Movements of Australia’s large pelagic fish species are being affected by overfishing, climate change, and shifting ocean conditions. Until recently, it has been difficult to monitor their movements, as tagged fish had to be re-caught to obtain the data. This meant relying on fishermen landing tagged fish and reporting the tags. New acoustic tag technology means that fish movements can now be tracked around the coast in real-time. Acoustic technology has become one of the most popular methods to study movement in marine fisheries research. This is because fisheries and natural stock loss results in archival tag retrieval being as low as 5% making archival tags cost prohibitive.
Acoustic telemetry research is applied not only to fish species but covers also other marine taxa such as crustaceans, marine reptiles, and marine mammals. The purposes of acoustic tagging studies include determining movement and location, intra-specific behaviours such as schooling, timing and duration of spawning aggregations, timing and duration of mating pair formation, timing and frequency of predator-prey interactions, and dynamics of mixed species aggregations. The acoustic data will provide an understanding of the distance and speed at which migratory species travel, whether environmental factors affect their migratory instincts, and the sort of habitats selected by species for stopping over. This sort of information will lead to better management of Australia’s fisheries, resources and marine protected areas.
The acoustic telemetry research community typically uses two main types of deployments, large cross shelf arrays or curtains and clustered arrays around local areas such as reefs, headlands, and estuaries.
Instrumentation and Data
Acoustic telemetry is based on the development of uniquely coded tags which provide a way to track individuals over time. An acoustic tag is attached to or implanted into an animal and their movements are monitored using a network of acoustic receiver arrays. These arrays allow for animal positions to be determined as they pass receivers without the need for the tag to be retrieved.
The IMOS Animal Tracking Facility has deployed 16 arrays on the continental shelf in two main types of configurations, large cross shelf arrays or curtains and clustered arrays around local areas such as reefs, headlands, and estuaries. There are three arrays in collaboration with the Ocean Tracking Network (OTN) and 13 arrays as part of the national research infrastructure.
With receiver arrays in place researchers can track tagged animals as they pass by any of the IMOS receivers and thousands of co-invested receivers around Australia through the Animal Tracking Database and the Australian Ocean Data Network (AODN) Portal. Ideally, all researchers acoustically tracking marine organisms will contribute to the network. Researchers who share information will benefit by being provided with detections of their tags by receivers other than their own. The principle upon which this is based is that receiver data collected by all members of the network is pooled in the national database.
The national Animal Tracking Database has been developed to provide a platform for the Australian acoustic tracking community as a repository and data storage facility. Currently, the database incorporates deployed receivers at over 2000 locations nationwide with more than 4000 tagged animals that have generated over 65 million tag detections and growing. To date, 85 species covering five marine taxa have been tagged including crustaceans, chondrichthyes, osteichthyes, marine reptiles, and marine mammals. This collaborative effort gives each researcher the possibility to go beyond their locally or regionally important hypotheses regarding their targeted species. Thus, the database will provide the opportunity to aim at the big picture of species’ movements and may provide important baseline data for scientists to strategically plan investigations regarding a species’ biology and ecology as well as its ecosystem function.
Application of Data
In the first episode of the IMOS in MOcean video series, Dr Michelle Heupel from the Australian Institute of Marine Science (AIMS) talks about her research tracking sharks. Michelle describes the surprising results that demonstrated the long-range migration of bull sharks from Sydney Harbour to the Great Barrier Reef. Michelle explains how knowledge of marine animal movements can inform decisions about marine resource management, for example when planning or managing marine protected areas. This new video represents the work of the IMOS Animal tracking facility and how partners such as AIMS collect and use the data.
The World Heritage listed Ningaloo Reef in Western Australia is the focus of a marine research partnership between CSIRO and BHP Billiton Petroleum, that uses existing IMOS infrastructure at Ningaloo Reef. The five-year, jointly-funded $5 million research program will include both deep and shallow reef research, turtle and shark tagging, and three PhD scholarships. In addition, there will be opportunities for the local community to be involved in some aspects of the research. The program will use existing IMOS infrastructure at Ningaloo Reef. IMOS and CSIRO deployed the Ningaloo Reef Ecosystem Tracking Array in 2007: this is an array of acoustic receivers that detect tagged fish and animals, which aims to understand species' movements and habitat use on the unique coral reef ecosystem. There have been 3,778,546 detections since 2007, with the data stored in a database accessed via the Australian Ocean Data Network (AODN) Portal.
Student profile: Stephanie Brodie, Climate driven changes in the East Australian Current and their influence on the ecology and distribution of pelagic fish.
Steph is investigating how the oceanic variability off the east coast of Australia influences the movements and distributions of pelagic fish. Steph uses acoustic telemetry, integrated with the IMOS Animal Tracking Facility to determine the seasonal and inter-annual oceanic habitats of dolphinfish, Coryphaena hippurus, and yellowtail kingfish, Seriola lalandi. Acoustic telemetry is also used to examine fish use of fisheries enhancement structures (artificial reefs and Fish Aggregation Devices) deployed by NSW Fisheries. This project will advance the current knowledge of fish habitat association off the east coast of Australia. To read more about Steph's project click here.
The Animal Tracking Facility Publication Report - If you have any questions regarding the data, or corrections, or would like to add a publication or presentation that uses IMOS data please contact the IMOS office via email: publication(at)emii.org.au.
Dr Fabrice Jaine (Scientific Officer)
To watch online videos on how to use the Animal Tracking Database click here
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