User:Edixon426/Great white shark

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Distribution and habitat
Great white sharks live in almost all coastal and offshore waters which have water temperature between 12 and 24 °C (54 and 75 °F), with greater concentrations in the United States (Northeast and California), South Africa, Japan, Oceania, Chile, and the Mediterranean including Sea of Marmara and Bosphorus.[24][25] One of the densest known populations is found around Dyer Island, South Africa.[26]

The great white is an epipelagic fish, observed mostly in the presence of rich game, such as fur seals (Arctocephalus ssp.), sea lions, cetaceans, other sharks, and large bony fish species. In the open ocean, it has been recorded at depths as great as 1,200 m (3,900 ft).[11] These findings challenge the traditional notion that the great white is a coastal species.[11]

According to a recent study, California great whites have migrated to an area between Baja California Peninsula and Hawaii known as the White Shark Café to spend at least 100 days before migrating back to Baja. On the journey out, they swim slowly and dive down to around 900 m (3,000 ft). After they arrive, they change behavior and do short dives to about 300 m (980 ft) for up to ten minutes. Another white shark that was tagged off the South African coast swam to the southern coast of Australia and back within the year. A similar study tracked a different great white shark from South Africa swimming to Australia's northwestern coast and back, a journey of 20,000 km (12,000 mi; 11,000 nmi) in under nine months.[27] These observations argue against traditional theories that white sharks are coastal territorial predators, and open up the possibility of interaction between shark populations that were previously thought to have been discrete. The reasons for their migration and what they do at their destination is still unknown. Possibilities include seasonal feeding or mating.[28]

In the Northeast Atlantic the white shark populations off the New England coast were nearly eradicated due to over-fishing. However, in recent years the populations have begun to grow greatly, '''largely due to the increase in seal populations on Cape Cod, Massachusetts since the enactment of the Marine Mammal Protection Act in 1972. Currently very little is known about the hunting and movement patterns of great whites off Cape Cod, but ongoing studies hope to offer insight into this growing shark population. '''

A 2018 study indicated that white sharks prefer to congregate deep in anticyclonic eddies in the North Atlantic Ocean. The sharks studied tended to favor the warm water eddies, spending the daytime hours at 450 meters and coming to the surface at night.[29]

Diet[edit]
Off California, sharks immobilize northern elephant seals (Mirounga angustirostris) with a large bite to the hindquarters (which is the main source of the seal's mobility) and wait for the seal to bleed to death. This technique is especially used on adult male elephant seals, which are typically larger than the shark, ranging between 1,500 and 2,000 kg (3,300 and 4,400 lb), and are potentially dangerous adversaries.[70][71] Most commonly though, juvenile elephant seals are the most frequently eaten at elephant seal colonies.[72] Prey is normally attacked sub-surface. Harbor seals (Phoca vitulina) are taken from the surface and dragged down until they stop struggling. They are then eaten near the bottom. California sea lions (Zalophus californianus) are ambushed from below and struck mid-body before being dragged and eaten.[73]

'''In the Northwest Atlantic mature great whites are known to feed on both Harbor and Grey Seals.  Unlike adults, juvenile white sharks in the area feed on smaller fish species until they are large enough to prey on marine mammals such as seals.'''

White sharks also attack dolphins and porpoises from above, behind or below to avoid being detected by their echolocation. Targeted species include dusky dolphins (Lagenorhynchus obscurus),[44] Risso's dolphins (Grampus griseus),[44] bottlenose dolphins (Tursiops ssp.),[44][74] Humpback dolphins (Sousa ssp.),[74] harbour porpoises (Phocoena phocoena),[44] and Dall's porpoises (Phocoenoides dalli).[44]Groups of dolphins have occasionally been observed defending themselves from sharks with mobbing behaviour.[74] White shark predation on other species of small cetacean has also been observed. In August 1989, a 1.8 m (5.9 ft) juvenile male pygmy sperm whale (Kogia breviceps) was found stranded in central California with a bite mark on its caudal peduncle from a great white shark.[75] In addition, white sharks attack and prey upon beaked whales.[44][74] Cases where an adult Stejneger's beaked whale (Mesoplodon stejnegeri), with a mean mass of around 1,100 kg (2,400 lb),[76] and a juvenile Cuvier's beaked whale (Ziphius cavirostris), an individual estimated at 3 m (9.8 ft), were hunted and killed by great white sharks have also been observed.[77] When hunting sea turtles, they appear to simply bite through the carapace around a flipper, immobilizing the turtle. The heaviest species of bony fish, the oceanic sunfish (Mola mola), has been found in great white shark stomachs.[67]