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Endangered Sharks
__NOTOC__ Threatened sharks are those vulnerable to endangerment (extinction) in the near future. The International Union for Conservation of Nature ( IUCN) is the world's oldest global environmental organization. It evaluates threatened species, and treats threatened species not as a single category, but as a group of three categories, depending on the degree to which they are threatened: :: Vulnerable species :: Endangered species :: Critically endangered species The term ''threatened'' strictly refers to these three categories (critically endangered, endangered and vulnerable), while ''vulnerable'' is used to refer to the least at risk of these categories. The terms can be used somewhat interchangeably, as all ''vulnerable'' species are threatened, all ''endangered'' species are vulnerable and threatened, and all ''critically endangered'' species are endangered, vulnerable and threatened. Threatened species are also referred to as a red-listed species, as they are listed i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whale Shark Georgia Aquarium
Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and porpoises. Dolphins and porpoises may be considered whales from a formal, cladistic perspective. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates. Their closest non-cetacean living relatives are the hippopotamuses, from which they and other cetaceans diverged about 54 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have had their last common ancestor around 34 million years ago. Mysticetes include four extant (living) families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy right whale), and Eschrichtiidae (the grey whale). Odontocetes include the Monodontidae (belugas and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Pollution
Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although marine transportation significantly contributes as well. Since most inputs come from land, either via the rivers, sewage or the atmosphere, it means that continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor by carrying off iron, carbonic acid, nitrogen, silicon, sulfur, pesticides or dust particles into the ocean. The pollution often comes from nonpoint sources such as agricultural runoff, wind-blown debris, and dust. These nonpoint sources are largely due to runoff that enters the ocean through rivers, but wind-blown debris and dust can also play a role, as these pollutants can settle into waterways and oceans. Pathways of pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great White Shark
The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large Lamniformes, mackerel shark which can be found in the coastal surface waters of all the major oceans. It is notable for its size, with larger female individuals growing to in length and in weight at maturity. However, most are smaller; males measure , and females measure on average. According to a 2014 study, the lifespan of great white sharks is estimated to be as long as 70 years or more, well above previous estimates, making it one of the longest lived Chondrichthyes, cartilaginous fishes currently known. According to the same study, male great white sharks take 26 years to reach sexual maturity, while the females take 33 years to be ready to produce offspring. Great white sharks can swim at speeds of 25 km/h (16 mph) for short bursts and to depths of . The great white shark is an apex predator, as it has no known natura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porbeagle
The porbeagle (''Lamna nasus'') is a species of mackerel shark in the family Lamnidae, distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere. In the North Pacific, its ecological equivalent is the closely related salmon shark (''L. ditropis''). It typically reaches in length and a weight of ; North Atlantic sharks grow larger than Southern Hemisphere sharks and differ in coloration and aspects of life history. Gray above and white below, the porbeagle has a very stout midsection that tapers towards the long, pointed snout and the narrow base of the tail. It has large pectoral and first dorsal fins, tiny pelvic, second dorsal, and anal fins, and a crescent-shaped caudal fin. The most distinctive features of this species are its three-cusped teeth, the white blotch at the aft base of its first dorsal fin, and the two pairs of lateral keels on its tail. The porbeagle is an opportunistic hunter that preys mainly on bony fis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dogfish Shark
Squalidae, more commonly known as dogfish, dog sharks, or spiny dogfish, are one of several families of sharks categorized under Squaliformes, making it the second largest order of sharks, numbering 119 species across 7 families. Having earned their name after a group of fishermen reportedly observed the species chasing down smaller fish in dog-like packs, dogfish have slender, streamlined bodies, usually more compact in comparison to other species, and a pointed snout. Dogfish likewise have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. As the species reaches adulthood, males usually measure a maximum of 39 inches (990 mm), while females typically measure 49 inches (1,200 mm) long. The species therefore exhibits female-dominant sexual dimorphism. Dogfish sharks have slate-gray or gray-brown skin with white dots that becomes paler (almost white) around the belly region. These sharks are characterized by teeth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceanic Whitetip Shark
The oceanic whitetip shark (''Carcharhinus longimanus''), also known as shipwreck shark, Brown Milbert's sand bar shark, brown shark, lesser white shark, nigano shark, oceanic white-tipped whaler, and silvertip shark, is a large pelagic requiem shark inhabiting tropical and warm temperate seas. Its stocky body is most notable for its long, white-tipped, rounded fins. Though slow-moving, it is opportunistic and aggressive, and is reputed to be dangerous to shipwreck survivors. Recent studies show steeply declining populations because its large fins are highly valued as the chief ingredient of shark fin soup, and as with other shark species, the whitetip faces mounting fishing pressure throughout its range. Taxonomy The oceanic whitetip shark, or lesser white shark, was described in 1831 by naturalist René-Primevère Lesson, who named the shark ''Carcharhinus maou''. It was next described by Cuban Felipe Poey in 1861 as ''Squalus longimanus''. The name ''Pterolamiops longiman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammerhead Shark
The hammerhead sharks are a group of sharks that form the family Sphyrnidae, so named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a "hammer" shape called a cephalofoil. Most hammerhead species are placed in the genus ''Sphyrna'', while the winghead shark is placed in its own genus, '' Eusphyra''. Many different, but not necessarily mutually exclusive, functions have been postulated for the cephalofoil, including sensory reception, manoeuvering, and prey manipulation. The cephalofoil gives the shark superior binocular vision and depth perception. Hammerheads are found worldwide in warmer waters along coastlines and continental shelves. Unlike most sharks, some hammerhead species usually swim in schools during the day, becoming solitary hunters at night. Description The known species range from in length and weigh from . One specimen caught off the Florida coast in 1906 weighed over . They are usually light gray and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of international trade. It was drafted as a result of a resolution adopted in 1963 at a meeting of members of the International Union for Conservation of Nature (IUCN). The convention was opened for signature in 1973 and CITES entered into force on 1 July 1975. Its aim is to ensure that international trade (import/export) in specimens of animals and plants included under CITES, does not threaten the survival of the species in the wild. This is achieved via a system of permits and certificates. CITES affords varying degrees of protection to more than 38,000 species. , Secretary-General of CITES is Ivonne Higuero. Background CITES is one of the largest and oldest conservation and sustainable use agreements in existence. There are three working langu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Guardian
''The Guardian'' is a British daily newspaper. It was founded in 1821 as ''The Manchester Guardian'', and changed its name in 1959. Along with its sister papers ''The Observer'' and ''The Guardian Weekly'', ''The Guardian'' is part of the Guardian Media Group, owned by the Scott Trust Limited, Scott Trust. The trust was created in 1936 to "secure the financial and editorial independence of ''The Guardian'' in perpetuity and to safeguard the journalistic freedom and liberal values of ''The Guardian'' free from commercial or political interference". The trust was converted into a limited company in 2008, with a constitution written so as to maintain for ''The Guardian'' the same protections as were built into the structure of the Scott Trust by its creators. Profits are reinvested in journalism rather than distributed to owners or shareholders. It is considered a newspaper of record in the UK. The editor-in-chief Katharine Viner succeeded Alan Rusbridger in 2015. Since 2018, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagic
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change. Marine life is affected by bathymetry (underwater topography) such as the seafloor, shoreline, or a submarine seamount, as well as by proximity to the boundary between the ocean and the atmosphere at the ocean surface, which brings light for photosynthesis, predation from above, and wind stirring up waves and setting currents in motion. The pelagic zone refers to the open, free waters away from the shore, where marine life can swim freely in any direction unhindered by topographical constraints. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharkwater
''Sharkwater'' is a 2006 Canadian documentary film written and directed by Rob Stewart. Helping to protect sharks, changing government policy, and inspiring the creation of shark conservation groups, ''Sharkwater'' is considered one of conservation's success stories, resulting in shark finning being banned in over 90 countries. In the film, Stewart documents current attitudes about sharks, and how shark-hunting industries are driving them to extinction. ''Sharkwater'' explores the densest shark hunting populations in the world, exposing the exploitation and corruption of the shark-hunting industry in the marine reserves of Cocos Island, Costa Rica and the Galapagos Islands, Ecuador. Stewart travels with Paul Watson and his Sea Shepherd Conservation Society ship as they confront shark poachers in Guatemala and Costa Rica. Among the group's experiences are boat confrontations, poachers, police, corrupt court systems, and eventually murder charges. Also, Stewart states how the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shark Finning
Shark finning is the act of removing fins from sharks and discarding the rest of the shark back into the ocean. This act is prohibited in many countries. The sharks are often still alive when discarded, but without their fins.Spiegel, J. (2000"Even Jaws deserves to keep his fins: outlawing shark finning throughout global waters" ''Boston College International and Comparative Law Review'', 24 (2): 409–438. Unable to swim effectively, they sink to the bottom of the ocean and die of suffocation or are eaten by other predators. Shark finning at sea enables fishing vessels to increase profitability and increase the number of sharks harvested, as they must only store and transport the fins, by far the most profitable part of the shark; the shark meat is bulky to transport. Many countries have banned this practice and require the whole shark to be brought back to port before removing the fins. Shark finning increased since 1997 largely due to the increasing demand for shark fins for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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