Baltic Sea Tracking Network
KEY POINTS- Large-scale infrastructure for fish tracking in the Baltic Sea
- Network for collaboration and data sharing
Project overview
Participants
More related research
Global goals
- 14. Life below water
Short summary
Our infrastructure creates new opportunities to study fish migration and survival. Through strategically placed acoustic receivers, tagged individuals can be tracked across areas far beyond where they were originally tagged. Particular focus is placed on species such as salmon and brown trout.
Acoustic telemetry makes it possible to track the movements of individually tagged fish over time. The backbone of BSTN consists of acoustic receivers deployed along two lines between Sweden and Finland, in Kvarken and the Åland Sea. These strategically located detection gates register tagged fish moving between the Bothnian Bay, the Bothnian Sea and the Baltic Proper.
BSTN complements existing regional and local receiver networks and helps connect different acoustic telemetry initiatives around the Baltic Sea. A particular focus is on Atlantic salmon and brown trout and their migrations from rivers to the open sea and back. At the same time, the infrastructure can be used for other species and research questions, enabling movements to be studied over considerably larger geographical areas than is normally possible within individual studies.
A network for collaboration and data sharing
A central idea behind BSTN is that the infrastructure should provide benefits beyond individual research projects. By sharing detection data from BSTN through the Ocean Tracking Network (OTN) and European Tracking Network (ETN), researchers and managers can find out whether fish tagged in independent projects have been detected by BSTN receivers.In this way, BSTN, together with other receiver networks, creates opportunities to track fish across both geographical and administrative boundaries. The aim is for the resulting knowledge to contribute to a stronger scientific basis for the management and conservation of migratory fish populations in the Baltic Sea.
BSTN is operated jointly by the Swedish University of Agricultural Sciences (SLU), the Natural Resources Institute Finland (LUKE) and MidOcean via Voice of the Ocean (VOTO).
Project news
SLU launches large-scale fish tracking – aiming to provide new insights about fish in the Baltic Sea
Tagged salmon smolts in 2026
In 2026, a total of 750 salmon smolts were tagged in four river systems – Ume River, Lögde River, Ljungan and Testeboån – under management of SLU. These fish will be tracked in the Baltic Sea, where data on their survival and migration patterns will become available as part of next year’s data offload.
A similar initiative has been carried out by the Natural Resources Institute LUKE in four Finnish rivers flowing into the Gulf of Bothnia.
The film shows an example of fish tagging in Lögde River in June 2026:
