Northern shark and ray research group

Project Leader: Joni Pini-Fitzsimmons

Mitigating the bycatch of threatened species in Australian gillnet fisheries is a major management challenge. In northern Australia, gillnet fisheries overlap with critical habitats for threatened and/or migratory sawfishes, river sharks, and devil rays listed under the Environmental Protection and Biodiversity Conservation Act 1999. These species, particularly sawfishes, are highly susceptible to entanglement due to their morphology and habitat use. Northern Australia supports the world’s most significant remaining populations of sawfishes and river sharks, making effective bycatch mitigation crucial for conservation efforts. At the same time, these fisheries provide sustainably harvested bony fish, contributing valuable seafood products to local and national markets. Addressing bycatch of non-target threatened species is one of the most pressing challenges for the sector. This project aims to test bycatch mitigation strategies in collaboration with industry and fisheries managers, focusing on reducing interactions with EPBC Act-listed sharks and rays in commercial gillnet fisheries across NT, WA, and QLD. This work is funded through the Threatened and Migratory Species Fisheries Bycatch Mitigation Program and the Fisheries Research Development Corporation, both administered by the Australian Government, with co-investment from CDU, Northern Territory Department of Agriculture and Fisheries, Western Australian Department of Primary Industries and Regional Development, and Industry Partners.

Alternative Gear Desktop Review (PDF, 1.68 MB)

Associated PhD Project

Assessing and mitigating threatened species bycatch in commercial gillnet fisheries in northern Australia

Emily Taljaard

Many commercial fisheries in northern Australia interact with a range of threatened species (TEPs), including marine mammals, reptiles, and sharks and rays. Bycatch of threatened sharks and rays in gillnet fisheries is a key conservation and management concern. Effective monitoring, bycatch mitigation, and tracking of TEPs can be used to quantify and enable the reduction of bycatch of threatened species. This project focuses on improving bycatch management and threatened species conservation by (i) evaluating the use of electronic monitoring systems to monitor interactions with TEPS, (ii) evaluating bycatch mitigation technology for reducing shark and ray TEPS bycatch in commercial gillnet fisheries, and (iii) investigating the movement of behaviour of Critically Endangered sawfish after release from capture in commercial fisheries. Through collaboration with commercial fishers across northern Australia, this research aims to enhance bycatch management and conservation outcomes for threatened sharks and rays.

This PhD Project also links to:

• Validation of commercial fisheries reporting using electronic monitoring project
• Sawfish monitoring: improved collection of fisher bycatch data project 

Project Leader: Joni-Pini-Fitzsimmons

Sawfish are among the most threatened groups of species on the planet, and their bycatch in Australian fisheries presents a significant challenge that requires evidence-based solutions to assess population status and reduce fishing impacts on these vulnerable species. This project aims to improve sawfish reporting and assess population abundance and stock structure through a large-scale collaboration between industry, government agencies, and research institutions across northern Australia. A key focus is building trust between researchers and the commercial fishing industry to enhance data collection and reporting. Industry-led sampling programs have been established under this project to collect tissue samples, which will be used to estimate sawfish abundance and stock structure through Close-Kin Mark-Recapture (CKMR). Post-release survival will be assessed using satellite tagging and improved reporting, with these data contributing to sustainability assessments of sawfish bycatch. This research responds directly to priorities identified in the Sawfish and River Shark Multispecies Recovery Plan, including improving estimates of bycatch, population connectivity, adult abundance, and post-release survival, ultimately informing management and conservation efforts in northern Australian fisheries. This project is supported with funding from the Australian Government’s National Environmental Science Program (NESP) and is led by CSIRO.

To read more about this project, visit: https://www.nespmarinecoastal.edu.au/project/3-11

Project leaders: Peter Kyne & Malak Malak Rangers

The Malak Malak Rangers and CDU have long collaborated on annual sawfish surveys and rescues on the Malak Malak Land Trust of the Daly River. The rescues are a unique partnership where Critically Endangered Largetooth Sawfish that become trapped in rapidly drying floodplain waterholes are captured and moved to the perennially flowing river. The rescues have so far saved 115 sawfish which would have died without this intervention. Once ranging globally in tropical waters, the Largetooth Sawfish has disappeared from most of its former geographic range with northern Australia being the last remaining stronghold for the species. Thus, the sawfish rescues are not only of local importance, but of global significance.

Associated Honours project

Relatedness in the Critically Endangered Largetooth Sawfish (Pristis pristis) of the Daly River

Samuel Amini

This project uses data collected from rescued sawfish over the last 13 years, through a longstanding collaboration between CDU and the Malak Malak Rangers. Using both nuclear and mitochondrial genomic markers, this project aims to understand how related these sawfish are (e.g., full-siblings or half-siblings), whether they share the same mother, and if related individuals tend to stay together. This project will improve the understanding of fine scale spatio-temporal patterns of relatedness within juvenile Largetooth Sawfish in the Daly River.

Daly River sawfish rescue poster (PDF, 556.5 KB)

Project leader: Joni Pini-Fitzsimmons

Effective fisheries monitoring is critical to ensuring sustainable fish stocks, protecting marine biodiversity, and managing the impacts of fishing activities. This project is a partnership with Wren Fishing Pty Ltd to develop and implement an electronic monitoring program to enhance the sustainability of their commercial fishing operations in Northern Australia and improve outcomes for threatened, endangered, and protected species (TEPS) bycatch. This work is part of the Wren Fishing Pty Ltd Fishery Improvement Plan, and will assist them in achieving Marine Stewardship Council (MSC) certification. 

Project leader: Peter Kyne

Northern Australia is the global stronghold for two of the world’s three river shark species. This unique group of threatened sharks are adapted to large tropical rivers and estuaries. Long term research has focused on the ecology and conservation of both the Speartooth Shark and the Northern River Shark. This has included an extensive acoustic receiver array in rivers of the NT’s Van Diemen Gulf monitoring the movements and survivorship of both species. Work on conservation genetics has revealed high levels of population structuring between rivers, and CSIRO-led and developed Close-Kin Mark-Recapture analyses have shown small population sizes. This work has been supported by the National Environmental Research Program and the National Environmental Science Program Marine and Biodiversity Hubs, and is a partnership between CDU, CSIRO, NT Fisheries, and Kakadu National Park.

Associated PhD project

Movement ecology and natural mortality of threatened river sharks: informing conservation planning

Julia Constance

This project is providing insights into the distribution, population resilience, movement ecology, and habitat use of river sharks in the Northern Territory. The research has unveiled a significant range extension for the Speartooth Shark to the Roper River in the NT's Gulf of Carpentaria – a region earmarked for significant water development. The first estimates of natural mortality in river sharks across all size classes, from neonate to adult, indicate that these species have limited ability to recover from population decline, due to extremely high natural mortality rates, particularly in younger individuals. Movement ecology, drivers of movements, and habitat use identifies priority habitats varying over temporal and spatial scales which will be vital for the conservation of river sharks into the future. Combined, this research highlights gaps in knowledge, significant new insights, and information critical to the conservation and management of river sharks and their habitats.

Project leader: Peter Kyne

The Clown Wedgefish is one of the most threatened and poorly known species on the planet. This ray was thought to be possibly extinct until it was recently rediscovered, and conservation action is urgently needed to secure this Critically Endangered species. This project aims to determine the geographic range and habitat of the Clown Wedgefish through a multi-disciplinary approach of fishery monitoring, interviews with fishers, and environmental DNA (eDNA) surveys. The project is a collaboration between CDU, the University of Southern Mississippi, and the National Research and Innovation Agency of Indonesia, with funding from the Save Our Seas Foundation.  

Associated PhD project

Examining catches of threatened rhino rays in Western Indonesia to inform conservation planning

Benaya Simeon

This project will provide information on the socio-ecological status of rhino rays based on local knowledge, fishery data, geographic range, habitat, and ecology. Data on fishing grounds and fishery captures will identify species distributions and priorities for management. The focus is on the highly threatened Clown Wedgefish, developing a conservation action plan for this species and more broadly for rhino rays throughout Indonesia.

PhD project: Adriana Gonzalez Pestana; Principal supervisor: Peter Kyne

Effective conservation and management strategies for sharks and rays are urgently needed, as these species face increasing threats. A key component of their protection is the identification and monitoring of critical habitats, which provide essential spaces for reproduction, feeding, resting, and movement. In this effort, citizen science plays a crucial role by contributing valuable data. This project aims to assess the impact of citizen science on shark and ray research and conservation. It will review global contributions, evaluate critical habitats in Asia, New Zealand, and the Pacific Islands, and identify key areas in Timor-Leste that require targeted management and protection. The identification of critical habitats will be undertaken within the Important Shark and Ray Areas (ISRA) framework, a project of the IUCN Species Survival Commission Shark Specialist Group. This PhD project will focus on the Asia and New Zealand and Pacific Islands Regions.

PhD project: David Drynan; Principal supervisor: Stephen Garnett

This project aims to identify and assess the empirical evidence on the efficacy of various approaches to shark bycatch mitigation globally for all shark species and across all commercial fishing gears. It will cover technical, operational, and regulatory approaches and how these are governed and implemented on the high seas with a focus on Tuna Regional Fisheries Management Organisations. The Conservation Evidence assessment framework will be used to provide a standardised and repeatable assessment method. The results and ratings can be used by fisheries managers to ascertain what approaches will be most beneficial for their circumstances and bycatch issues. Finally, these results will be used in a modelling exercise to identify the optimal suite of approaches to benefit an Australian shark species that is being impacted by commercial fisheries.

Project leader: Joni Pini-Fitzsimmons

Recreational fishing is a huge pastime in Australia, and there has been growing investment in associated infrastructure such as boat ramps and fish cleaning facilities to promote and support the activity. However, little data exists to inform the return on investment into these facilities. Likewise, monitoring data for recreational fishing effort and catch is severely lacking, hindering the implementation of informed management actions. Existing surveys provide broad-scale estimates of participation and catch of key species but lack the fine-scale resolution needed to assess local fishing activity and its ecological impacts. This project aims to address these gaps by using high-definition video monitoring enhanced with artificial intelligence to track facility use, quantify catches, and analyse the impact of fish waste disposal on marine wildlife, including coastal ray species. By providing robust data on fishing effort, species composition, and fish cleaning activity, this research will support better management of recreational fisheries and associated infrastructure.