This adds new and important detail to the knowledge base around salmon marine migration and individual pathways. Taking the most likely migration route for this fish suggests that it has been covering an average of around 34km per day whilst in the sea before being recaptured.

This knowledge would not have been possible to obtain without the online database developed by the UK’s Missing Salmon Alliance (MSA) and Norwegian Institute of Marine Research (IMR). It follows coordinated efforts between these partners, the Icelandic Marine and Freshwater Research Institute (MFRI), the Directorate of Fisheries in Iceland, the French National Research Institute for Agriculture Food and Environment (INRAE), the French Observatory of Research on Diadromous Fish in Coastal Rivers (ORE DiaPFC) and the International Council for the Exploration of the Sea (ICES) working group on North Atlantic salmon.

PIT tags are increasingly being used in salmon and trout research and management programmes in countries around the North Atlantic, as in French long-term monitoring programs on index rivers. They are also routinely used in the stock assessment of commercially important marine fish species like mackerel and herring, requiring tag detectors to be operated at fish processing plants.