Reply To: Global warming threatens biodiversity

#4381
imported_Martin
Participant

Polar Bears International website has good info countering claims that polar bear populations are increasing so no worries for them with global warming.

Quote:
Dr. Derocher is a polar bear scientist with the University of Edmonton in Canada. He also serves on PBI’s Scientific Advisory Council.

The various presentations of biased reporting ignore, or are ignorant of, the different reasons for changes in populations. If I thought that there were more bears now than 50 years ago and a reasonable basis to assume this would not change, then no worries. This is not the case.

The bottom line here is that it is an apples and oranges issue. The early estimates of polar bear abundance are a guess. There is no data at all for the 1950-60s. Nothing but guesses. We are sure the populations were being negatively affected by excess harvest (e.g., aircraft hunting, ship hunting,self-killing guns, traps, and no harvest limits). The harvest levels were huge and growing. The resulting low numbers of bears were due only to excess harvest but, again, it was simply a guess as to the number of bears.

After the signing of the International Agreement on Polar Bears in the 1970s, harvests were controlled and the numbers increased.

There is, however, very strong evidence for a decline in Western Hudson Bay and the Southern Beaufort Sea based on quantitative studies. More recently, scientists working in the Southern Hudson Bay have reported a major decline in the condition of polar bears. A decline in condition was the precursor to the population decline in Western Hudson Bay. There is clear suggestion of a population decline due to over-harvest in Baffin Bay, Kane Basin and possibly Norwegian Bay.

Look at the messengers: lobby groups for big business say there is no problem.

Comparing declines caused by harvest followed by recovery from harvest controls to declines from loss of habitat and climate warming are apples and oranges. Ignorant people write ignorant things.

Ask the Experts: Are Polar Bear Populations Increasing?