What we do

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OTN’s work


The Ocean Tracking Network (OTN) is a global aquatic research, data management and partnership platform headquartered at Dalhousie University in Halifax, Nova Scotia, Canada.

OTN’s mission is to inform the stewardship and sustainable management of aquatic animals by providing knowledge on their movements, habitats and survival in the face of changing global environments.

Since 2008, OTN has been deploying state-of-the-art ocean monitoring equipment and marine autonomous vehicles (gliders) in key ocean locations and inland waters around the world. OTN’s technical capabilities expanded in 2020 with the addition of remotely operated vehicles (ROVs) and side scan sonar systems.  

Researchers around the world are using OTN’s global infrastructure and analytical tools to document the movements and survival of aquatic animals in the context of changing ocean and freshwater environments.

Knowledge generated through OTN collaborations is used provincially, federally and internationally to help guide the management of valued aquatic species and the sustainable use
of ocean and freshwater resources. 


Animal tracking and ocean monitoring 

From monitoring the global movements and behaviours of sharks to better inform and protect beachgoers, to supporting community-driven efforts to track commercial species, to assisting in the design of MPAs and transboundary fisheries management practices, OTN is fostering international-scale collaboration and transforming aquatic species research into knowledge that benefits everyone.


Methods of data collection 


While tracking uses sophisticated technology, its purpose and concepts are quite simple.

Electronic tags

Scientists tag a wide range of aquatic species with uniquely coded electronic tags. These tags range in size from a chickpea to a AA battery. They are surgically implanted or externally attached to the animal and can operate for up to 10 years at a time.

Acoustic tags

Acoustic tags are transmitters that allow researchers to track the movements of animals in both freshwater and marine environments. Each tag emits a unique code that is detected and stored by an acoustic receiver when the animal travels within detection range of the unit.

Satellite tags

Satellite tags transmit data from tagged animals directly to satellites when the animal surfaces (attached to the heads of seals or mounted on the dorsal fins of sharks) or when the tag pops off the animal on a preprogrammed date and floats to the surface. The data is then relayed to researchers in near-real time.

PIT tags

Passive integrated transponders (PIT) are rice grain-sized tags that  operate using radio frequencies, and are primarily used for electronic telemetry on animals in freshwater environments.


Transceivers act as both a transmitter and a receiver. Large aquatic animals outfitted with this specialized combination allow researchers to track animal associations and predator-prey interactions between other tagged aquatic animals. Transceivers also collect oceanographic data from sensors on the tags animals are carrying, and, together with animal aggregations, help identify hotspots—areas of high productivity in marine ecosystems.


OTN acoustic receivers are typically arranged approximately 800 metres apart on the sea floor to form an array, or a ‘listening line’, but can also be affixed to existing structures or floating buoys. When an acoustically tagged animal swims within detection range of a receiver, the acoustic signal from the tag is recorded. The receiver stores the tag’s ID, as well as the date, time and data from any sensors that may be on the tags to help answer an investigator’s study questions.

Acoustic tags, transceivers and receivers can be mounted on sophisticated platforms—such as autonomous ocean-going vehicles known as gliders—to monitor and collect data on temperature, depth, salinity, currents, chemistry and other oceanographic variables. Gliders can travel thousands of kilometres for months at a time, collecting data on marine animals and ocean ecosystems. The data collected complements information gathered on aquatic animal movements to develop a foundation for understanding the impact of changing ecosystems on aquatic animals.

The OTN database holds all of the global data records submitted by OTN collaborators, providing quality controlled, secure records that can be applied to many environmental research studies.

Adding your project to OTN connects you and your research to a global community of telemetrists. There are many benefits of using the OTN Data Centre (OTNDC). Learn more here.

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