>In summer, cruise ships, charter boats, and commercial fishing vessels bring thousands of visitors to Whittier’s harbor on the west side of Prince William Sound.
It seems the tourists mostly disembark and take the train to Anchorage[1]. Though I suppose out of 700000 that visit every year even if 5% make purchases it might sustain the population along with the grant they get from the Alaska government.
[1]http://reedyoung.com/project/whittier-alaska/r-young-whittie...