This record provides an overview of the NESP Marine and Coastal Hub small-scale study - "Conservation of spotted handfish". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Spotted Handfish (Brachionichthys hirsutus) were once common across the bays and estuaries of South-eastern Tasmania. By 1996, however, populations had declined and the species was listed as Critically Endangered under Australia’s Environment Protection and Biodiversity Conservation Act 1999. The species is relatively short-lived, (5–10 years) and matures at more than two years’ old. This leaves a short window for reproduction, which relies on egg masses laid on seafloor structures such as stalked ascidians. If spawning fails, population declines may occur rapidly. With no planktonic life stage to aid dispersal, and low adult dispersal, outside recruitment to re-establish collapsed populations is unlikely. Analysis of 23 years of Spotted Handfish survey data (1997–2019) supported by previous NESP Marine Biodiversity Hub work (Project A10) helped develop a time-series of survey data, increasing biological understanding and contributing to effective management actions. This project recommenced surveys of multiple local populations, after a two-year gap, to ensure that the potential impacts of development of the Derwent estuary and surrounds handfish populations or their habitats can be detected. Included in the population surveying was identification of suitable locations to plant Artificial Spawning Habitats (ASH) where natural spawning structures have declined. This will continue to support the species' captive breeding program with industry and foster engagement with the indigenous and broader community through participation, talks, outreach, publications, and the National Handfish Recovery Team (NHRT). Outputs • A consolidated database of all available data on spotted handfish imagery, length frequency, and GPS regions to 2022 [time-series database] • Final Project Report, including a short summary of recommendations for policy makers of key findings [written]

This record provides an overview of the NESP Marine and Coastal Hub emerging priorities study - "Application of environmental DNA to survey Bathurst Harbour Tasmania for the endangered Maugean skate". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The Maugean skate (Zearaja maugeana) is listed as Endangered under Tasmania’s Threatened Species Protection Act and the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999. Its known population is small (~3,000 individuals, Macquarie Harbour, 2016) and highly restricted, having only been recorded in two isolated estuaries: Bathurst Harbour and Macquarie Harbour in south-western/western Tasmania. This constitutes one of the most limited distributions of any known extant elasmobranch. Although the skate was first discovered in Bathurst Harbour, most knowledge of the species stems from the Macquarie Harbour population. Only four individuals have been reported in Bathurst Harbour, with the last reported sighting in 1992. Environmental conditions in Macquarie Harbour have changed markedly since then due to anthropogenic activities in and around the estuary including historical mining, hydro-electric generation and alteration of natural river flows, and marine fish farming. Previous research has shown clear signs of population stress and evidence of detrimental impacts of degraded environmental conditions on the Maugean Skate in Macquarie Harbour. Understanding the potential population status of the Maugean Skate in Bathurst Harbour will assist in determining conservation actions. This study used Environmental (e) DNA to determine the presence/absence of Maugean skate in Bathurst Harbour, strengthening the evidence base for effective conservation plans and specific recovery actions. Outputs • Maugean skate eDNA sampling data and inferred species distribution (presence/absence) [dataset] • Final Project Report, including a short summary of recommendations for policy makers of key findings [written]

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 Emerging Priorities project "Modelling adult abundance and habitat distribution of Maugean skate". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The Maugean skate (Zearaja maugeana) is listed as Endangered under Tasmania’s Threatened Species Protection Act 1995 and the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. The species has one of the most restricted distributions of any extant elasmobranch, having only been recorded in Macquarie Harbour and Bathurst Harbour in western Tasmania. The Macquarie Harbour population is small (~3,000 individuals) and exposed to ongoing environmental pressures, making robust population assessment and habitat monitoring a high conservation priority. This project investigated Close Kin Mark Recapture (CKMR) as a priority method for estimating historical abundance and supporting long-term monitoring of Maugean skate in Macquarie Harbour, as identified in the species’ Roadmap of Agreed Actions and 2023 Conservation Advice. CKMR uses next-generation sequencing to identify close relatives among sampled individuals and model breeding population size, adult survival and population trends. A second project component modelled the distribution of critical Maugean skate habitat in relation to dissolved oxygen, temperature and depth. Telemetry data from tagged skates were combined with biophysical harbour models and habitat selection modelling to generate potential habitat maps for a 2017-18 hindcast period and forecast scenarios based on recent and evolving water-quality conditions. These maps were assessed against existing knowledge of skate habitat to identify critical areas within Macquarie Harbour and inform future spatial and temporal sampling strategies. Project outputs include independent population-assessment methods and hindcast/forecast habitat suitability maps for Macquarie Harbour. These outputs support conservation decision-making, evaluation of remediation scenarios, identification of critical habitat areas, and future monitoring and sampling design. Outputs • High-quality DNA sequences of Maugean skate [sequencing data] • Hindcast maps (2017-18) of potential Maugean skate occupation [spatial data] • Recent and forecast (evolving) maps of potential Maugean skate occupation under different management scenarios [spatial data] • Estimates of spawning stock abundance of the Maugean skate from CKMR analysis [data contained in written report] • Final project report [written]

White sharks are listed as vulnerable under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and actions to assist their recovery and long-term viability are prescribed in a national recovery plan for the species. A priority action is to develop an effective means of estimating the size of white shark populations and monitor their status (population trend). This would provide a scientific basis for assessing recovery actions, and for local policies governing human-shark interactions: an issue of significant public concern. NESP Project A3 provides a national assessment of the southern-western adult white shark population abundance and an update of the total eastern Australasian white shark population abundance and status in order to establish the efficacy of existing recovery actions and provide a scientifically sound and rational basis from which to inform policies that aim to balance conservation objectives and public safety. This record describes the individual DNA sequencing of over 500 animals for CK-MR analyses of SA/WA population tissue samples.

This record described kelp growth and ecophysiological data relevant to the thermal tolerance of specific warm-tolerant and 'normal' family-lines of giant kelp (Macrocystis pyrifera) from Tasmania, Australia. Australia’s giant kelp 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. For habitat 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 (Project E7, Marine Biodiversity Hub) 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. This work cultivated the warm-tolerant strains of giant kelp previously identified, along with giant kelp strains of normal tolerance, at both cool (16 °C) and warm temperatures (20 °C). The juvenile kelp was then harvested, and a suite of physiological traits that may be responsible for their differences in thermal tolerance were examined. These included nutrient usage (carbon and nitrogen content), cellular membrane processes (fatty acid contents), and photosynthesis (PAM fluorometry and photosynthetic pigments). The cultivation trials again illustrated the improved ability of the warm-tolerant strains to develop at stressful warm temperatures relative to normal giant kelp. This work demonstrated for their first time that the improved thermal performance of these strains may extend to the development and fertilisation of the earlier kelp ‘gametophyte’ life-stage. Despite the clear differences in growth between the two test groups, the physiological assessments illustrated a complex pattern of responses, some of which are contrary to expected based on prior knowledge of thermal performance in kelps. Nonetheless, these results indicate that the warm-tolerant strains of giant kelp have a greater capacity to alter the composition of their fatty acids and may be more efficient users of nitrogen (a key nutrient for growth and development). This new information will help inform ongoing kelp breeding and selection programs for future-proofing kelp restoration in Australia and globally. The improved understanding of the physiology of kelp thermal tolerance might also help with identifying individuals and populations of Macrocystis, and other kelps, that may be resilient to (or especially threatened by) ocean warming and climate change.

The Maugean Skate Zearaja maugeana is a micro-endemic species known from only two isolated estuaries, Bathurst and Macquarie Harbours in southwestern/western Tasmania. This constitutes one of the most limited distributions of any known extant elasmobranch. As a result, the species is listed as ‘Endangered’ under the Threatened Species Protection Act (Tasmania) and the Environmental Protection and Biodiversity Conservation Act (Commonwealth). Even though it was first discovered in Bathurst Harbour, most of what is known about the species comes from the Macquarie Harbour population. Only four individuals have ever been reported in Bathurst Harbour, with the last known sighting occurring in 1992. This study used environmental DNA (eDNA) to determine the presence/absence of the Maugean skate in Bathurst Harbour on the southwest coast of Tasmania. Water samples were collected from the seafloor in Bathurst Harbour in November 2021 and February 2022, and in Macquarie Harbour (control samples) in December 2021. Samples were filtered using a self-preserving eDNA sampling system. Following each survey DNA from the samples was extracted and analysed through qPCR amplification. Mitochondrial primer pairs from two gene regions were used to detect the presence of Maugean skate DNA in the samples. Where possible, positive detections were sequenced, and their identity verified.

This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2023 project "Delineation and estimation of the Maugean skate population in Macquarie Harbour, Tasmania". For specific data outputs from this project, please see child records associated with this metadata. -------------------- The Maugean skate (Zearaja maugeana) is now only found in Macquarie Harbour on Tasmania’s west coast, which has a long history of environmental degradation. The species is listed as Endangered under Commonwealth and Tasmanian legislation, and its restricted distribution, small population size, and exposure to degraded environmental conditions make population monitoring a high conservation priority. Recent research suggests that the Macquarie Harbour population may be declining. However, existing abundance estimation methods are inadequate because the species is cryptic, capture-based methods pose risks to skate health, and conventional optical surveys are limited by the harbour’s shallow, stratified, and highly turbid conditions. This project developed and tested new approaches to estimate and monitor the Maugean skate population using next-generation genetic sequencing and novel imaging technologies. Non-invasive acoustic methods (adaptive resolution imaging sonar (ARIS), synthetic aperture sonar, performed better than optical approaches (LiDAR, conventional video), under Macquarie Harbour conditions. ARIS was identified as the most suitable image-based monitoring tool for future population surveys. The genetic component generated the first reference-quality whole and mitochondrial genomes for the species and sequenced samples from 162 individuals. Genome-wide single nucleotide polymorphism (SNP) analyses showed that the Macquarie Harbour population has very low genetic diversity, which may influence how genetic risks are interpreted in recovery planning. The project produced new monitoring methodologies, genomic reference resources, and population genetic datasets to support future monitoring of Maugean skate abundance, population structure, and genetic health. The findings will inform conservation planning and evaluation of recovery strategies including captive breeding, translocation, and long-term genetic monitoring under changing environmental conditions. Outputs • Tissue sampling results and genome-wide population genetic structure [dataset] • Final project report [written]