The species had not been seen in the North Sea since 1963. From then on, it had been repeatedly noted further north. A network of European scientists analyzed the movements of these fish using transmitters and beacons. Recently, a Danish institute was able to report hundreds of bluefin tuna at the intersection of the Baltic and North Seas. “These studies showed that bluefin tuna used these two seas as feeding areas, especially in summer and autumn.”
This fish can measure up to 3.5 meters and weigh 750 kg. The species was long considered threatened, but is now in the process of recovery thanks to the reduction of fishing quotas and the fight against illegal fishing.
However, scientists remain cautious; the long-term reestablishment of the species will depend on the success of reproduction in the Mediterranean. “As the animals returning to the North Sea today only belong to a few age groups, they are particularly sensitive to fishing pressures.”
