Ocean nomads: Distribution and movements of sperm whales in the North Pacific shown by whaling data and Discovery marks

• DOI: 10.1111/j.1748-7692.2012.00601.x
• Publication Date: 2012-12-07T12:19:42Z
• Authors: Sally A. Mizroch; Dale W. Rice
• Keywords: Whaling; Sperm whale; Baleen

Abstract We investigated the distribution and movements of sperm whales ( Physeter macrocephalus ) in North Pacific by analyzing whaling data movement marked with Discovery marks. Prior studies suggested that there were discrete “stocks” whales, assuming intervals between historical areas concentration indicated subpopulation boundaries. Our analyses clearly refute this assumption: marking suggest no obvious divisions separate demes or stocks within Pacific. Sperm appear to be nomadic show widespread concentration, documented over 5,000 km, time spans recovery 20 yr, ranges cover many thousand km 2 . Males range more widely than females. likely travel response geographical temporal variations abundance medium‐ large‐sized pelagic squids, their primary prey. demonstrate males females concentrated seasonally Subtropical Frontal Zone ca 28ºN–34ºN) Subarctic 40ºN–43ºN), also near Aleutian Islands along Bering Sea shelf edge. It appears targeted whalers across ocean basin.