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Cheaper, faster, and less invasive Casey Lessard Northern News Services Published Monday, November 21, 2011
Of course, all of those polar bears walked away without even noticing the Department of Environment polar bear biologist team's volleys, which were darts that clipped off a small piece of skin for biopsy testing. Typically, Atkinson and his team would use tranquilizer darts to sedate polar bears to do population sampling and tooth extraction, but this year, they used the biopsy technique instead. "This is new in polar bear research," Atkinson said. "It's been used quite extensively (elsewhere) on marine mammals and a number of species, grizzly bears for example. It's the first time we've ever tried biopsy-based population assessment. It would probably be the first time in North America that a comprehensive population assessment was done using genetic mark recapturing on polar bears." The switch to biopsy sampling was in response to Inuit concerns about scientific handling of polar bears in Nunavut. "The GN has made a serious commitment to examine alternative methods, and this is one of those methods, so it's being put into practise," he said. "We will see how Baffin Bay goes, and see whether it will be applicable to other parts of Nunavut." Different needs require different approaches: in areas that are wide open, such as western Hudson Bay and Foxe Basin, aerial surveys are good enough to determine population. However, when biologists want more detail about health and genetics, they need to get physical samples. The aerial survey technique is ineffective in the mountainous terrain of the Baffin Bay area, Atkinson said. That, combined with the concerns over handling, prompted the government to consider the biopsy technique. "The bears don't react to the dart. It doesn't make them jump, fall over or anything," he said. "When you land, you land on top of the dart and the bears are either jogging or walking away from the helicopter. The reaction is minimal. The size of the sample is approximately half-a-centimetre. Relatively speaking, it's quite benign." The biopsy technique is an improvement from the past when bears were tranquilized, said Robbie Kullualik, who helped perform the survey between Qikiqtarjuaq and Clyde River for five days in September. A casual garbage truck driver in Qikiqtarjuaq, Kullualik got the job after the local HTO sought assistance over the local radio. "I called and told them I would like to do it," he said, noting polar bears are his favourite animal. "They picked my name and that day we were looking for polar bears. We saw lots of polar bears. We saw over 150 close to Qikiqtarjuaq." With less handling, the biologists can collect more samples. Because there is no need to sedate and secure the animal, Atkinson's team was able to take samples from 480 bears - from Bylot Island near Pond Inlet to Cape Dyer near Qikiqtarjuaq - compared to the 250 to 300 they would have sampled with physical mark-recapturing. "As biologists, we're always looking for new ways of studying without handling the animal," Atkinson said. "Does it allow us to get a good population assessment done in a relatively short period of time and in a cost-effective manner?" Biopsy mark recapture comes close, although it doesn't give as much detail as the physical mark recapture would. A drawback of both mark recapture techniques is that, unlike an aerial survey, which gives instant results, more surveying is required over several years to get results. Also, DNA testing takes time, so Atkinson's team will spend the winter analyzing the DNA, and then go out next fall to re-sample the Baffin Bay population to determine trends. The last polar bear study took four years from 1993 to 1997. The first results from the current survey will not be available until 2013.
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