Application for Scientific Permit – Available for Public Comment
Public comment on the following application for a Scientific Research (Fauna) Permit is open until 9 July 2025.
Applicant:
University of Tasmania
Species/Taxon:
Maugean skate, Zearaja maugeana
Location:
Macquarie Harbour, western Tasmania.
Study sites will be distributed throughout the harbour in areas known to be inhabited by Maugean skate - this includes sites within the World Heritage Area.
Title of research:
Macquarie Harbour Maugean skate population status and monitoring
Aim of project:
The goals of this study are to 1) continue previous-applied population monitoring protocols for the Maugean skate, while 2) developing new methods to increase survey effectiveness and efficiency.
These objectives address urgent questions regarding the status of the species and long-term population trends, which will help inform conservation action in the future.
Justification:
Maugean Skate (Zearaja maugeana) are only known from two isolated estuarine systems located on the west coast of Tasmania, representing one of most restricted distributions of any elasmobranch. The species is listed as Endangered by the IUCN and a conservation action plan has been developed by the State government and released in 2024.
A recent study (Moreno et al. 2020) showed the vulnerability of early life stages to the changing environmental conditions, long-term changes in the size structure of the population, and the mortality of some individuals following significant environmental events. Collectively, these highlight the vulnerability of the Maugean Skate and the need to consider further conservation action to support the persistence of this unique micro-endemic species. Consequently, maintaining an ongoing population monitoring program to assess the health of the Maugean skate population has been identified as an urgent need. This need was endorsed by government and industry stakeholders. Furthermore, monitoring data is invaluable when assessing the effectiveness of recently proposed conservation measures (e.g., habitat remediation and captive breeding).
Maximum likely numbers of individuals involved:
Based on previous research experience we estimate that seasonal surveys will capture less than 200 individuals per annum.
Activities undertaken and methods:
Skate will be captured using gillnets, with soak times for the gear restricted to under two hours (past research shows short soak times almost entirely reduce risk of incidental capture damage for the species). Individuals will be examined using minimally invasive techniques (e.g., ultrasonography, bioimpedance analysis), measured, tagged with an external identifier (dart tag), and released. These surveys will be conducted seasonally throughout the validity of the permit.
Fate of animals:
All animals will be released at the site of capture.
Likely impact on species involved (including any by-catch):
The capture and handling protocols in this study have been designed to be non-invasive and minimize risk to the animals. These procedures are the result of over 10 years of past research experience with the species.
Other fish species are likely to be captured in the nets. If alive, all incidental catch will be carefully removed from the nets and released. Any fish in poor condition will be humanely euthanized to reduce suffering in accordance with the methods dictated by the animal ethics committee.
Amendment:
The following amendments are proposed to the above study (approved permit TFA24272) and have been reviewed and approved by the University of Tasmania Animal Ethics Committee (Permit #30685).
1. Acoustic Tagging
The primary amendment involves the addition of acoustic telemetry to the ongoing monitoring program. Selected Maugean skate individuals will be implanted with acoustic transmitters, some equipped with environmental sensors. This will enable continuous monitoring of habitat use via a network of acoustic receivers strategically deployed throughout Macquarie Harbour. This methodology builds on previous IMAS research (e.g., Bell et al., 2016; Moreno et al., 2020) and will provide insights into spatial ecology, behavioural responses to environmental variables (e.g., temperature, salinity, dissolved oxygen), catchability trends and natural mortality for population viability analysis.
Between 50 and 80 adult, and up to 40 juvenile, Maugean skate will be surgically implanted with acoustic transmitters. Tagging will follow established protocols, using tonic immobility. Skates will be placed ventral side up on a foam mat with gill irrigation maintained throughout the procedure. A small incision will be made in the abdominal wall, the transmitter inserted, and the site sutured using sterile, absorbable monofilament sutures. Instruments will be cold sterilised and rinsed in distilled water prior to the procedure which will take approximately 2–3 minutes per animal. Individuals will be held in a tank of aerated seawater for a short period after the procedure and observed closely to ensure full recovery before being gently released back into the water.
2. Modification to dart tagging protocols
An additional, smaller external dart tag will be introduced alongside the currently used dart tag to enable the tagging of juvenile individuals under approximately 320 mm in total length, who are presently excluded from mark-recapture efforts. This adjustment will allow for tagging across a broader size range, thereby improving demographic representation and the accuracy of population estimates.
3. Sperm collection for cryopreservation
As part of a long-term conservation breeding strategy, sperm will be collected from mature males for cryopreservation. This is intended to facilitate future artificial insemination efforts and enhance genetic diversity in captive populations without the need to house multiple males. The procedure will be conducted while the animal is in tonic immobility with gill irrigation maintained. The cloaca will be held just above the waterline, and gentle pressure applied over the seminal vesicle region to express sperm through the urogenital papilla. Samples will be collected using sterile syringes or pipettes and transferred to sterile tubes. This method is minimally invasive and typically completed within 1–2 minutes.