Oceans and seas

Observed from space, our planet’s surface appears to be dominated by the color blue. This blue color occurs because of the presence of the oceans and seas of the world. These features cover approximately 71% or 361 million square kilometers (139 million square miles) of Earth’s surface with a volume of about 1370 million cubic kilometers (329 million cubic miles). The average depth of these bodies of seawater is about 3.8 kilometers (2.4 miles). Maximum depths can exceed 10 kilometers (6.2 miles) in areas known as ocean trenches. The oceans contain 97% of our planet's available water. The ocean is also home to many forms of life uniquely adapted to survive in this habitat. Humans have degraded the oceans and their life through pollution, overfishing, carbon dioxide acidification and resource exploitation.

  • Indigo hamlet Featured Article Indigo hamlet Indigo hamlet

    The indigo hamlet (scientific name: Hypoplectrus indigo) is a member of the grouper/seabass family (Family Serranidae) that live on coral reefs in the Western Atlantic Ocean... More »

  • Spinner dolphin Featured Article Spinner dolphin Spinner dolphin

    The Spinner dolphin (Stenella longirostris), a marine mammal in the family of oceanic dolphins,  gets its name from the spinning behavior it shows when it leaps out of... More »

  • Ocean acidification troubles Featured Article Ocean acidification troubles Ocean acidification troubles

    The seas in which corals and other calcifying species dwell are turning acidic, their pH slowly dropping as Earth's oceans acidify in response to increased carbon dioxide... More »

  • Marine biodiversity Featured Article Marine biodiversity Marine biodiversity

    Biodiversity is now commonly defined as the variety of life in genes, species and habitats. According to the definition of the Convention on Biological Diversity, biodiversity is... More »

  • Coccolithophores Featured Article Coccolithophores Coccolithophores

      Like any other type of phytoplankton, coccolithophores are one-celled marine plants that live in large numbers throughout the upper layers of the ocean. Unlike any... More »

  • Long-finned pilot whale Featured Article Long-finned pilot whale Long-finned pilot whale

    The long-finned pilot whale (scientific name: Globicephala melas) is one of two species in the genus Globicephala. The pilot whale is so named because when swimming, the groups... More »

  • Seas of the world Featured Article Seas of the world Seas of the world

    A sea is commonly defined to be an extended body of saline water associated with one of the worlds five oceans (Atlantic, Indian, Pacific, Arctic, and Southern oceans). Some seas... More »

Recently Updated
Climate Last Updated on 2014-10-01 10:48:54 Climate is the typical pattern of conditions of the earth’s atmosphere over a given region, as defined by factors such as temperature, air pressure. humidity, precipitation, sunlight, cloudiness, and winds. The World Meteorological Organization defines climate as "the statistical description in terms of the mean and variability of relevant quantities over a period of time," where an appropriate period is typically at least thirty years. Climate can be assessed at different, overlapping geographic regions. For example, Earth is thought to have a climate that is distinct from that of other planets, while different regions of Earth are also thought to have distinct climate types. Climate is often described as the "average" conditions; however, since daily and seasonal variability (including extremes) are critical determinants, using the term... More »
Mangrove ecology Last Updated on 2014-10-01 10:45:20 ​Mangrove ecology is the study of biotic interactions within mangrove swamp ecosystems. These habitats are significant not only for the biodiversity they represent, but also for the protection of coastal erosion, and for the provision of protected nursery areas for marine fauna.   Mangroves worldwide cover an approximate area of 240 000 square kilometers of sheltered coastlines in the tropics and subtropics. Mangroves stabilize coastal intertidal soils pereventing coastal erosion Four of the most common ecotypes include fringe, riverine, basin, and scrub forests. Mangroves are restricted to the intertidal zone. Mangroves in general have a great capacity to recover from major natural disturbances. Mangroves maintain water quality by trapping sediments and taking up excess... More »
Northwestern Hawaiian Islands Marine National Monument Last Updated on 2014-07-23 19:37:23 The Northwestern Hawaiian Islands Marine National Monument is the single largest conservation area under the U.S. flag, and the largest marine conservation area in the world. It encompasses 137,792 square miles of the Pacific Ocean – an area larger than all the country's national parks combined. If they were laid atop the continental United States, the Northwest Hawaiian Islands (NWHI) would cover a distance equal to that between New York City and Omaha, or Boston and the Florida Everglades. The NWHI coral reefs are the foundation of an ecosystem that hosts more than 7,000 species, including marine mammals, fishes, sea turtles, birds, and invertebrates. Many are rare, threatened, or endangered. At least one quarter are endemic, found nowhere else on Earth. Many more remain unidentified or even unknown to science. Many of the islands and shallow water environments are... More »
Pinniped Last Updated on 2014-07-21 17:04:25 Pinnipeds ("finned-feet") are are group of marine mammals, that includes seals, sea lions, and walruses. The word pinniped is sometimes treated as a synonym for "seal" since all pinnipeds except for the the sole species of Walrus are seals (sea lions are eared seals).     Scientific Classification Kingdom: Animalia (Animals) Phylum:--- Chordata Class:------ Mammalia (Mammals) Order:-------- Carnivora (Carnivores) Family:-------- Otariidae (Eared seals) Pinnipeds differ form other marine mammals like whales, dolphins and porpoises in that they do not spend their entire lives in water. Pinnipeds "haul out" onto land and ice to mate, give birth, moult, and rest. Pinnipeds were agressively hunted until the early twentieth century for their skins, oil, meat and, in the case of... More »
Hawaiian Islands Humpback Whale National Marine Sanctuary Last Updated on 2014-07-10 16:22:15 The Hawaiian Islands Humpback Whale National Marine Sanctuary is one of 13 sanctuaries in the National Marine Sanctuary System created under the U.S. Marine Protection, Research and Sanctuaries Act. The sanctuary's goal is to promote comprehensive and coordinated management, research, education and long-term monitoring for the endangered humpback whale and its habitat. The Hawaiian Islands are the world's most isolated island archipelago, born of ancient volcanoes and inhabited by animals and plants derived from ancestors that found their way here over thousands of miles of ocean. According to scientists, the shallow, warm waters surrounding the main Hawaiian Islands constitute one of the world's most important habitats for the endangered humpback whale. Nearly two-thirds of the entire North Pacific population of humpback whales migrates to Hawai`i each winter. Here,... More »