FILE - In this Thursday, July 10, 2008 file photo, a polar bear walks along the ice flow in Baffin Bay above the Arctic circle as seen from the Canadian Coast Guard icebreaker Louis S. St-Laurent. As of 2017, there have been over 400 recorded transits along the Northwest Passage, mostly by Canadian icebreakers and small adventure yachts. (Jonathan Hayward/The Canadian Press via AP)