What is SMOLTRACK?
- SMOLTRACK is an EU-wide project coordinated by NASCO. By conducting field research and acquiring new data, SMOLTRACK acts as a platform for salmonid telemetry knowledge.
- SMOLTRACK allows international lead researchers to come together and share knowledge and best practices, with the goal of establishing an EU strategic salmon telemetry advisory group.
- SMOLTRACK will help scientists to learn about survival rates of salmon smolts during their migration through the lower parts of rivers, estuaries and coastal areas, providing data on smolt run timing and migration behavior.
- Ultimately, SMOLTRACK will inform future salmon management and conservation work on an EU level.
What are we doing?
Following
By attaching small transmitters to migrating fish, we are able to follow their movements as they swim downstream. To do so, we deploy listening stations in strategic points and have teams on-site equipped with antennas keeping record of the fish locations.
Learning
The tracking allows us to learn how many fish make it out of the river! Transmitters that stay in the same place for a long time or that disappear from the river without reaching the sea have likely been predated.
Protecting
Understanding the drivers behind the smolts' survival allow us to develop better management policies which aim to protect this important species and ensure the Atlantic salmon does not disappear from our rivers.
SMOLTRACK III is going live!
SMOLTRACK III will identify and evaluate the relative contribution of several factors responsible for smolt mortality. Ultimately, this will better inform fisheries management strategies that can optimise natural smolt production and consequently increase the number of wild adult returns. Shortly, SMOLTRACK III will have three main action targets:
- Work package 1: Understand the principal factors affecting smolt survival during their migration through the freshwater environment and transition to the marine environment.
- Work package 2: Evaluate the influence of temperature on smolt-migration timing.
- Work package 3: Assess the accuracy of telemetry-based assessments to provide information on smolt migration habits and survival.
Both WP1 and WP2 aim to provide a scientific basis to better inform fisheries managers in their implementation of measures to reduce negative pressures on juvenile production and out-migrating smolts. The timing of outmigration has been shown to correlate with sea temperature; we will test this on a large geographic scale and the results will also point to the effects of increasing sea temperatures on smolt survival. Additionally, the output from WP3 will enable the verification of the accuracy of telemetry-based survival studies and highlight any potential limitations of tagging to reliably assess salmonid migration. This will be done by comparing the migration and survival of two groups of smolts, one trapped and tagged at the moment of migration and the other tagged and released before migration starts.
Recent developments
Find out what our teams have been doing!
Where are we working?
SMOLTRACK is coordinated by North Atlantic Salmon Conservation Organization (NASCO) and currently has eight partners. This allows us to understand how different populations are keeping up with natural and anthropogenic pressures in a wide geographical range of conditions.

Denmark
Rivers Skjern & Storå
Technical University of Denmark
National Institute of Aquatic Resources





Spain
River Minho
General Directorate of Natural Heritage, Environmental Ministry, Galician Goverment
Website
Sweden
Rivers Göta älv & Högvadsån
University of Gothenburg
Department of Biology and Environmental Sciences