Saturday, 24 July 2010

Pacific Ocean

"The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east."

"At 169.2 million square kilometres (63.8 million square miles) in area, this largest division of the World Ocean – and, in turn, the hydrosphere – covers about 46% of the Earth's water surface and about 30% of its total surface.[1] The equator subdivides it into the North Pacific Ocean and South Pacific Ocean, with two exceptions: the Galápagos and Gilbert Islands, while straddling the equator, are deemed wholly within the South Pacific.[2] The Mariana Trench in the western North Pacific is the deepest point in the Pacific and in the world, reaching a depth of 10,911 metres (35,797 ft).[3]"

"The Pacific Ocean was sighted by Europeans early in the 16th century, first by the Spanish explorer Vasco Núñez de Balboa who crossed the Isthmus of Panama in 1513 and named it Mar del Sur (South Sea). Its current name is however derived from the Luso-Latin macaronic Tepre Pacificum, "peaceful sea", bestowed upon it by the Portuguese explorer Ferdinand Magellan[4]."

  1. ^ Pacific Ocean". Britannica Concise. 2006. Chicago: Encyclopædia Britannica, Inc.
  2. ^ a b International Hydrographic Organization (1953). "Limits of Oceans and Seas, 3rd edition". Monte Carlo, Monaco: International Hydrographic Organization. Retrieved 12 June 2010.
  3. ^ "Japan Atlas: Japan Marine Science and Technology Center". Retrieved 2007-07-04.
  4. ^

Published under CC-BY-SA license from Pacific Ocean at Wikipedia.

Blue Whale

"The Blue whale (Balaenoptera musculus) is a marine mammal belonging to the suborder of baleen whales (called Mysticeti).[3] Blue Whales can reach up to 33 metres (108 ft) in length and 180 metric tons (200 short tons)[4] or more in weight. In volume, it is the largest animal existing or known to have existed.[5]"

"Long and slender, the blue whale's body can be various shades of bluish-grey dorsally and somewhat lighter underneath.[6] There are at least three distinct subspecies: B. m. musculus of the North Atlantic and North Pacific, B. m. intermedia of the Southern Ocean and B. m. brevicauda (also known as the pygmy blue whale) found in the Indian Ocean and South Pacific Ocean. B. m. indica, found in the Indian Ocean, may be another subspecies. As with other baleen whales, its diet consists almost exclusively of small crustaceans known as krill.[7]"

"Blue whales were abundant in nearly all the oceans until the beginning of the twentieth century. For over 40 years, they were hunted almost to extinction by whalers until protected by the international community in 1966. A 2002 report estimated there were 5,000 to 12,000 blue whales worldwide[8], located in at least five groups. More recent research into the Pygmy subspecies suggests this may be an underestimate.[9] Before whaling, the largest population was in the Antarctic, numbering approximately 239,000 (range 202,000 to 311,000).[10] There remain only much smaller (around 2,000) concentrations in each of the North-East Pacific, Antarctic, and Indian Ocean groups. There are two more groups in the North Atlantic, and at least two in the Southern Hemisphere."

  1. ^ a b c Mead, James G.; Brownell, Robert L., Jr. (16 November 2005). "Order Cetacea (pp. 723-743)". in Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). pp. 725. ISBN 978-0-8018-8221-0.
  2. ^ Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. (2008). Balaenoptera musculus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 7 October 2008.
  3. ^ a b c d e f "American Cetacean Society Fact Sheet - Blue Whales". Retrieved 20 June 2007.
  4. ^ "Animal Records". Smithsonian National Zoological Park. Retrieved 2007-05-29.
  5. ^ "What is the biggest animal ever to exist on Earth?". How Stuff Works. Retrieved 2007-05-29.
  6. ^ FI - Species fact sheets. Fisheries and Aquaculture Department, Food and Agriculture Organization.
  7. ^ a b c Jason de Koning and Geoff Wild (1997). "Contaminant analysis of organochlorines in blubber biopsies from blue whales in the St Lawrence". Trent University. Retrieved 2007-06-29.
  8. ^ a b c d "Assessment and Update Status Report on the Blue Whale Balaenoptera musculus" (PDF). Committee on the Status of Endangered Wildlife in Canada. 2002. Retrieved 2007-04-19.
  9. ^ a b Alex Kirby (2003-06-19). "Science seeks clues to pygmy whale". BBC News. Retrieved April 21, 2006.
  10. ^ a b c T.A. Branch, K. Matsuoka and T. Miyashita (2004). "Evidence for increases in Antarctic blue whales based on Bayesian modelling". Marine Mammal Science 20: 726–754. doi:10.1111/j.1748-7692.2004.tb01190.x.

Published under CC-BY-SA license from Blue Whale at Wikipedia.

Humpback Whale

The humpback whale (Megaptera novaeangliae) is a baleen whale. One of the larger rorqual species, adults range in length from 12–16 metres (39–52 ft) and weigh approximately 36,000 kilograms (79,000 lb). The humpback has a distinctive body shape, with unusually long pectoral fins and a knobbly head. It is an acrobatic animal, often breaching and slapping the water. Males produce a complex whale song, which lasts for 10 to 20 minutes and is repeated for hours at a time. The purpose of the song is not yet clear, although it appears to have a role in mating.

Found in oceans and seas around the world, humpback whales typically migrate up to 25,000 kilometres each year. Humpbacks feed only in summer, in polar waters, and migrate to tropical or sub-tropical waters to breed and give birth in the winter. During the winter, humpbacks fast and live off their fat reserves. The species' diet consists mostly of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net feeding technique.

Like other large
whales, the humpback was and is a target for the whaling industry. Due to over-hunting, its population fell by an estimated 90% before a whaling moratorium was introduced in 1966. Stocks have since partially recovered; however, entanglement in fishing gear, collisions with ships, and noise pollution also remain concerns. There are at least 80,000 humpback whales worldwide. Once hunted to the brink of extinction, humpbacks are now sought by whale-watchers, particularly off parts of Australia, Canada, and the United States.

Published under CC-BY-SA license from Humpback Whale at Wikipedia.

Sperm Whale

"The sperm whale, Physeter macrocephalus, is a marine mammal species, order Cetacea, a toothed whale (odontocete) having the largest brain of any animal. The name comes from the milky-white waxy substance, spermaceti, found in the animal's head, due to its resemblance to semen. The sperm whale is the only member of genus Physeter. The synonym Physeter catodon refers to the same species. It is one of three extant species in the sperm whale superfamily, along with the pygmy sperm whale and dwarf sperm whale."

"A bull can grow up to 20.5 metres (67 ft) long. It is the largest living toothed animal. The head can take up to one-third of the animal's length. It has a cosmopolitan distribution across the oceans. The species feeds on squid and fish, diving as deep as 3 kilometres (9,800 ft), which makes it the deepest diving mammal. Its diet includes giant squid and colossal squid. The sperm whale's clicking vocalization is the loudest sound produced by any animal, but its functions are uncertain. These whales live in groups called pods. Pods of females and their young live separately from older males. The females cooperate to protect and nurse their young. Females give birth every three to six years, and care for the calves for more than a decade."

"Historically, the sperm whale was also known as the common cachalot; "cachalot" is derived from an archaic French word for "tooth". Over most of the period from the early 18th century until the late 20th century, the sperm whale was hunted to obtain spermaceti and other products, such as sperm oil and ambergris. Spermaceti found many important uses, such as candles, soap, cosmetics and machine oil. Due to its size, the sperm whale could sometimes defend itself effectively against whalers. In the most famous example, a sperm whale attacked and sank the American whaleship Essex in 1820. As a result of whaling, the sperm whale is currently listed as vulnerable by the IUCN. The sperm whale has few natural predators, since few are strong enough to successfully attack a healthy adult; orcas attack pods and kill calves. The sperm whale can live for more than 70 years."

Published under CC-BY-SA license from Sperm Whale at Wikipedia.

Toothed Whale

The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans, including sperm whales, beaked whales, orca[1], dolphins, and others. As the name suggests, the suborder is characterized by the presence of teeth rather than the baleen of other whales.


Published under
CC-BY-SA license from Toothed Whale at Wikipedia.


"Porpoises (also called mereswine) are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" (pronounced /ˈpɔrpəs/) has been used to refer to any small dolphin, especially by sailors and fishermen. The most obvious visible difference between the two groups is that porpoises have flattened, spade-shaped teeth distinct from the conical teeth of dolphins, and shorter beaks."

"The name derives from French pourpois, originally from Medieval Latin porcopiscus (porcus pig + piscus fish)."

"Porpoises, divided into six species, live in all oceans, mostly near the shore. Freshwater populations of the Finless Porpoise also exist. Probably the best known species is the Harbour Porpoise, which can be found across the Northern Hemisphere. Like all toothed whales, porpoises are predators, using sounds (echolocation in sonar form) to locate prey and to coordinate with others. They hunt fish, squid, and crustaceans."

Published under CC-BY-SA license from Porpoise at Wikipedia.


"Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in seventeen genera. They vary in size from 1.2 m (4 ft) and 40 kg (90 lb) (Maui's Dolphin), up to 9.5 m (30 ft) and 10 tonnes (9.8 LT; 11 ST) (the Orca or Killer Whale). They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating fish and squid. The family Delphinidae is the largest in the Cetacean order, and relatively recent: dolphins evolved about ten million years ago, during the Miocene. Dolphins are among the most intelligent animals and their often friendly appearance and seemingly playful attitude have made them popular in human culture."

Published under CC-BY-SA license from Dolphin at Wikipedia.