Marine Mammals

Marine mammals are mammals whose lives depend substantially on the sea, including whales, dolphins, seals, sea lions, walruses, manatees and sea otters. They breathe air and nurse their young, while using varied body forms and feeding methods to live in marine environments. Some remain in water throughout life, whereas others return to land or ice to rest, breed or give birth. Insulating fat or dense fur helps limit heat loss. Their movements connect coastal habitats, open water and, for some species, polar sea ice.