White giant endangered

PHOTO: GV-PRESS

The polar bear is the world's largest land-based predator. It inhabits the area around the North Pole known as the Arctic. In Norway, there are polar bears on Svalbard, a group of islands also known as Spitsbergen. Polar bears have come close to extermination several times because of hunting. These days, the stock consists of roughly 25 000 animals, and polar bears are well protected by strict laws and regulations.

However, polar bears are now facing another threat. Global warming is shrinking the polar bear's natural habitat. This burly fellow is happiest out on the sea ice, which he uses as a base for hunting seal and other animals. If global temperatures were to rise, the ice could melt. Thus, the bears' habitat will shrink further.

Threatened by environmental toxins

The polar bear has double fur and a thick layer of blubber which keeps it warm even in sub-zero temperatures. We humans do not have the same qualities, so we wear clothes to keep us warm. Fleece jackets are great for that, for example. Believe it or not, though, that very same fleece jacket may actually pose a threat to the polar bear!

Fleece jackets are made entirely of recycled plastic bottles. The jackets are light and warm, but the fabric is also extremely flammable. That means it can catch fire very easily. To deal with the problem, those who manufacture fleece use a special additive to make the fleece more fire resistant. Such fire retardant fabrics probably save lives every year. However, they are also environmental toxins. Environmental toxins are bad for polar bears which are affected by them through the food chain.

At the top of the food chain

The polar bear is at the top or apex of the food chain. This means that polar bears eat their prey, but that no other animals eat polar bears. Polar bears eat a lot of seals which, in turn, eat fish. Those fish eat smaller fish or other prey they capture in the ocean. All these animals absorb environmental toxins made and released by man.

Dinner with a twist

These toxins are not dangerous in small amounts, but they tend to be stored in organisms and thus to build up over time. This is especially the case in animals which have a lot of fat, e.g. seals and fish in the Arctic - and polar bears. Environmental toxins are, in fact, fat soluble, meaning they are stored in the fat cells of the body. When polar bears eat seals, they ingest large quantities of environmental toxins that have been building up in the seals over a long period of time.

PHOTO: MASTERFILE/ SCANPIX

Scientific study

Now a group of Norwegian scientists is going to investigate how polar bears react to climate change, and what kind of problems environmental toxins cause for polar bears. The scientists are going to tag the polar bears with satellite transmitters, so they know where the bears are located at any given time. This will allow them to track the bears' movements to see how they react to changes in climate, navigation and hunting patterns. Researchers are also curious about how the toxins affect polar bears. For example, they are going to study whether the toxins hurt the bears' skeletal system by comparing them with polar bear skulls from museums.

Banned toxins

Most of the environmental toxins that can hurt polar bears are banned today. However, since they are stored in the animals' cells, it takes a long time for them to get out of the food chain. Meanwhile, you may want to consider what kind of garments you wear to keep warm?

Translated by Linda Sivesind

*Published in 'Polar Research', supplement to 'Nysgjerrigper' no. 3-07*