’s private instance of SQUIDLE+, with some post-survey annotation conducted using the public instance of Squidle+ (http://squidle.org/). See post-survey report for full methodology. http://pid.geoscience.gov.au/dataset/ga/144204

This record provides an overview of the NESP Marine and Coastal Hub scoping study - "National Areas of Interest for Seabed Mapping, Characterisation and Biodiversity Assessment". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Seabed and marine biodiversity data are time-consuming and costly to collect, so it is imperative that acquisition is focused on areas that align with end user priorities. The value that different stakeholders place on seabed and biodiversity data can be difficult to determine. Therefore, a shared process for identifying survey priorities is required to ensure the maximum shared benefit of future survey investment across research users, funding agencies, infrastructure providers, as well as the wider marine research community. The project aimed to assist with the planning and prioritisation of marine surveys (both physical and biological) by scoping a prioritisation framework for marine surveys undertaking physical and biological seabed data collection in Australia. Focused workshops and targeted engagements with seabed mapping organisations were used to develop a standard set of metadata for agencies to define spatial Areas of Interest (AOI). The standard metadata were used in a prototype prioritisation framework that allows users to transparently and consistently rank and prioritise survey work or data delivery processes. The prioritisation is then based on rankings established by defined sets of criteria. A web-based AOI submission tool and mapping publication service was then developed for these defined areas as part of the AusSeabed Survey Coordination Tool. Adoption of this tool facilitates the development of an interim national areas of interest product to inform future survey planning. This product supports both the needs of Parks Australia's network Science Plans, and consideration of information needs for Indigenous Protected Areas within Sea Country. Outputs • National Areas of Interest polygon & interactive map [dataset] • Code for Survey Coordination Tool [Github Repo] • Final Report with Value Prioritisation Framework [written]

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.

Biodiversity assessments of invertebrates within seagrass (Amphibolis antarctica and Posidonia australis) transplant plots, compared to adjacent bare sand and healthy meadows at Middle Bluff, Dubaut Point and Useless Loop, Shark Bay.

Marine heatwaves are extreme events that can have profound and lasting impacts on marine species. Field observations have shown seaweeds to be highly susceptible to marine heatwaves, but the physiological drivers of this susceptibility are poorly understood. Furthermore, the effects of marine heatwaves in conjunction with ocean warming and acidification are yet to be investigated. To address this knowledge gap, we conducted a laboratory culture experiment in which we tested the growth and physiological responses of Phyllospora comosa juveniles from the southern extent of its range (43 - 31° S) to marine heatwaves, ocean warming and acidification. We used a "collapsed factorial design" in which marine heatwaves were superimposed on current (today's pH and temperature) and future (pH and temperature projected by 2100) ocean conditions. Responses were tested both during the heatwaves, and after a seven-day recovery period. Heatwaves reduced net photosynthetic rates in both current and future conditions, while respiration rates were elevated under heatwaves in the current conditions only. Following the recovery period, there was little evidence of heatwaves having lasting negative effects on growth, photosynthesis or respiration. Exposure to heatwaves, future ocean conditions or both caused an increase in the degree of saturation of fatty acids. This adjustment may have counteracted negative effects of elevated temperatures by decreasing membrane fluidity, which increases at higher temperatures. Furthermore, P. comosa appeared to down-regulate the energetically expensive carbon-concentrating mechanism (CCM) in the future conditions with a reduction in δ13 C values detected in these treatments. Any saved energy arising from this down-regulation was not invested in growth and was likely invested in the adjustment of fatty acid composition. This adjustment is a mechanism by which P. comosa and other seaweeds may tolerate the negative effects of ocean warming and marine heatwaves through benefits arising from ocean acidification.

This record provides an overview of the NESP Marine and Coastal Hub bridging study - "Future-proofing restoration & thermal physiology of kelp". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Kelp forests create complex habitats that support a diverse and productive community of marine life. They underpin coastal food-webs, fisheries, and a suite of other ecosystem services including nutrient and blue carbon cycling. Across much of the world, kelp forests are in decline and under threat from stressors including urbanisation, overgrazing, ocean warming, and marine heatwaves driven by climate change. Australia’s giant kelp (Macrocystis pyrifera) forests are listed as a Threatened Ecological Community under the Environment Protection and Biodiversity Conservation Act 1999. Habitat restoration is a potential tool for the conservation and management of giant kelp ecosystems. Given the direct impacts of climate change and ocean warming, there is growing recognition of the need for habitat restoration to be ‘future proofed’. For restoration to be effective, the cause of habitat decline must be understood and overcome. This is problematic when climate change is driving habitat loss since it cannot be reversed or ameliorated prior to restoration. A previous NESP project led by this team (NESP Marine Biodiversity Hub Project E7) identified warm-tolerant strains of giant kelp from remnant patches in eastern Tasmania, where the species has experienced precipitous declines due to ocean-warming. These strains have high potential to assist with ‘future-proofing’ kelp forest restoration, however it is still unclear what the physiological mechanisms are that provide their improved thermal tolerance. It is also unknown whether cross-breeding the identified warm-tolerant giant kelp strains will affect and potentially improve their thermal tolerance capacity. This project explored the physiology of kelp thermal performance, specifically the mechanisms potentially responsible for the warm water tolerance identified in particular giant kelp strains. It confirmed the improved ability of the warm-tolerant strains to develop at stressful warm temperatures relative to normal giant kelp, and demonstrated for the first time that their improved thermal performance may extend to the development and fertilisation. The outcomes progress toward the identification of populations of Australian kelp that may be resilient to (or especially threatened by) ocean warming and climate change. Outputs • Ecophysiological measurements from laboratory experiments of warm-tolerant vs average giant kelp genotypes [dataset] • Final Project Report including a short summary of recommendations for policy makers of key findings [written]