MOSAIC: Polar bears in peril
By Samina Iqbal
THEORETICALLY a protected species, the polar bear has in practice been exposed to an increasing number of man-made perils, leading researchers to worry that it could be completely extinct in just a matter of decades.
“There’s a big risk of losing the polar bear altogether,” said Kit Kovacs, a Canadian who heads up bio-diversity research at the Norwegian Polar Institute.
While measures are being taken to protect the bears, new threats keep popping up, negating the work that has been done.
Even before the bans on dangerous substances like PCBs (polychlorinated biphenyls) and DDT (dichlorodiphenyltrichloroethane) really start paying off, a flurry of other dangerous substances like mercury and brominated flame retardants have begun posing a significant threat to the king of the ice.
To the researchers’ astonishment, traces of flame retardants — used in abundance in the electronics, textile and automobile industries — have recently been found for the first time in polar bears in the Norwegian archipelago of Svalbard, a mere 1,000 kilometres (620 miles) from the North Pole. These massive mammals are common in the archipelago, home to some 2,500 of a total 25,000 Arctic polar bears.
The source of the toxins and environmental waste is basically in the south, in the industrial zones like North America, Russia and Europe. The substances tend to evaporate and to settle in the Arctic. While the direct effects of these substances remain unclear, researchers suspect that they at the very least seriously damage the bears’ immune system as well as their ability to reproduce.
Over recent years, for instance, a number of “pseudo-hermophrodite” polar bears — females with such protruding sexual organs that they resemble penises — have begun appearing.
The substances “get into the food chain, first in the algae. The algae get eaten by the small fish, the small fish get eaten by the bigger fish, the big fish get eaten by the seals and the seals get eaten by the bears,” said a local Svalbard government representative in charge of environmental issues.
Topping the food-chain, polar bears store nutrients — and poisons — consumed by their prey in their fat as they prepare for hibernation. When the females metabolize the fat to feed the cubs, they spread the compounds in their body and in their milk. Cubs are getting heavy doses while they are at the most vulnerable stage of their lives.
The greatest danger, however, comes from another human-related environmental shift: global warming, which is rapidly shrinking the ice masses that make up the polar bears’ vital hunting grounds. According to the most widely accepted projections, the Arctic icecap will have completely disappeared — during the summer at least — by 2080.
That could be disastrous for the between 80 and 90 per cent of polar bears who spend their summers on the ice hunting seals, which make up 95 per cent of their food intake. The receding ice will probably, eventually drive the polar bears onto land, according to Kovac, who warns that they then may mingle with brown bears.
“But that would be the end of the polar bear as such. It’s definitely a species at high risk and mating would then be the last of their worries anyway,” she said.
As the ice disappears, the bears will be forced to swim longer distances to get to new hunting ground, something that will be difficult for cubs, researchers say. The effort of crossing larger bodies of water is also expected to detract from the adult bears’ sex drive and thereby their ability to reproduce.
Kovacs warned that these kings of the ice could soon be delegated to museum wings dedicated to extinct species.
Stiff fingers
By Dr Fatema Jawad
Carpal Tunnel Syndrome is a tightening of the tunnel compartments at the wrist through which the nerves traverse to the palm. This tightening causes pain and stiffness of the fingers and hand. Local steroid injection and surgical decompression both are accepted treatments for carpal tunnel syndrome, states a recent issue of the journal, Arthritis Rheumatologia. In a study conducted in Spain, on 101 patients, some with both wrists involved, researchers randomized 163 wrists to receive either surgery or local corticosteroid injection. Most injected patients received two injections, two weeks apart. The mean duration of symptoms prior to enrolment was 32 weeks and all patients had had unsatisfactory responses to splinting and pain killers as nonsteroidal anti-inflammatory drugs.
Patients were asked to rate their responses to treatment at three, six, and 12 months. They used a scoring method to record for improvement in daytime pain, numbness in fingers at night and overall functional impairment of the hand. At three months, injected wrists had improved more than surgically treated wrists. At six months, improvement was almost identical in the two groups. At 12 months, no significant differences were noted between the two groups on most measures, although a few trends favoured surgery. The results suggest better symptom relief with local steroid injection during the first few months, but this advantage gradually disappears by six months. It would be helpful to know how these patients fare during several additional years of follow-up. More prolonged monitoring is recommended to get a final answer.
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