Killer whale 'most toxic' Arctic mammal

Posted: 12 December 2005

Norwegian killer whales are the most toxic mammals in the Arctic, it was revealed today.This also means that they are likely to be one of the most contaminated groups of animals on the planet, because the Arctic - perceived by most people to be the epitome of pristine environments - is severely polluted by hazardous man-made chemicals.

Previous Arctic research named the polar bear as "most contaminated mammal", but a new study shows that killer whales - or Orcas - have even higher levels of PCBs, pesticides and a brominated flame retardant. So far no other Arctic mammals have been shown to have such high levels.

Surfacing Killer whale, Tysfjord, Nordland, North-Western Norway. © WWF / Ronny Frimann/
Surfacing Killer whale, Tysfjord, Nordland, North-Western Norway. © WWF / Ronny Frimann/
Surfacing Killer whale (Orcinus orca), Tysfjord, Nordland, North-Western Norway.© WWF / Ronny Frimann/
The findings,announced by WWF, underline the need for strong EU legislation to control chemicals. Tomorrow (December 13th) a key meeting of European ministers will decide what form this legislation - called REACH - takes, but pressure from the chemicals industry may lead to REACH becoming so watered-down that it does not protect either human health or the environment - leading to even worse contamination of the seas and the life within. The new killer whale results are based on blubber samples taken from Orcas in Tysfjord, a fjord in arctic Norway. This is the first time the findings of the research, carried out by the Norwegian Polar Institute (NPI), and funded by the Norwegian Research Council, have been revealed.

More resarch Dr Hans Wolkers, a researcher with NPI, said: "Killer whales can be regarded as indicators of the health of our marine environment. The high levels of contaminants are very alarming and clearly show that the arctic seas are not as clean as they should be - which particularly affects animals at the top of the food chain." WWF has now funded Dr Wolkers to carry out research to further monitor the levels of toxic chemicals in killer whales, including another brominated flame retardant called deca-BDE, used in electronic goods and coatings for household products such as carpets. The findings of this research are expected next year. The appearance of a potentially dangerous brominated flame retardant in the killer whales is of particular concern, because - unlike PCBs and the most harmful pesticides - many hazardous brominated flame retardants are not currently banned. Brominated flame retardants can affect mammals' neurological function, behaviour and reproduction. Colin Butfield, leader of WWF-UK's Chemicals and Health Campaign said: "This research re-confirms that the Arctic is now a chemical sink. Chemicals from products that we use in our homes every day are contaminating arctic wildlife. It is tragic that even dangerous chemicals banned many years ago - like DDT and PCBs - are still being found in arctic wildlife and even the fish that we eat in Britain. "The European Council of Ministers must agree to a strong REACH, which sees the replacement of hazardous chemicals with safer alternatives whenever these are available."

Toxic burden

Clare Doole, Head of Press at WWF International> adds:

In addition to testing for all sorts of toxics cocktails found in orcas, future research will look for a particular brominated flame retardant called Deca-BDE, used in plastics, electronic goods and coatings for household products such as carpets and other upholstered fabrics. They will also analyze the blubber samples for vitamin A levels, which can indicate whether the toxins are impacting on vital systems such as hormones.

Recent studies have shown that concentrations of brominated flame retardants are already doubling their concentrations in the environment every five years. Time is of the essence to find out more about these bio-accumulating toxins before it's too late.

"As the migratory pattern of the herring changes, the whales have begun to move offshore into deeper waters," noted Tiu Simila, a marine biologist who has been studying the behaviour of the Tysfjord whales for the past 18 years.. "This means we will soon lose an opportunity to find out more about their behaviour and the impact that contamination is having on their health."

Since the killer whales first came to Tysfjord, they have given us an unprecedented glimpse into their natural world. Unfortunately, our parting gift to them, as they move back to the ocean, is more of a poisoned chalice, a toxic burden whose lethal consequences are not yet known.


  • The Orca (Orcinus orca) is the largest member of the dolphin family. It is found throughout the world's oceans, but tends to prefer the cooler, more productive polar and temperate waters. Like all dolphins, orcas use sophisticated biological sonar, called echolocation and can swim up to 50kph and travel 120-160 kilometres per day. Males can be up to 9.5m long and weigh in excess of 6 tons. Females are smaller, reaching up to 8.5m and weighing about 5 tons.

  • The Stockholm Convention is a global treaty to protect human health and the environment from persistent organic pollutants (POPs); chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of living organisms and are toxic to humans and wildlife. POPs circulate globally and can cause damage wherever they travel. In implementing the Convention, governments will take measures to eliminate or restrict the production and use of the selected POPs.
  • Related links: Toxic chemicals threaten Arctic

    Poisoning the purity of the Arctic