Pollutants blamed for huge increase in hermaphrodite polar bears

Recent studies have shown that 1.2% of Svalbard’s polar bear population now have the reproductive organs of both sexes, but that ten years ago the phenomenon was unknown in this Norwegian territory where the bear’s population equals that of humans.

Researchers from the Norwegian Polar Institute believe that it may be no coincidence that levels of Pychlorinated biphenyls (PCBs) in Svalbard polar bears are up to 20 times higher than Alaskan ones.

Dr Andrew Derocher, a research scientist at the Norwegian Polar Institute, told edie that effects of pollutants such as PCBs on polar bears could be tracked because of the short and simple food chain. Plankton contaminated by the chemicals is eaten by fish, which are subsequently eaten by ringed seals, the staple diet of polar bears. Polar bears are thought to be the animals most visibly affected by PCBs because they primarily consume seal fat, and such pollutants gather in fat tissue. PCBs are known to affect the endocrine system, which may explain conditions such as hermaphroditism taking place among the female bears.

Svalbard is particularly prone to pollution because toxic materials are dumped by the prevailing southerly winds from industrial Europe and also by large Russian rivers carrying pollutants into the Norwegian Sea through the Fram Strait, west of the islands.

Although PCBs are banned in developed countries some nations still use them.“We know that the Russians are still using PCBs in the manufacturing process of products such as submarines,” Derocher said. However, he also pointed out that chlorinated pesticides and polybrominated compounds, which are in widespread use in developed countries, and are not being phased out, could also be as damaging as PCBs in the Arctic.

Derocher also pointed out that the only other polar areas which are as polluted as Svalbard; Frans Josef Land and Novaya Zemlya in the Russian Arctic, both harbour hermaphrodite polar bears, and that after being involved with several thousand polar bears in the Canadian Arctic, he had never seen such a deformity.

“Realistically, I think that pollution will put increasing pressure on the Arctic ecosystem and on polar bears in particular. The situation could be quite dire for them if we don’t change the situation in the next 10 to 20 years,” Derocher said.

He added that as well as hermaphroditism, polar bears and other Arctic creatures are showing signs of immune system depreciation, another side effect of PCB contamination.

Derocher said that his team would begin researching the effects of pollution on the survival of polar bear offspring, which are particularly susceptible because of drinking their mother’s milk, which harbours pollutants such as PCBs.

The researcher also said that his team had also found that PCBs are causing reproductive abnormalities in polar bears, and that together with the ongoing monitoring of the incidence of hermaphrodite bears would also be examined.