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 endangered Maugean skate is now only found in Macquarie Harbour, which has a long history of environmental degradation, and recent research suggests that the population may be declining. However, our current abundance estimation tools are inadequate to determine population status and a new method is needed. This project will use next generation genetic sequencing and novel imaging survey tools to delineate and estimate the size of the Macquarie Harbour Maugean skate population to inform conservation strategies. There is also a need to investigate the evolutionary potential of the Maugean skate to adapt to the changing environmental conditions. This research will address these needs by examining the skate's genetic diversity and fine-scale population structure using whole genome typing, and developing a high-resolution dataset of genome-wide single nucleotide polymorphisms. This genetic approach will help inform adaptive management strategies, such as captive breeding, and enhance our ability to detect differentiated lineages with adaptive potential. Outputs • Tissue sampling results and genome-wide population genetic structure [dataset] • Adaptive resolution imaging sonar (ARIS) and lidar water column scanning [dataset] • Final project report [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. -------------------- This study will use Environmental (e) DNA to determine the presence/absence of the endangered Maugean skate (Zearaja maugeana) in Bathurst Harbour, Tasmania. Zearaja maugeana is classified as endangered based on its small population (~ 3000 individuals, Macquarie Harbour, Tasmania, 2016) and restricted distribution (Bathurst and Macquarie Harbours). Initially discovered in Bathurst Harbour in 1988, it has not been recorded there since 1992. Additionally, recent research suggests that the Macquarie Harbour population may be declining. As such, there is an urgent need to determine the current status of the Bathurst Harbour population. This research will address this need. Outputs • Maugean skate eDNA sampling data and inferred species distribution (presence/absence) [dataset] • Final technical report with analysed data, including a short summary of recommendations for policy makers of key findings [written]

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. In fact, only four individuals have ever been reported in Bathurst Harbour, with the last known sighting occurring in 1992. This study aimed to use eDNA to determine the presence of the Maugean skate in Bathurst Harbour on the southwest coast of Tasmania. Water samples were collected within 1 m from the sea floor 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.