Atlantic White-sided Dolphin, Lagenorhynchus acutus

Atlantic white-sided dolphins are very athletic creatures that actively seek out boats and large whales in order to ride their bow waves. It is often found in the company of other active marine mammals, such as sea lions, Dall's porpoises, and other dolphins. This species lives in groups, or pods, of up to 1000 individuals, although most groups consist of only 10 to 60 individuals. Calves are born in the spring or mid-summer and lactation continues for another 18 months. After this period, young dolphins – of both sexes – leave their mothers. Males likely join small groups of similarly "adolescent" males. These dolphins live for at least 22 years.

Little information is available about the ecology and behaviour of this dolphin, but it is considered abundant and has a range that is very similar to that of the white-beaked dolphin. Both of these mammals inhabit the North Atlantic from Canada to Europe. There has been some interest in starting a subsistence fishery for this species in northern Greenland, but so far only incidental catches from fishing trawlers have occurred.