In 2023, the Centre for Environment, Fisheries and Aquaculture Science (Cefas) initiated the MAKTAG project, focusing on the internal tagging of Atlantic mackerel (Scomber scombrus) in the North Sea. This effort aims to enhance understanding of mackerel movements across the North Atlantic, complementing existing international programmes. ​

Atlantic mackerel are notable for their distinctive striped dorsal markings and inhabit a range extending from the Bay of Biscay to northern feeding grounds beyond Iceland and Norway.

While various surveys examine different life stages of mackerel, comprehending their migratory patterns necessitates tagging wild fish and releasing them back into the marine environment.

The tagging process involves inserting an inert Radio Frequency Identification (RFID) tag into a healthy mackerel, which is then released back into the ocean. This procedure has been approved by the Animal Welfare and Ethical Review Body (AWERB) at Cefas and is performed by trained scientists.

When a tagged mackerel is later caught by large pelagic fisheries, detectors installed in processing factories activate the battery-free tag and record its unique number. This system allows researchers to track the movement of mackerel from their release point to the location of recapture. ​

Since 2011, the Institute of Marine Research (IMR) in Norway has released over 600,000 tags across the west of the UK and Ireland to study mackerel movements and estimate natural mortality, contributing to sustainable exploitation through international stock assessments.

In September 2023, Cefas expanded this initiative to the North Sea. Collaborating with Norway, Cefas adopted similar tagging techniques, enabling tag detections across more than 20 detectors in six countries.
Over seven days at sea, using a Scottish commercial pelagic trawler, Cefas released 3,207 tagged mackerel in 2023 and, as of March 27, 2024, has received 99 recapture reports from international factory detectors.
The 2023 MAKTAG project served as a “proof of concept,” and Cefas is now exploring options for future tag deployments to increase the project’s impact by deploying more tags and collecting additional data from recaptures. ​

For more information visit: https://www.cefas.co.uk/impact/case-studies/introducing-maktag-internal-tagging-of-atlantic-mackerel-scomber-scombrus-in-the-north-sea/