World Ocean that covers and encircles most of Earth. If viewed from the southern pole of Earth, the Atlantic, Indian, and Pacific Oceans can be seen as lobes extending northward from the Southern Ocean. Farther north, the Atlantic opens into the Arctic Ocean, which is connected to the Pacific by the Bering Strait, forming a continuous expanse of water. Plate tectonics, post-glacial rebound, and sea level rise continually change the coastline and structure of the world ocean. World Ocean The World Ocean or Global Ocean (colloquially the sea or the ocean) is the interconnected system of Earth's oceanic waters, and comprises the
Southern Ocean four toothed whales. The largest of these, the blue whale ("Balaenoptera musculus"), grows to long weighing 84 tonnes. Many of these species are migratory, and travel to tropical waters during the Antarctic winter. Five species of krill, small free-swimming crustaceans, have been found in the Southern Ocean. The Antarctic krill ("Euphausia superba") is one of the most abundant animal species on earth, with a biomass of around 500 million tonnes. Each individual is long and weighs over . The swarms that form can stretch for kilometres, with up to 30,000 individuals per , turning the water red. Swarms usually remain