Photos of marine mammals. There are nearly 130 species of marine mammals, all of which rely on the ocean for their survival. Marine mammals have adaptions to life in the ocean, such as a thick layer of blubber or far, streamlined bodies for swimming, circulatory adjustment abilities to help conserve body temperature, they store extra oxygen in their blood and muscles. Marine mammals are divided into 4 different subgroups, the pinipeds (seals, sea lions, etc), cetaceans (whales, etc), sirenians (manatees, and dugongs) and fissipeds (includes the polar bear).
Marine Mammals are protected by US Law under the Marine Mammal Protection Act of 1972. Many species of marine mammals remain threatened and/or endangered.