Marine biology gannets, and auks. Although they spend most of their lives in the ocean, species such as gulls can often be found thousands of miles inland. There are five main types of marine mammals, namely cetaceans (toothed whales and baleen whales); sirenians such as manatees; pinnipeds including seals and the walrus; sea otters; and the polar bear. All are air-breathing, and while some such as the sperm whale can dive for prolonged periods, all must return to the surface to breathe. Marine habitats can be divided into coastal and open ocean habitats. Coastal habitats are found in the area that extends
Captive killer whales they are successful, and withholding it when they are not. Secondary reinforcement—things not essential to life, such as play time, tactile rewards and fun games—can also be used as rewards. The practice of keeping killer whales in captivity is controversial, and organizations such as World Animal Protection and the Whale and Dolphin Conservation campaign against the captivity of killer whales. Orcas in captivity may develop physical pathologies, such as the dorsal fin collapse seen in 80–90% of captive males. The captive environment bears little resemblance to their wild habitat, and the social groups that the killer whales are put into