According to the analysis of the migration patterns of the bowhead whale ( balaena mysticetus ), the Northwest Passage was blocked to such an extent for the past roughly 3000 years that bowhead whales were not able to pass through it.
Global warming has, however, opened the Northwest Passage during the last few weeks.
This map from the National Snow and Ice Center (NSIC), USA from 9 Sep 2007 shows the present region covered by ice, and the average (median) limit of ice in September during 1979-2000 as a pink (ma…
