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Marine Mammals
Marine mammals are aquatic mammals that rely on the ocean and other marine ecosystems for their existence. They include animals such as seals, whales, manatees, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival. Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Seals and sea-lions are semiaquatic; they spend the majority of their time in the water but need to return to land for important activities such as mating, breeding and molting. In contrast, both otters and the polar bear are much less adapted to aquatic living. The diets of marine mammals vary considerably as well; some eat zooplankton, others eat fish, squid, shellfish, or sea-grass, and a few eat other mammals. While the number of marine mammals is small compared to those found on land, their roles in various ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrurga Leptonyx Edit1
The leopard seal (''Hydrurga leptonyx''), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). Its only natural predator is the orca. It feeds on a wide range of prey including cephalopods, other pinnipeds, krill, fish, and birds, particularly penguins. It is the only species in the genus ''Hydrurga''. Its closest relatives are the Ross seal, the crabeater seal and the Weddell seal, which together are known as the tribe of Lobodontini seals. The name ''hydrurga'' means "water worker" and ''leptonyx'' is the Greek for "thin-clawed". Taxonomy French zoologist Henri Marie Ducrotay de Blainville described the leopard seal in 1820. Description The leopard seal has a distinctively long and muscular body shape when compared to other seals, but it is perhaps best known for its massive jaws, which allow it to be one of the top predators in its environment. The front teeth are sharp like those of other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California Sea Lion
The California sea lion (''Zalophus californianus'') is a coastal eared seal native to western North America. It is one of six species of sea lions. Its natural habitat ranges from southeast Alaska to central Mexico, including the Gulf of California. California sea lions are sexually dimorphic; males are larger than females, and have a thicker neck, and a protruding sagittal crest. They mainly haul-out on sandy or rocky beaches, but they also frequent manmade environments such as marinas and wharves. California sea lions feed on a number of species of fish and squid, and are preyed on by orcas and great white sharks. California sea lions have a polygynous breeding pattern. From May to August, males establish territories and try to attract females with which to mate. Females are free to move in between territories, and are not coerced by males. Mothers nurse their pups in between foraging trips. California sea lions communicate with numerous vocalizations, notably with bar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinniped
Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 34 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora; their closest living relatives are musteloids (weasels, raccoons, skunks, and red pandas), having diverged about 50 million years ago. Seals range in size from the and Baikal seal to the and southern elephant seal male, which is also the largest member of the order Carnivora. Several species exh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aboriginal Whaling
Indigenous whaling is the hunting of whales by indigenous peoples recognised by either IWC (International Whaling Commission) or the hunting is considered as part of indigenous activity by the country. It is permitted under international regulation, but in some countries remains a contentious issue. (The hunting of smaller cetaceans is covered at Dolphin drive hunting.) It is usually considered part of the subsistence economy. In some places whaling has been superseded by whale watching instead. This article deals with communities that continue to hunt; details about communities that have ended the practice may be found at History of whaling. International regulation Under the terms of the 1986 moratorium, the International Whaling Commission allows the activity to be carried out by aboriginal groups if it occurs on a subsistence basis, similar to subsistence fishing. This Aboriginal Subsistence Whaling is restricted to native peoples and others working on their behalf, as d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Degradation
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby reducing biodiversity and species abundance. Habitat destruction is the leading cause of biodiversity loss. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as they are major threats to the survival of endangered species. Activities such as harvesting natural resources, industrial production and urbanization are human contributions to habitat destruction. Pressure from agriculture is the principal human cause. Some others include mining, logging, trawling, and urban sprawl. Habitat destruction is currently considered the primary cause of species extinction worldwide. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Elephant Seal
The northern elephant seal (''Mirounga angustirostris'') is one of two species of elephant seal (the other is the southern elephant seal). It is a member of the family (biology), family Phocidae (true seal (mammal), seals). Elephant seals derive their name from their great size and from the male's large proboscis, which is used in making extraordinarily loud roaring noises, especially during the mating competition. Sexual dimorphism in size is great. Correspondingly, the mating system is highly polygynous; a successful male is able to impregnate up to 50 females in one season. Description The huge male northern elephant seal typically weighs and measures , although some males can weigh up to . Females are much smaller and can range from in weight, or roughly a third of the male's bulk, and measure from . The bull southern elephant seals are, on average, larger than those in the northern species, but the females in both are around the same size, indicating the even higher level ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Atlantic Right Whale
The North Atlantic right whale (''Eubalaena glacialis'') is a baleen whale, one of three right whale species belonging to the genus ''Eubalaena'', all of which were formerly classified as a single species. Because of their docile nature, their slow surface-skimming feeding behaviors, their tendencies to stay close to the coast, and their high blubber content (which makes them float when they are killed, and which produced high yields of whale oil), right whales were once a preferred target for whalers. At present, they are among the most endangered whales in the world, and they are protected under the U.S. Endangered Species Act and Marine Mammal Protection Act and Canada's Species at Risk Act. There are fewer than 370 individuals in existence in the western North Atlantic Ocean—they migrate between feeding grounds in the Labrador Sea and their winter calving areas off Georgia and Florida, an ocean area with heavy shipping traffic. In the eastern North Atlantic, on the other ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species (freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as "rough fish" (mainly US) and " coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humpback Whale Underwater Shot
Humpback may refer to: * Humpback whale * Humpback dolphin * Humpback salmon * Humpback bridge * Humpback, a common name for the fish ''Chanodichthys dabryi'' * Humpback, a variant of hunchback Kyphosis is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. Abnormal inward concave ''lordotic'' curving of the cervical and lumbar regions of the spine is called lordosis. It can result fr ... {{disambiguation, fish Animal common name disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise Pollution
Noise pollution, also known as environmental noise or sound pollution, is the propagation of noise with ranging impacts on the activity of human or animal life, most of them are harmful to a degree. The source of outdoor noise worldwide is mainly caused by machines, transport, and propagation systems.Senate Public Works Committee. ''Noise Pollution and Abatement Act of 1972''. S. Rep. No. 1160, 92nd Congress. 2nd session Poor urban planning may give rise to noise disintegration or pollution, side-by-side industrial and residential buildings can result in noise pollution in the residential areas. Some of the main sources of noise in residential areas include loud music, transportation (traffic, rail, airplanes, etc.), lawn care maintenance, construction, electrical generators, wind turbines, explosions, and people. Documented problems associated with noise in urban environments go back as far as ancient Rome. Research suggests that noise pollution in the United States is the high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray Whale
The gray whale (''Eschrichtius robustus''), also known as the grey whale,Britannica Micro.: v. IV, p. 693. gray back whale, Pacific gray whale, Korean gray whale, or California gray whale, is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of , a weight of up to and lives between 55 and 70 years, although one female was estimated to be 75–80 years of age. The common name of the whale comes from the gray patches and white mottling on its dark skin. Gray whales were once called devil fish because of their fighting behavior when hunted. The gray whale is the sole living species in the genus ''Eschrichtius''. It was formerly thought to be the sole living genus in the family (biology), family Eschrichtiidae, but more recent evidence classifies members of that family in the family Rorqual, Balaenopteridae. This mammal is descended from filter-feeding whales that appeared during the Neogene. The gray whale is distributed in an eastern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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