The Great White Shark
The great white shark, Carcharodon carcharias, also known as white pointer, white shark, or white death, is an exceptionally large lamniform shark found in coastal surface waters in all major oceans. Reaching lengths of more than 6 m (20 ft) and weighing up to 2,250 kg (5,000 lb), the great white shark is arguably the world’s largest known predatory fish. It is the only surviving species of its genus, Carcharodon.
Distribution and habitat
Great white sharks live in almost all coastal and offshore waters which have a water temperature of between 12 and 24° C (54° to 75° F), with greater concentrations off the southern coasts of Australia, off South Africa, California, Mexico’s Isla Guadalupe and to a degree in the Central Mediterranean and Adriatic Seas. One of the densest known populations is found around Dyer Island, South Africa where much research on the shark is conducted. It can be also found in tropical waters like those of the Caribbean, and has been recorded off Mauritius, Madagascar, Kenya and the Seychelles. It is an epipelagic fish, but recorded or observed mostly in inland tributaries in the presence of rich game like fur seals, sea lions, cetaceans, other sharks and large bony fish species. It is considered an open-ocean dweller and is recorded from the surface down to depths of 1,280 m (4,200 ft), but is most often found close to the surface.
In a recent study great white sharks from California were shown to migrate to an area between Baja California and Hawaii, where they spend at least 100 days of the year before they migrate 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 10 minutes. Another white shark tagged off the coast of South Africa swam to the southern coast of Australia and back within the space of a year. This had disproved traditional theories of white sharks being coastal territorial predators and opens up the possibility of interaction between white shark populations that were previously thought to be discrete from one another,and It is still unknown why they migrate and what they do there; it might be seasonal feeding or possibly a mating area.
In a similar study a great white shark from South Africa was tracked swimming to the northwestern coast of Australia and back to the same location in South Africa, a journey of 20,000 km (12,000 mi) in under 9 months.
Anatomy and appearance
Great white sharks display countershading, having a white underside and a grey dorsal area (sometimes in a brown or blue shade) that gives an overall “mottled” appearance. The colouration makes it difficult for prey to spot the shark because it breaks up the shark’s outline when seen from a lateral perspective. When viewed from above, the darker shade blends in with the sea and when seen from below casts a minimal silhouette against the sunlight.
Great white sharks, like many other sharks, have rows of teeth behind the main ones, allowing any that break off to be rapidly replaced. A great white shark’s teeth are serrated and when the shark bites it will shake its head side to side and the teeth will act as a saw and tear off large chunks of flesh. Great white sharks often swallow their own broken off teeth along with chunks of their prey’s flesh.
A typical adult great white shark measures 4 to 4.8 m (13 to 16 ft) with a typical weight of 680 to 1,100 kg (1,500 to 2,450 lb), females generally being larger than males. The maximum size of the great white shark has been subject to much debate, conjecture, and misinformation. Richard Ellis and John E. McCosker, both academic shark experts, devote a full chapter in their book, Great White Shark (1991), to analysing various accounts of extreme size.
Today, most experts contend that the great white shark’s “normal” maximum size is about 6 m (20 ft), with a “normal” maximum weight of about 1,900 kg (4,200 lb).
For several decades, many ichthyological works, as well as the Guinness Book of World Records, listed two great white sharks as the largest individuals caught: an 11 m (36 ft) great white captured in Southern Australian waters near Port Fairy in the 1870s, and an 11.3 m (37 ft) shark trapped in a herring weir in New Brunswick, Canada in the 1930s. While this was the commonly accepted maximum size, reports of 7.5 to 10 metre (25 to 33.3 ft) great white sharks were common and often deemed credible.
Great white shark caught off Hualien County, Taiwan on May 14, 1997. It was reportedly almost 7 metres in length and weighing 2500 kg.
Some researchers questioned the reliability of both measurements, noting they were much larger than any other accurately-reported great white shark. The New Brunswick shark may have been a misidentified basking shark, as both sharks have similar body shapes. The question of the Port Fairy shark was settled in the 1970s, when J.E. Reynolds examined the shark’s jaws and “found that the Port Fairy shark was of the order of 5 m (17 ft) in length and suggested that a mistake had been made in the original record, in 1870, of the shark’s length.
Ellis and McCosker write that “the largest White Sharks accurately measured range between 19 ft (5.8 m) and 21 ft (6.4 m), and there are some questionable 23-footers [about 7 m] in the popular — but not the scientific — literature”. Furthermore, they add that “these giants seem to disappear when a responsible observer approaches with a tape measure.” (For more about legendary exaggerated shark measurements, see the submarine).
The largest specimen Ellis and McCosker endorse as reliably measured was 6.4 m (21 ft) long, caught in Cuban waters in 1945; though confident in their opinion, Ellis and McCosker note other experts have argued this individual might have been a few feet shorter. The unverified weight reported for the shark from Cuba was 3270 kg (7200 lbs). There have since been claims of larger great white sharks, but, as Ellis and McCosker note, verification is often lacking and these extraordinarily large great white sharks have, upon examination, all proved under the 20-21 ft limit. For example, a much-publicized female great white said to be 7.13 m (23.4 ft) was fished in Malta in 1987 by Alfredo Cutajar. In their book, Ellis and McCosker agree this shark seemed to be larger than average, but they did not endorse the 7.13 m (23.4 ft) measurement. In the years since, experts eventually found reason to doubt the claim, due in no small part to conflicting accounts offered by Cutajar and others. A BBC photo analyst concluded that even “allowing for error … the shark is concluded to be in the 18.3 ft (5.6 m) range and in no way approaches the 23 ft (7.0 m) reported by Abela.” (as in original)
According to the Canadian Shark Research Centre, the largest accurately measured great white shark was a female caught in August 1988 at Prince Edward Island off the Canadian (North Atlantic) coast and measured 6.1 m (20 ft). The shark was caught by David McKendrick, a local resident from Alberton, West Prince.
The question of maximum weight is complicated by the unresolved question of whether or not to account for the weight of a shark’s recent meals when weighing the shark itself. With a single bite, a great white can take in up to 14 kg (31 lb) of flesh, and can gorge on several hundred kilograms or pounds of food.
Ellis and McCosker write in regards to modern great white sharks that “it is likely that [Great White] sharks can weigh as much as 2 tons”, but also note that the largest recent scientifically measured examples weigh in at about 2 tonnes (2.2 short tons). Other large, predatory sharks may grow to comparable lengths as the Great White, including the Tiger Shark, the Greenland Shark and the Pacific sleeper shark. However, the Great White is, by far, the mostly massively-built predatory shark to exceed 6 meters (20 feet) and is the only one to be weighed at more than 2 tons.
The largest great white shark recognized by the International Game Fish Association (IGFA) is one landed by Alf Dean in south Australian waters in 1959, weighing 1,208 kg (2,660 lb). Several larger great white sharks caught by anglers have since been verified, but were later disallowed from formal recognition by IGFA monitors for rules violations.
Close to Shore: A True Story of Terror in an Age of Innocence is a non-fiction book by journalist Michael Capuzzo about the Jersey Shore shark attacks of 1916. The book was published in 2001 by Broadway Books. Capuzzo argues that the five victims were attacked by a great white shark, though others believe that the attacks were done by a bull shark.
According to the afterword, Capuzzo spent two years researching not only the shark attacks but also the time period so he could gain a better understanding of the lives of the Victorians affected by the attacks. In addition to research in newspapers and contemporary journals and letters, Capuzzo visited the sites and together with George Burgess tested the waters of Matawan Creek to see if it was possible that a great white shark entered.
The book goes into great detail about the people involved and their lives and motivations, as well as recounting the grisly facts of each of the attack