aboriginal whaling adipose tissue ambergris baleen blood vessel buoyancy dolphin drive hunting fat fur globster history of whaling hypodermis international whaling commission inuit lipid mammal metabolism muktuk pinniped polychlorinated biphenyl selenium spermaceti thermal insulation thermoregulation try pot uummannaq vitamin e whale oil whaling whaling in america whaling in australia whaling in iceland whaling in japan whaling in norway whaling in western australia whaling in the faroe islands whaling in the netherlands