The research is being carried out in the Tys and Vest fjords, on the northern coast of Norway, in the Barents Sea, where hundreds of killer whales gather between November and January to feed on the schools of migratory herring. Killer whales catch virtually everything, from fish to walruses, seals, sea lions, penguins, squid, sea turtles, sharks, and even whales. They usually hunt in packs, which is why they have been called the sea wolves.

Killer whales are the largest representatives of the dolphin family. They are found all over the seas of the world (they are therefore regular visitors to the Strait of Gibraltar) although they prefer temperate and cold waters. Males can measure up to 9.5 meters in length and exceed 6 tons. The females, somewhat smaller, measure up to 8.5 meters and weigh around 5 tons. They can reach speeds of 50 km/h and travel 120-160 km daily. They have, like all dolphins, a sophisticated biological sonar system.

Toxicologist Hans Wolker, from the Polar Institute, has analysed the biopsies obtained using a dart that does not cause harm to the live animals of 10 specimens and, in recent days, he has been back in these fjords, before the Arctic night arrives, to take more samples, a very difficult activity and not without risks.

Referring to the results of the analyses that have already been carried out, Wolker says that the content of pollutants is the highest recorded so far, even higher than that found in polar bears. To put it graphically, Wolker says: “Name the first poison that comes to mind and I guarantee it will be present in the killer whales’ bodies. We can repeat the test as many times as you want. They are the most toxic mammals in the Arctic.”

The new analyses will look not only for all the components of the toxic cocktail of killer whales. In addition, it will measure the amounts of Deca-BDE, a brominated flame retardant found in a multitude of everyday objects and suspected of acting as a neurotoxin that could affect fetal development. Likewise, the vitamin A content will be analyzed, which can indicate if toxins are affecting vital systems, such as hormones. Recent studies show that the concentration of brominated retardants in the environment is doubling every five years.

In addition to the special Arctic conditions (cold and lack of light) that make it even more difficult for toxins to degrade, the general patterns of circulation of pollutants in the air and ocean water (and even those of animal migrations) transport pollutants to the Arctic, a region far from industrial centers. In this way, most of Europe’s pollution ends up in the Arctic, which acts as a sink for toxins.

For Rasmus Hansson, Director of WWF/Norway: “Because of this phenomenon, the Arctic functions as a global indicator, as an early warning system that indicates the health of the planet.”