Jan. 30, 2017
For Immediate Release
New study reveals first-of-its-kind data on Atlantic salmon migration
ASF research shows wide variety of behavior at sea
ST. ANDREWS – A study published this month in the peer-reviewed ICES Journal of Marine Science tracks 43 adult salmon as they leave the Northwest Miramichi River in New Brunswick and head to sea. This research is the world's first detailed look at the movement of multiple Atlantic salmon in the Gulf of St. Lawrence and Labrador Sea.
Results show that despite a shared home river and close genetic relations, Atlantic salmon follow multiple paths at sea, and exhibit individual behaviours. For example, one of the tagged fish was recorded diving to depths of greater than 900-metres, while others did not go below 40-metres.
"What this research shows us is that there is a large variation in Atlantic salmon movements at sea," said Jonathan Carr, ASF's executive director of research. "These fish utilize different habitats during their ocean migration and their success depends on conditions in many areas"
Data from four years, beginning in 2012 was used in this study. All 43 fish were fitted with a satellite tag behind their dorsal fin to measure depth, temperature, and light intensity. The Atlantic salmon used in the study were over 70 centimeters to accommodate the tags.
The satellite tags are programmed to pop off between 114 and 177 days after attachment. They then rise to the surface, connect with passing satellites, and transmit stored data.
This study also illustrates the dangers Atlantic salmon face in the ocean, and the technical challenges of marine tracking. Of the 43 satellite tags deployed, 24 transmitted data, and nine of those reporting tags showed movement patterns associated with species like sharks, meaning the fish were eaten.
The furthest swimmer almost reached Greenland, 1600-kilometres from the Miramichi, before the tag released. The top speed recorded among the sample group was 36-kilometres per day.
Previously it was believed salmon migration routes in the Labrador Sea were heavily influenced by ocean currents, but the tagged individuals in this study seemed relatively unaffected.
"Knowing more about the path Atlantic salmon take will allow us to focus conservation efforts by connecting the movement of individual salmon with what's happening at sea," said Jonathan Carr.
ASF will increase the number of fish tagged in future years and add new study rivers to the tracking program. We are working with the Canadian and U.S. federal governments to create a definitive scientific picture of Atlantic salmon at sea. Determining cause and specific areas of high marine mortality is key to conserving Atlantic salmon.
The lead author on this study, John Strom from the Arctic University of Norway, collaborated with ASF biologists and exclusively used data from ASF's tracking work. ASF regularly collaborates with and hosts scientists from around the world studying Atlantic salmon.
To arrange interviews, or for pictures and video, please contact:
Neville Crabbe – Director of Communications
Check out ASF's latest State of the Salmon report for information about populations and threats: