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
Strap-toothed whale individual was seen breaching between the South Orkney Islands and South Georgia. Strap-toothed whales' diet consists primarily of squid, although research has suggested that a small portion of their diet may also consist of fish or crustaceans. Adult males have a gape half the size of females and juveniles, limiting their squid to those weighing and less. Nothing is known about social organization of this species. This species has never been hunted or entangled in fishing gear. It is believed to be in a rather safe position compared with other mesoplodonts. Layard's beaked whale is included in the Memorandum of