Keyword

SHARKS/RAYS/CHIMAERAS

21 record(s)
 
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  • This record relates to communications outputs of a research project which centered around working with Indigenous communities to raise the profile of the Largetooth Sawfish and support community driven conservation efforts. Some of the items are intended for public viewing (videos and educational signage); but the other outputs are intended for use by the Indigenous communities involved in the sampling (trip reports and Malak Malak annual floodplain sampling protocol and I-Tracker data collection application).

  • Australia is home to a quarter of the world’s cartilaginous fishes (Class Chondrichthyes) with 328 species consisting of 182 sharks, 132 rays, and 14 chimaeras. Australia’s first Shark Action Plan aims to provide a comprehensive and consistent review of the extinction risk of all cartilaginous fishes (hereafter ‘sharks’) occurring in Australian waters, to provide a benchmark from which changes in population and risk can be measured, and to help guide management for their conservation. This Action Plan also serves to raise the profile of their diversity and conservation needs. This volume includes a taxa profile for each of the 328 species occurring in Australian marine and inland waters, including external territories. Each species’ extinction risk was assessed by applying the IUCN Red List Categories and Criteria at the national level. Assessments of extinction risk consider all available information on a species’ taxonomy, distribution, population status, habitat and ecology, major threats, use and trade, and conservation measures. The IUCN Red List Categories and Criteria utilise a series of thresholds to evaluate extinction risk based on population size reduction, geographic range, population size, or the probability of extinction. Species were assessed against the five Red List criteria; to qualify for one of the three threatened categories (Critically Endangered, Endangered, or Vulnerable), a species had to meet a quantitative threshold for that category in any of the five criteria. The overall status of sharks in Australia is characterised by a relatively low level of extinction risk and a high level of secure species. Of the 328 species, 12% are threatened (39 species: 22 sharks, 17 rays; no chimaeras are threatened); 10% are Near Threatened (32 species: 18 sharks, 13 rays, 1 chimaera); 70% are Least Concern (231 species: 123 sharks, 95 rays, 13 chimaeras); and, 8% are Data Deficient (26 species: 19 sharks, 7 rays, no chimaeras are Data Deficient). No species are Extinct or Extinct in the Wild. Each taxa profile specifies two sets of actions for a species: actions to address knowledge gaps, and actions to maintain, secure, and if necessary, recover the population. To improve the ability to accurately assess the status of species, and ultimately, better conserve and manage them, all species treated in this Action Plan require some knowledge gaps be filled. Knowledge gaps are divided into five themes, each of which improves the information base from which to assess status: taxonomy, distribution, population trend, life history, and connectivity. Conservation actions are provided for each species, regardless of the status assigned them in this Action Plan. While threatened species require immediate action to conserve, manage, and recover their populations, Least Concern species also require action to maintain their secure status. Data Deficient species require action to understand various aspects of their population, but since an assessment as Data Deficient acknowledges the possibility that future research may show that a threatened classification is appropriate, action is also needed to minimise or mitigate threats until such time as more information is available to show that the species is not threatened. Finally, an overarching recommendation is provided for each threatened species. This includes the recommendation that five species be considered for listing on the Environment Protection and Biodiversity Conservation Act (EPBC Act), three species be considered for up-listing, and two species be considered for down-listing. An additional 12 threatened species have been identified as priorities for data collection where further data are required to strengthen the evidence-base underlying their status determinations. These species are priorities for research and monitoring to provide data to support inferred or suspected population reductions or continuing declines identified in the Action Plan. The implementation of the recommendations and actions in this Action Plan will require an ongoing and enhanced investment in science and management which will help secure the future of Australia’s sharks, rays, and chimaeras.

  • 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 2023 project "Delineation and estimation of the Maugean skate population in Macquarie Harbour, Tasmania". No public data outputs are planned for this project. -------------------- 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]

  • Redmap is a primarily a website that invites the community to spot, log and map marine species that are uncommon in their region, or along particular parts of their coast. The information collected is mapped and displayed on the site, demonstrating, in time, how species distributions may be changing. Sightings are divided into two categories – those with a photo that can be ‘verified’ by a marine biologist, and sightings without photos that we call community sightings (anecdotal). All the information collected, with and without photos, is mapped and will be used in the following years to map out a ‘story’ of changes occurring in our marine environment. The main data collected includes the species sighted (normally selected from a list comprising preselected species of interest), the location, date/time and activity being undertaken. Other optional information gathered include biological data such as sex, size and weight and environmental data such as water depth and temperature and habitat. This record is associated with live data (and will subsequently change over time) and spatial elements have reduced accuracy. It is also subject to a three year embargo (ie. does not contain data less than three years old). If you wish to discuss obtaining a citable, static dataset, that is current and/or contains accurate spatial elements, please see Point of Contact.

  • Redmap is a primarily a website that invites the community to spot, log and map marine species that are uncommon in their region, or along particular parts of their coast. The information collected is mapped and displayed on the site, demonstrating, in time, how species distributions may be changing. Sightings are divided into two categories – those with a photo that can be ‘verified’ by a marine biologist, and sightings without photos that we call community sightings (anecdotal). All the information collected, with and without photos, is mapped and will be used in the following years to map out a ‘story’ of changes occurring in our marine environment. The main data collected includes the species sighted (normally selected from a list comprising preselected species of interest), the location, date/time and activity being undertaken. Other optional information gathered include biological data such as sex, size and weight and environmental data such as water depth and temperature and habitat. This record is associated with live data (and will subsequently change over time) and spatial elements have reduced accuracy. It is also subject to a three year embargo (ie. does not contain data less than three years old). If you wish to discuss obtaining a citable, static dataset, that is current and/or contains accurate spatial elements, please email enquiries@redmap.org.au.

  • Redmap is a primarily a website that invites the community to spot, log and map marine species that are uncommon in their region, or along particular parts of their coast. The information collected is mapped and displayed on the site, demonstrating, in time, how species distributions may be changing. Sightings are divided into two categories – those with a photo that can be ‘verified’ by a marine biologist, and sightings without photos that we call community sightings (anecdotal). All the information collected, with and without photos, is mapped and will be used in the following years to map out a ‘story’ of changes occurring in our marine environment. The main data collected includes the species sighted (normally selected from a list comprising preselected species of interest), the location, date/time and activity being undertaken. Other optional information gathered include biological data such as sex, size and weight and environmental data such as water depth and temperature and habitat. This record is associated with live data (and will subsequently change over time) and spatial elements have reduced accuracy. It is also subject to a three year embargo (ie. does not contain data less than three years old). If you wish to discuss obtaining a citable, static dataset, that is current and/or contains accurate spatial elements, please see Point of Contact.

  • 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 dataset describes grey nurse shark (Carcharias taurus) listed, recognised and candidate aggregation sites in Australian waters, together with supporting individual acoustic-detection summaries from monitored aggregation sites. It consolidates previously documented site-level information on known, listed and candidate aggregation areas with time-series evidence of acoustically tagged shark detections. The project reviewed existing information on grey nurse shark aggregation sites and developed a revised definition for assessing aggregation status. Under this definition, an aggregation site is a discrete area where multiple grey nurse sharks are observed on a regular or predictable basis and where one or more behavioural functions may be inferred, including migration, resting, reproduction, feeding or undefined aggregation. The project also collected new survey and monitoring evidence from selected areas of potential grey nurse shark use, including Barwon Banks and the Hards in Queensland, Outer Gibber Reef in the Hunter Marine Park, and potential habitat in Gippsland, Victoria. These newly surveyed areas were not classified as confirmed aggregation sites as further monitoring is required to assess whether they support regular or predictable use by multiple grey nurse sharks. The data provided by this record include: • Aggregation-site data: a consolidated table of listed, recognised and potential grey nurse shark aggregation sites and associated information. • Individual detection data: collated acoustic telemetry detection summaries for tagged grey nurse sharks at monitored aggregation sites.

  • This record provides an overview of the NESP Marine and Coastal Hub Research Plan 2024 project "Grey Nurse Shark aggregations". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Grey nurse sharks (Carcharias taurus) are protected in Australian Commonwealth waters. Under the EPBC Act, the eastern Australian population is listed as Critically Endangered, while the western Australian population is listed as Vulnerable. The species aggregates at particular sites along migration routes, but existing definitions and criteria for “key aggregation sites” require refinement to support consistent assessment across eastern and western Australia. This project collated existing information on recognised grey nurse shark aggregation sites and potential new sites where sharks have been observed to gather. It reviewed occupancy patterns, existing survey evidence and western population data to refine the definition of a key aggregation site and develop criteria for assessing whether sites should be listed, delisted or prioritised for further investigation. Field and data activities focused on areas where information was limited or where potential new aggregation sites had been identified. These included surveys in Victorian waters near Corner Inlet using ROV and eDNA methods in partnership with Gunaikurnai Land and Waters Aboriginal Corporation; community engagement with dive, fishing and freediving groups to improve reporting of observations; an initial BRUV survey of a reef system in Commonwealth waters in Hunter Marine Park; expanded acoustic receiver coverage at Barwon Banks in Queensland; and review of potential aggregation sites in Western Australia. The project outputs provided Commonwealth and state management agencies with a clearer, more defensible basis for identifying and assessing grey nurse shark aggregation sites. The resulting information supported consistent evaluation of existing and potential sites, prioritisation of future surveys, and improved conservation planning for both eastern and western grey nurse shark populations. Outputs • Spatial information on key Grey Nurse Shark aggregation sites [dataset] • Final project report [written]