Norwegian killer whales most toxic mammals in Arctic
A new WWF-supported report shows that Norwegian killer whales are the most toxic mammals in the Arctic.
© WWF-Canon / William W. Rossiter
© WWF-Canon / William W. Rossiter
12 Dec 2005
Gland, Swtizerland – Initial scientific results show Norwegian killer whales are the most toxic mammals in the Arctic, says WWF, the global conservation organization.
Previous research awarded this dubious honour to the polar bear, but a new study shows that killer whales have even higher levels of PCBs, pesticides and a brominated flame retardant.
The results are based on blubber samples taken from killer whales 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 partly funded by the Norwegian Research Council, have been revealed.
“Killer whales can be regarded as indicators of the health of our marine environment," said Dr Hans Wolkers, a researcher with NPI.
"The high levels of contaminants are very alarming. They clearly show that the arctic seas are not as clean as they should be, which, in particular, affects animals at the top of the food chain.”
Killer whales are found throughout arctic Norway, including Svalbard and the Barents Sea, but congregate in the Tysfjord area to feed on spawning herring during the winter. This offers an excellent opportunity to sample them in an efficient way.
WWF funded Dr Wolkers to carry out new research from this November to further monitor the levels of dangerous contaminants in the 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 killer whales is of particular concern, because – unlike PCBs and the most harmful pesticides – most hazardous brominated flame retardants are not currently banned. Brominated flame retardants can affect the animals' neurological function, behaviour and reproduction.
"This new killer whale research re-confirms that the Arctic is now a toxic sink," said Brettania Walker, a toxics officer with WWF's International Arctic Programme.
"Chemicals in everyday products are contaminating arctic wildlife. The European Council of Ministers, due to vote on REACH on December 13th, must agree to the replacement of all hazardous chemicals with safer alternatives whenever these are available."
"The toxic contamination of killer whales clearly shows the result of an unsustainable use of chemicals internationally," added Helen Bjørnøy, the Norwegian Minister of Environment. "This is one of the greatest global environmental threats. The EU ministers now have the possibility to strengthen the chemicals legislation in Europe, and I urge them to use it. It is imperative that the REACH regulation becomes a tool to stop using the most dangerous chemicals."
• Killer whales are particularly vulnerable to contaminants because they feed at the top of the food chain and therefore accumulate contaminants from the species they prey on. These contaminants accumulate in their blubber and other fat-rich tissues. Killer whales can live up to 40 years so can have very high contaminant levels in their tissues. Toxin levels increase moving up the food chain (a process called biomagnification) and are highest in top predators, such as polar bears.
• Blubber samples were taken from ten male killer whales from Tysfjord, Norway in November 2002. They were later tested for PCB 153, toxaphene, chlordane, DDE, and PBDE 47. They showed higher levels of these chemicals compared to Svalbard polar bears and harbor seals and beluga whales from Svalbard and the Gulf of St. Lawrence, Canada.
• The PBDE (polybrominated diphenyl ethers) class of brominated flame retardants is structurally similar to PCBs and exponential increases of PBDEs have been documented in wildlife and humans in recent years. PBDEs are used in electrical equipment, construction materials, coatings, textiles and polyurethane foam.
• The PBDE brominated flame retardant detected in the Norwegian killer whales sampling was 2,2',4,4'-tetrabromodiphenyl ether, also called PBDE 47. PBDE 47 is often studied due to its persistence and ability to bioaccumulate. Studies in mice have linked neonatal exposure to PBDE 47 to permanent alterations in spontaneous behavior.
• Many pollutants of concern in the Arctic were not produced or ever used in the Arctic. Instead, chemicals from everyday household products and industrial and agricultural chemicals from other areas of the world travel great distances via air and water currents to finally end up in the Arctic. Long, dark winters and cold temperatures inhibit the breakdown of chemicals in the Arctic.
• REACH (Registration, Evaluation and Authorisation of Chemicals) is the draft EU law that should lead to the identification and phasing out of the most harmful chemicals. If it becomes law it will be enforced in all countries in the European Union. REACH will also lead to changes in chemical regulation and production outside the European Union. The current EU chemical regulatory system, similar to others around the world, considers chemicals "safe until proven otherwise".