The right whales have been driven nearly to extinction as the species preferred by commercial whalers and have been hunted in spite of international bans.  There are perhaps several hundred in the western Pacific, and perhaps only a handful in the eastern Pacific.  Between 1960 and 1996, only a few solitary animals were sighted; in 1996, a group of four was found in the Bering Sea.

These animals are among the largest mammals and can weigh as much as 100 tons at maturity.  They can live 70 years or longer. The North Atlantic right whale differs in skin color from the North Pacific right whale and the cold waters of the Arctic Circle are a natural impediment to the mingling of these two groups.

Links:
Mammal Species of the World