The great white shark (Carcharodon carcharias), also known as the white shark, white pointer, or simply great white, is a species of large 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 6.1 m (20 ft) in length and 1,905–2,268 kg (4,200–5,000 lb) in weight at maturity.
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. One of the densest-known populations is found around Dyer Island, South Africa. Juvenile great white sharks inhabit a more narrow band of temperatures (between 14 and 24 °C (57 and 75 °F)) in shallow coastal nurseries. Increased observation of young sharks in areas they were not previously common, such as Monterey Bay on the Central California coast, suggest climate change may be reducing the range of juvenile great white sharks and shifting it toward the poles.
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). These findings challenge the traditional notion that the great white is a coastal species.
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 behaviour 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. 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.
In great white sharks, sexual dimorphism is present, and females are generally larger than males. Male great whites on average measure 3.4 to 4.0 m (11 to 13 ft) long, while females at 4.6 to 4.9 m (15 to 16 ft).[6] Adults of this species weigh 522–771 kg (1,151–1,700 lb) on average;[61] however, mature females can have an average mass of 680–1,110 kg (1,500–2,450 lb).[4] The largest females have been verified up to 6.1 m (20 ft) in length and an estimated 1,905 kg (4,200 lb) in weight,[4] perhaps up to 2,268 kg (5,000 lb).[5] The maximum size is subject to debate because some reports are rough estimations or speculations performed under questionable circumstances.[62] Among living cartilaginous fish, only the whale shark (Rhincodon typus), the basking shark (Cetorhinus maximus) and the giant manta ray (Manta birostris), in that order, are on average larger and heavier. These three species are generally quite docile in disposition and given to passively filter-feeding on very small organisms. This makes the great white shark the largest extant macropredatory fish. Great white sharks are at around 1.2 m (3.9 ft) when born, and grow about 25 cm (9.8 in) each year.
A 2007 study from the University of New South Wales in Sydney, Australia, used CT scans of a shark's skull and computer models to measure the shark's maximum bite force. The study reveals the forces and behaviours its skull is adapted to handle and resolves competing theories about its feeding behaviour.[105] In 2008, a team of scientists led by Stephen Wroe conducted an experiment to determine the great white shark's jaw power and findings indicated that a specimen massing 3,324 kg (7,328 lb) could exert a bite force of 18,216 newtons (4,095 lbf).
This shark's behaviour and social structure are complex. In South Africa, white sharks have a dominance hierarchy depending on the size, sex and squatter's rights: Females dominate males, larger sharks dominate smaller sharks, and residents dominate newcomers. When hunting, great whites tend to separate and resolve conflicts with rituals and displays. White sharks rarely resort to combat although some individuals have been found with bite marks that match those of other white sharks. This suggests that when a great white approaches too closely to another, they react with a warning bite. Another possibility is that white sharks bite to show their dominance. Data acquired from animal-borne telemetry receivers and published in 2022 via the journal Royal Society Publishing suggests that individual great whites may associate so that they can inadvertently share information on the whereabouts of prey or the location of the remains of animals that can be scavenged. As biologging can help to reveal social habits, it allows a better understanding to be made in future studies regarding the full extent of social interactions in large marine animals, including the great white shark.
Great white sharks are carnivorous and prey upon fish (e.g. tuna, rays, other sharks),[108] cetaceans (i.e., dolphins, porpoises, whales), pinnipeds (e.g. seals, fur seals,[108] and sea lions), sea turtles,[108] sea otters (Enhydra lutris) and seabirds.[111] Great whites have also been known to eat objects that they are unable to digest. Juvenile white sharks predominantly prey on fish, including other elasmobranchs, as their jaws are not strong enough to withstand the forces required to attack larger prey such as pinnipeds and cetaceans until they reach a length of 3 m (9.8 ft) or more, at which point their jaw cartilage mineralizes enough to withstand the impact of biting into larger prey species.[112] Upon approaching a length of nearly 4 m (13 ft), great white sharks begin to target predominantly marine mammals for food, though individual sharks seem to specialize in different types of prey depending on their preferences.[113][114] They seem to be highly opportunistic. These sharks prefer prey with a high content of energy-rich fat. Shark expert Peter Klimley used a rod-and-reel rig and trolled carcasses of a seal, a pig, and a sheep from his boat in the South Farallons. The sharks attacked all three baits but rejected the sheep carcass.
Off of Seal Island, False Bay in South Africa, the sharks ambush brown fur seals (Arctocephalus pusillus) from below at high speeds, hitting the seal mid-body. They achieve high speeds that allow them to completely breach the surface of the water. The peak burst speed is estimated to be above 40 km/h (25 mph).[118] They have also been observed chasing prey after a missed attack. Prey is usually attacked at the surface.[119] Shark attacks occur most often in the morning, within two hours of sunrise, when visibility is poor. Their success rate is 55% in the first two hours, falling to 40% in late morning after which hunting stops.
Great white sharks were previously thought to reach sexual maturity at around 15 years of age, but are now believed to take far longer; male great white sharks reach sexual maturity at age 26, while females take 33 years to reach sexual maturity.[9][137][138] Maximum life span was originally believed to be more than 30 years, but a study by the Woods Hole Oceanographic Institution placed it at upwards of 70 years. Examinations of vertebral growth ring count gave a maximum male age of 73 years and a maximum female age of 40 years for the specimens studied. The shark's late sexual maturity, low reproductive rate, long gestation period of 11 months and slow growth make it vulnerable to pressures such as overfishing and environmental change.
Little is known about the great white shark's mating habits, and mating behaviour had not been observed in this species until 1997 and properly documented in 2020. It was assumed previously to be possible that whale carcasses are an important location for sexually mature sharks to meet for mating. According to the testimony of fisherman Dick Ledgerwood, who observed two great white sharks mating in the area near Port Chalmers and Otago Harbor, in New Zealand, it is theorized that great white sharks mate in shallow water away from feeding areas and continually roll belly to belly during copulation.[139] Birth has never been observed, but pregnant females have been examined. Great white sharks are ovoviviparous, which means eggs develop and hatch in the uterus and continue to develop until birth.[140] The great white has an 11-month gestation period. The shark pup's powerful jaws begin to develop in the first month. The unborn sharks participate in oophagy, in which they feed on ova produced by the mother. Delivery is in spring and summer.[141] The largest number of pups recorded for this species is 14 pups from a single mother measuring 4.5 m (15 ft) that was killed incidentally off Taiwan in 2019.
