The
great white shark, scientific name
Carcharodon carcharias, also known as the
great white,
white pointer,
white shark, or
white death, is a large
lamniformLamniformes is an order of sharks commonly known as mackerel sharks . It includes some of the most familiar species of sharks, such as the great white shark, as well as more unusual representatives, such as the goblin shark and the megamouth shark.Members of the order are distinguished by...
sharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
found in coastal surface waters in all major
oceanAn ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
s. It is known for its size, with the largest individuals known to have approached or exceeded 6 metres (20 ft) in length, and 2268 kilograms (5,000 lb) in weight. This shark reaches
maturitySexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
at around 15 years of age and can have a life span of over 30 years.
The great white shark is arguably the world's largest known extant macropredatory fish and is one of the primary predators of
marine mammalMarine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
s. It is also known to prey upon a variety of other marine animals including
fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
,
pinnipedPinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
s, and
seabirdSeabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s. It is the only known surviving
speciesIn biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of its
genusIn biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
,
Carcharodon, and is ranked first in a list of number of recorded attacks on humans. The IUCN treats the great white shark as
vulnerableOn 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
, while it is included in Appendix II of CITES.
The best selling novel
JawsJaws is a 1974 novel by Peter Benchley. It tells the story of a great white shark that preys upon a small resort town, and the voyage of three men to kill it....
by
Peter BenchleyPeter Bradford Benchley was an American author, best known for his novel Jaws and its subsequent film adaptation, the latter co-written by Benchley and directed by Steven Spielberg...
and the subsequent
blockbuster filmJaws is a 1975 American horror-thriller film directed by Steven Spielberg and based on Peter Benchley's novel of the same name. In the story, the police chief of Amity Island, a fictional summer resort town, tries to protect beachgoers from a giant man-eating great white shark by closing the beach,...
by
Steven SpielbergSteven Allan Spielberg KBE is an American film director, screenwriter, producer, video game designer, and studio entrepreneur. In a career of more than four decades, Spielberg's films have covered many themes and genres. Spielberg's early science-fiction and adventure films were seen as an...
depicted the great white shark as a "ferocious man eater". In reality, humans are not the preferred prey of the great white shark.
Etymology
Carolus LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
gave the great white shark its first scientific name,
Squalus carcharias, in 1758.
Sir Andrew SmithSir Andrew Smith KCB was a Scottish surgeon, explorer, ethnologist and zoologist. He is considered the father of Zoology in South Africa having described many species across a wide range of groups in his major work, Illustrations of the Zoology of South Africa.Smith was born in Hawick, Roxburghshire...
gave it the
genericIn biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name
Carcharodon in 1833, and in 1873 the generic name was identified with Linnaeus' specific name and the current scientific name
Carcharodon carcharias was finalised.
Carcharodon comes from the
GreekGreek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
words
karcharos, which means sharp or jagged, and
odous, which means tooth.
Ancestry and fossil record
The great white shark came into existence during the Mid-
MioceneThe Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
epoch. The earliest known fossils are about 16 million years old. However, the phylogeny of the great white is still in dispute. The original hypothesis for the great white's origins is that it shares a common ancestor with a prehistoric shark,
C. megalodonThe megalodon and ὀδούς ) is an extinct species of shark that lived roughly from 28 to 1.5 million years ago, during the Cenozoic Era .The taxonomic assignment of C...
. Similarities among the physical remains and the extreme size of both the great white and
C. megalodon led many scientists to believe that these sharks were closely related, and the name
Carcharodon megalodon was applied to the latter. However, a new hypothesis proposes that
C. megalodon and the great white are distant relatives (albeit sharing the family
LamnidaeLamnidae is a family of sharks, commonly known as mackerel sharks or white sharks. They are large, fast-swimming sharks, found in oceans worldwide....
), and that the great white is more closely related to an ancient mako shark,
Isurus hastalis, than to
C. megalodon. In addition, the new hypothesis assigns
C. megalodon to the
Carcharocles genus, which also comprises other megatoothed sharks, and
Otodus obliquusOtodus obliquus is an extinct mackerel shark which lived during the Paleocene and Eocene epochs, approximately about 60 to 37.5 million years ago.-Known physiology:This shark is known from the fossil teeth and fossilized vertebral centra...
is the ancient representative of the extinct
Carcharocles lineage.
Distribution and habitat
Great white sharks live in almost all coastal and offshore waters which have water temperature between 12 and 24 °C (53.6 and 75.2 F), with greater concentrations in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
(
Atlantic NortheastThe Atlantic Northeast, or Arcadia, is a region of North America, comprising New Hampshire, Vermont, Maine and the Canadian Maritimes. Definitions of the region vary; it may extend to upstate New York and/or all of Atlantic Canada....
and
CaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
),
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
,
JapanJapan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
(especially
New South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
and
South AustraliaSouth Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
),
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
,
ChileChile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, and the
MediterraneanThe Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. One of the densest known populations is found around
Dyer Island, South AfricaGansbaai is a fishing village and popular tourist destination in the Overberg District Municipality, Western Cape, South Africa...
where much shark research is conducted.
It is an
epipelagicAny water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
fish, observed mostly in the presence of rich game like
fur sealFur seals are any of nine species of pinnipeds in the Otariidae family. One species, the northern fur seal inhabits the North Pacific, while seven species in the Arctocephalus genus are found primarily in the Southern hemisphere...
s,
sea lionSea lions are pinnipeds characterized by external ear-flaps, long fore-flippers, the ability to walk on all fours, and short thick hair. Together with the fur seal, they comprise the family Otariidae, or eared seals. There are six extant and one extinct species in five genera...
s, cetaceans, other sharks, and large bony fish species. In the open ocean it has been recorded at depths as great as 1220 m (4,002.6 ft). These findings challenge the traditional notion about the great white as being a coastal species.
According to a recent study,
CaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
great whites have migrated to an area between
Baja CaliforniaBaja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
and
HawaiiHawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
known as
White Shark CaféThe White Shark Café is a remote mid-Pacific Ocean area noted as a winter and spring habitat of otherwise coastal great white sharks.The area, halfway between Baja California and Hawaii, received its unofficial name in 2002 from researchers at the Monterey Bay Aquarium Research Institute who were...
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 (2,952.8 ft). After they arrive, they change behavior and do short dives to about 300 m (984.3 ft) for up to 10 minutes. Another white shark tagged off the South African coast swam to the southern coast of Australia and back within the year. This refuted traditional theories that white sharks are coastal territorial predators and opens up the possibility of interaction between shark populations that were previously thought to be discrete. Why they migrate and what they do at their destination is still unknown. Possibilities include seasonal feeding or mating.
A similar study tracked a great white shark from South Africa swimming to Australia's northwestern coast and back, a journey of 20000 km (12,427.5 mi; 10,799.1 nmi) in under 9 months.
Anatomy and appearance
The great white shark has a robust large conical snout. The upper and lower
lobesIn anatomy, a lobe is a clear anatomical division or extension that can be determined without the use of a microscope This is in contrast to a lobule, which is a clear division only visible histologically....
on the tail fin are approximately the same size (like some mackerel sharks).
Great whites display
countershadingCountershading, or Thayer's Law, is a form of camouflage. Countershading, in which an animal’s pigmentation is darker dorsally, is often thought to have an adaptive effect of reducing conspicuous shadows cast on the ventral region of an animal’s body...
, having a white underside and a grey dorsal area (sometimes in a brown or blue shade) that gives an overall mottled appearance. The coloration makes it difficult for prey to spot the shark because it breaks up the shark's outline when seen from the side. From above, the darker shade blends with the sea and from below it exposes a minimal silhouette against the sunlight.
Great white sharks, like many other sharks, have
rows of serrated teethA shark tooth is one of the numerous teeth of a shark. Sharks continually shed their teeth, and some Carcharhiniformes shed approximately 35,000 teeth in a lifetime. In some geological formations, shark's teeth are a common fossil...
behind the main ones, ready to replace any that break off. When the shark bites it shakes its head side to side, helping the teeth saw off large chunks of flesh.
Size
Males reach maturity at 3.5–4 m (11.5–13.1 ft) and females at 4.5–5 m (14.8–16.4 ft). Adults on average are 4–5.2 m (13.1–17.1 ft) long and have a mass of 680–1100 kg (1,499.1–2,425.1 lb). Females are generally larger than males. It is widely accepted that the great white shark can reach 6.1 m (20 ft) in length and 1900 kg (4,188.8 lb) in weight. The maximum size is subject to debate because some reports are rough estimations or speculations performed under questionable circumstances.
A number of very large great white shark specimens have been recorded. For decades, many ichthyological works as well as the
Guinness Book of World Records listed two great white sharks as the largest individuals: A 10.9 m (35.8 ft) great white captured in Southern
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n waters near
Port FairyPort Fairy is a coastal town in south-western Victoria, Australia. It lies on the Princes Highway in the Shire of Moyne, west of Warrnambool and 290 km west of Melbourne, at the point where the Moyne River enters the Southern Ocean.-History:...
, in the 1870s, and a 11.3 m (37.1 ft) shark trapped in a
herringHerring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
weirA fishing weir, or fish weir, is an obstruction placed in tidal waters or wholly or partially across a river, which is designed to hinder the passage of fish. Traditionally they were built from wood or stones. They can be used to trap fish...
in
New BrunswickNew Brunswick is one of Canada's three Maritime provinces and is the only province in the federation that is constitutionally bilingual . The provincial capital is Fredericton and Saint John is the most populous city. Greater Moncton is the largest Census Metropolitan Area...
,
CanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, in the 1930s. Some researchers question these measurements' reliability, noting they were much larger than any other accurately reported sighting. The New Brunswick shark may have been a misidentified
basking sharkThe basking shark is the second largest living fish, after the whale shark. It is a cosmopolitan migratory species, found in all the world's temperate oceans. It is a slow moving and generally harmless filter feeder and has anatomical adaptations to filter feeding, such as a greatly enlarged...
as the two have similar body shapes. The question of the Port Fairy shark was settled in the 1970s when J. E. Randall 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".
According to J. E. Randall, the largest white shark reliably measured was a 6 m (19.7 ft) individual reported from Ledge Point, Western
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, in 1987. Another great white specimen of similar size has been verified by the Canadian Shark Research Center: A female caught by David McKendrick of
AlbertonAlberton is a Canadian town located in the western part of Prince County, Prince Edward Island. It is situated in the township of Lot 5....
,
Prince Edward IslandPrince Edward Island is a Canadian province consisting of an island of the same name, as well as other islands. The maritime province is the smallest in the nation in both land area and population...
, in August 1988 in the Gulf of St. Lawrence off PEI. This female great white was 6.1 m (20 ft) long. However, a larger great white shark specimen was verified by T. C. Tricas and J. E. McCosker in 1984. This specimen was 6.4 m (21 ft) long and had a body mass of about 3324 kg (7,328.2 lb).
Several great white sharks caught in modern times have been estimated to be more than 7 m (23 ft) long, but these claims have received some criticism. However, J. E. Randall believed that great white shark may have exceeded 6.1 m (20 ft) in length. A great white shark was captured near
Kangaroo IslandKangaroo Island is Australia's third-largest island after Tasmania and Melville Island. It is southwest of Adelaide at the entrance of Gulf St Vincent. Its closest point to the mainland is off Cape Jervis, on the tip of the Fleurieu Peninsula in the state of South Australia. The island is long...
in
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
on April 1, 1987. This shark was estimated to be more than 7 m (23 ft) long by Peter Resiley, and has been designated as KANGA. Another great white shark was caught in
MaltaMalta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...
by Alfredo Cutajar on April 16, 1987. This shark was also estimated to be around 7.13 m (23.4 ft) long by John Abela and has been designated as MALTA. However, Cappo drew criticism because he used shark size estimation methods proposed by J. E. Randall to suggest that the KANGA specimen was 5.8–6.4 m (19–21 ft) long. In the similar fashion, I. K. Fergusson also used shark size estimation methods proposed by J. E. Randall to suggest that the MALTA specimen was 5.3–5.7 m (17.4–18.7 ft) long. However, photographic evidence suggested that these specimens were larger than the size estimations yielded through Randall's methods. Thus, a team of scientists, H. F. Mollet, G. M. Cailliet, A. P. Klimley, D. A. Ebert, A. D. Testi, and
L. J. V. CompagnoLeonard Joseph Victor Compagno is an international authority on shark taxonomy and the author of many scientific papers and books on the subject, best known of which is his 1984 catalogue of shark species produced for the Food and Agriculture Organization of the United Nations.-Career:*Ph.D,...
, reviewed the cases of the KANGA and MALTA specimens in 1996 to resolve the dispute by conducting a comprehensive morphometric analysis of the remains of these sharks and re-examination of photographic evidence in an attempt to validate the original size estimations and their findings were consistent with them. The findings indicated that estimations by P. Resiley and J. Abela are reasonable and cannot be ruled out.
A close contender in size is the
tiger sharkThe tiger sharks, Galeocerdo cuvier, is a species of requiem shark and the only member of the genus Galeocerdo. Commonly known as sea tigers, tiger sharks are relatively large macropredators, capable of attaining a length of over . It is found in many tropical and temperate waters, and is...
,
Galeocerdo cuvier, with the largest specimen reported to have been 7.4 metres (24.3 ft) in length with a mass of 3110 kilograms (6,856.4 lb). Some other macropredatory sharks such as the
Greenland SharkThe Greenland shark, Somniosus microcephalus, also known as the sleeper shark, gurry shark, ground shark, grey shark, or by the Inuit languages name Eqalussuaq, is a large shark native to the waters of the North Atlantic Ocean around Greenland and Iceland. These sharks live farther north than any...
,
Somniosus microcephalus, and the
Pacific sleeper sharkThe Pacific sleeper shark, Somniosus pacificus, is a sleeper shark of the family Somniosidae, found circumglobally on continental shelves and slopes in temperate waters between latitudes 70°N and 47°S, from the surface to...
,
Somniosus pacificus, are also known to rival these sharks in length. The question of maximum weight is complicated by the unresolved question of whether or not to include the shark's stomach contents when weighing the shark. With a single bite a great white can take in up to 14 kg (30.9 lb) of flesh, and can consume several hundred kilograms of food.
The largest great white recognized by the
International Game Fish AssociationThe International Game Fish Association is the leading authority on angling pursuits and the keeper of the most current World Record fishing catches by fish categories. Fishermen who are sport fishers are careful to follow their stringent rules for fair play and line requirements in order to...
(IGFA) is one landed by Alf Dean in south Australian waters in 1959, weighing 1208 kg (2,663.2 lb). Several larger great whites caught by anglers have since been verified, but were later disallowed from formal recognition by IGFA monitors for rules violations.
Adaptations
Great white sharks, like all other sharks, have an extra sense given by the
Ampullae of LorenziniThe ampullae of Lorenzini are special sensing organs called electroreceptors, forming a network of jelly-filled pores. They are mostly discussed as being found in cartilaginous fishes ; however, they are also reported to be found in Chondrostei such as Reedfish and sturgeon. Lungfish have also been...
which enables them to detect the electromagnetic field emitted by the movement of living animals. Every time a living creature moves, it generates an electrical field and great whites are so sensitive they can detect half a billionth of a
voltThe volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
. Even heart beats emit a very faint electrical pulse. If it is close enough, the shark can detect even that faint electrical pulse. Most fish have a less-developed but similar sense using their body's
lateral lineThe lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
.
To more successfully hunt fast and agile prey such as sea lions, the great white has adapted to maintain a body temperature warmer than the surrounding water. One of these adaptations is a "
rete mirabileA rete mirabile is a complex of arteries and veins lying very close to each other, found in some vertebrates. The rete mirabile utilizes countercurrent blood flow within the net...
" (Latin for "wonderful net"). This close web-like structure of veins and arteries, located along each lateral side of the shark, conserves heat by warming the cooler arterial blood with the venous blood that has been warmed by the working muscles. This keeps certain parts of the body (particularly the stomach) at temperatures up to 14°C (25°F) above that of the surrounding water, while the heart and gills remain at sea temperature. When conserving energy the core body temperature can drop to match the surroundings. A great white shark's success in raising its core temperature is an example of
gigantothermyGigantothermy is a phenomenon with significance in biology and paleontology, whereby large, bulky ectothermic animals are more easily able to maintain a constant, relatively high body temperature than smaller animals by virtue of their smaller surface area to volume ratio...
. Therefore, the great white shark can be considered an
endothermicIn thermodynamics, the word endothermic describes a process or reaction in which the system absorbs energy from the surroundings in the form of heat. Its etymology stems from the prefix endo- and the Greek word thermasi,...
poikilothermA poikilotherm is an organism whose internal temperature varies considerably. It is the opposite of a homeotherm, an organism which maintains thermal homeostasis. Usually the variation is a consequence of variation in the ambient environmental temperature...
because its body temperature is not constant but is internally regulated.
Bite force
A 2007 study from the
University of New South WalesThe University of New South Wales , is a research-focused university based in Kensington, a suburb in Sydney, New South Wales, Australia...
in
SydneySydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
,
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, used CT scans of a shark's skull and computer models to measure maximum bite force. The study reveals the forces and behaviors its skull is adapted to handle and resolves competing theories about its feeding behavior. 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 more than 6.1 m (20 ft) long could exert a bite force of over 18000 newtons (4,046.6 lbf).
Ecology and behavior
This shark's behavior and social structure is not well understood. In South Africa, white sharks have a
dominance hierarchyA dominance hierarchy is the organization of individuals in a group that occurs when competition for resources leads to aggression...
depending on 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 another shark approaches too closely, great whites react with a warning bite. Another possibility is that white sharks bite to show dominance.
The great white shark is one of only a few sharks known to regularly lift its head above the sea surface to gaze at other objects such as prey. This is known as spy-hopping. This behavior has also been seen in at least one group of
blacktip reef sharkThe blacktip reef shark is a species of requiem shark, family Carcharhinidae, easily identified by the prominent black tips on its fins...
s, but this might be learned from interaction with humans (it is theorized that the shark may also be able to smell better this way because smell travels through air faster than through water). The white sharks are generally very curious animals, display intelligence and may also turn to socializing if the situation demands it. At Seal Island, white sharks have been observed arriving and departing in stable "clans" of two to six individuals on a yearly basis. Whether clan members are related is unknown but they get along peacefully enough. In fact, the social structure of a clan is probably most aptly compared to that of a wolf pack in that each member has a clearly established rank and each clan has an alpha leader. When members of different clans meet, they establish social rank nonviolently through any of a fascinating variety of interactions.
Diet
Great white sharks are carnivorous and prey upon
fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
(e.g.
tunaTuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...
,
rayBatoidea is a superorder of cartilaginous fish commonly known as rays and skates, containing more than 500 described species in thirteen families...
s, other
sharkSharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
s), cetaceans (i.e.,
dolphinDolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s,
porpoisePorpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen...
s,
whaleWhale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s),
pinnipedPinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
s (e.g.
sealThe true seals or earless seals are one of the three main groups of mammals within the seal superfamily, Pinnipedia. All true seals are members of the family Phocidae . They are sometimes called crawling seals to distinguish them from the fur seals and sea lions of the family Otariidae...
s,
fur sealFur seals are any of nine species of pinnipeds in the Otariidae family. One species, the northern fur seal inhabits the North Pacific, while seven species in the Arctocephalus genus are found primarily in the Southern hemisphere...
s, and
sea lionSea lions are pinnipeds characterized by external ear-flaps, long fore-flippers, the ability to walk on all fours, and short thick hair. Together with the fur seal, they comprise the family Otariidae, or eared seals. There are six extant and one extinct species in five genera...
s),
sea turtleSea turtles are marine reptiles that inhabit all of the world's oceans except the Arctic.-Distribution:...
s,
sea otterThe sea otter is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg , making them the heaviest members of the weasel family, but among the smallest marine mammals...
s, and seabirds. Great whites have also been known to eat objects that they are unable to digest. Upon approaching a length of nearly 4 metres (13 ft), great white sharks begin to target predominately
marine mammalMarine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
s for food. 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
FarallonsThe Farallon Islands, or Farallones , are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, USA. They lie outside the Golden Gate and south of Point Reyes, and are visible from the mainland on clear days...
. The sharks attacked all three baits but rejected the sheep carcass.
Great white sharks' reputation as ferocious predators is well-earned, yet they are not (as was once believed) indiscriminate "eating machines". They are ambush hunters, taking prey by surprise from below. Near the now famous Seal Island, in South Africa's
False BayFalse Bay is a body of water defined by Cape Hangklip and the Cape Peninsula in the extreme South-West of South Africa.- Description and location :...
, shark attacks most often occur in the morning, within 2 hours after sunrise, when visibility is poor. Their success rate is 55% in the first 2 hours, falling to 40% in late morning after which hunting stops.
Hunting techniques vary by prey species. Off Seal Island the shark ambush brown fur seals from below at high speeds, hitting the seal mid-body. They go so fast that they can completely leave the water. The peak burst speed of these sharks is largely accepted in the scientific community to be above 40 kilometres per hour (24.9 mph). However further precision is still speculative. They have also been observed chasing prey after a missed attack. Prey is usually attacked at the surface.
Off California, sharks immobilize
northern elephant sealThe northern elephant seal is one of two species of elephant seal . It is a member of the family Phocidae . 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...
s 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 can be as large or larger than the hunter and are potentially dangerous adversaries. Prey is normally attacked sub-surface. Harbour seals are simply grabbed from the surface and pulled down until they stop struggling. They are then eaten near the bottom.
California sea lionThe California sea lion is a coastal sea lion of western North America. Their numbers are abundant , and the population continues to expand about 5% annually. They are quite intelligent and can adapt to man-made environments...
s are ambushed from below and struck mid-body before being dragged and eaten.
White sharks attack dolphins and porpoises from above, behind or below to avoid being detected by their echolocation. Targeted species include
dusky dolphinThe dusky dolphin is a dolphin found in coastal waters in the Southern Hemisphere. Its specific epithet is Latin for "dark" or "dim". It is very closely genetically related to the Pacific white-sided dolphin, but current scientific consensus is that they are distinct species...
s,
Risso's dolphinRisso's dolphin is the only species of dolphin in the genus Grampus.-Taxonomy:Risso's dolphin is named after Antoine Risso, whose description formed the basis of the first public description of the animal, by Georges Cuvier, in 1812...
s,
bottlenose dolphinBottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one...
s,
Humpback dolphinHumpback dolphins are members of the genus Sousa. These dolphins are characterized by the conspicuous humps and elongated dorsal fins found on the back of adult members of the species...
s,
harbour porpoiseThe harbour porpoise is one of six species of porpoise. It is one of the smallest marine mammals. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen...
s, and
Dall's porpoiseDall's porpoise is a species of porpoise found on the North Pacific. It came to worldwide attention in the 1970s when it was disclosed for the first time to the public that salmon fishing trawls were killing a lot, thousands of Dall's porpoises and other cetaceans each year by accidentally...
s. Close encounters between dolphins and predatory sharks often result in evasive responses by the dolphins. However, in rare cases, a group of dolphins may chase a single predatory shark away in an act of defense. White shark predation on some species of whales have also been observed. White sharks often attack and prey upon
pygmy sperm whaleThe Pygmy Sperm Whale is one of three species of toothed whale in the sperm whale family. They are not often sighted at sea, and most of what is known about them comes from the examination of stranded specimens.-Taxonomy:...
s,
Kogia breviceps, in the
Mediterranean SeaThe Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. In addition, white sharks also attack and prey upon
beaked whaleBeaked whales are 21 species of toothed whales, members of the family Ziphiidae, are notable for their elongated beaks. Beaked whales are one of the world's most extreme divers. They can dive for long periods—20 to 30 minutes is common, and 85 minute dives have been recorded—and to...
s.
Even though the great whites are known to generally avoid conflicts with each other, the phenomenon of
cannibalismIn zoology, cannibalism is the act of one individual of a species consuming all or part of another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded for more than 1500 species...
is not alien to this species. Large individuals may aggressively interact intraspecifically with small individuals. A 3 m (9.8 ft) long great white shark was nearly bitten into two by a reportedly 6 m (19.7 ft) long great white shark in Stradbroke Island, near Brisbane in Australia.
White sharks also scavenge on whale carcasses. In one such documented incident, white sharks were observed scavenging on a whale carcass alongside tiger sharks.
Reproduction
Little is known about great white shark behavior in the way of
matingIn biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
habits. Birth has never been observed, but pregnant females have been examined. Great white sharks are
ovoviviparousOvoviviparity, ovovivipary, or ovivipary, is a mode of reproduction in animals in which embryos develop inside eggs that are retained within the mother's body until they are ready to hatch...
(eggs develop and hatch in the uterus and continue to develop until birth). 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 intrauterine cannibalism; stronger pups consume their weaker womb-mates. Delivery is in spring and summer.
Almost nothing is known about mating behavior. Some evidence points to the near-soporific effect of a large feast (such as a whale carcass) possibly inducing mating.
Great white sharks reach sexual maturity at around 15 years of age. Maximum life span is believed to be more than 30 years (see references).
Natural threats
Although the great white is typically regarded as an
apex predatorApex predators are predators that have no predators of their own, residing at the top of their food chain. Zoologists define predation as the killing and consumption of another organism...
in the wild, it is in rare cases preyed upon by the larger orca (also known as a killer whale). Interspecific competition between the great white shark and the orca is probable in regions where dietary preferences of both species may overlap. An incident was documented on October 4, 1997, in the
Farallon IslandsThe Farallon Islands, or Farallones , are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, USA. They lie outside the Golden Gate and south of Point Reyes, and are visible from the mainland on clear days...
off
CaliforniaCalifornia is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. An estimated 4.7 – female orca immobilized an estimated 3 – great white shark. The orca held the shark upside down to induce the
tonic immobilityApparent death, colloquially known as playing dead or playing possum, is an antipredator behavior observed in a wide range of animals in which they take on the appearance of being dead to an observer...
and kept the shark still for fifteen minutes, causing it to suffocate and then proceeded to eat the dead shark's liver. Another similar attack apparently occurred there in 2000, but its outcome is not clear. After both attacks, the local population of about 100 great whites vanished. Following the 2000 incident, a great white with a satellite tag was found to have immediately submerged to depth of 500 m and swum to
HawaiiHawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
.
During prehistoric times, other large toothed whales, such as
SqualodonSqualodon is an extinct genus of whales, belonging to the family Squalodontidae. Named by Grateloup in 1840, it was originally believed to be an iguanodontid dinosaur but has since been reclassified. The name Squalodon comes from Squalus, a genus of shark...
and
DorudonDorudon was a genus of ancient cetacean that lived alongside Basilosaurus 41 to 33 million years ago, in the Eocene. They were about five meters long and were most likely carnivorous, feeding on small fish and mollusks. Dorudontines lived in warm seas around the world...
may have also preyed on great white sharks. These whales, in turn, were likely preyed on by the much larger lamnid shark
C. megalodonThe megalodon and ὀδούς ) is an extinct species of shark that lived roughly from 28 to 1.5 million years ago, during the Cenozoic Era .The taxonomic assignment of C...
.
Breaching behaviour
A breach is the result of a high speed approach to the surface with the resulting momentum taking the shark partially or completely clear of the water. This is a hunting technique employed by great white sharks whilst hunting seals. This behavior most often takes place on cape fur seals at Seal Island in False Bay, South Africa, and was first documented by photographer
Chris FallowsAfrican born Chris Fallows is an expert on the Great White Shark and their hunting habits. He has amassed the largest database of predatory events involving Great White Sharks in False Bay and was the first member of the scientific community to observe the breaching behaviour.-Early life:Growing up...
. Here, in the region of 600 natural predatory events are recorded annually between April and September each year. The seals swim on the surface and the great white sharks launch their predatory attack from the deeper water below. They can reach speeds of up to 40 miles per hour and can at times launch themselves more than 10 feet in the air. Data recorded shows that the sharks are successful in just under 50% of all these natural predatory events. In 2011, a 3-metre long shark jumped onto a 7-person
research vesselA research vessel is a ship designed and equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel, others require a dedicated vessel...
off Seal Island. The crew were undertaking a population study using sardines as bait, and the incident was judged to be an accident.
Shark attacks
More than any documented attack,
Peter BenchleyPeter Bradford Benchley was an American author, best known for his novel Jaws and its subsequent film adaptation, the latter co-written by Benchley and directed by Steven Spielberg...
's best selling novel
JawsJaws is a 1974 novel by Peter Benchley. It tells the story of a great white shark that preys upon a small resort town, and the voyage of three men to kill it....
and the subsequent
1975 film adaptationJaws is a 1975 American horror-thriller film directed by Steven Spielberg and based on Peter Benchley's novel of the same name. In the story, the police chief of Amity Island, a fictional summer resort town, tries to protect beachgoers from a giant man-eating great white shark by closing the beach,...
directed by
Steven SpielbergSteven Allan Spielberg KBE is an American film director, screenwriter, producer, video game designer, and studio entrepreneur. In a career of more than four decades, Spielberg's films have covered many themes and genres. Spielberg's early science-fiction and adventure films were seen as an...
provided the great white shark with the image of a "man eater" in the public mind. While great white sharks have killed humans, they typically do not target them: for example, in the
Mediterranean SeaThe Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
there have been 31 confirmed attacks against humans in the last two centuries, most non-fatal. Many incidents seem to be "test-bites". Great white sharks also test-bite
buoyA buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...
s, flotsam, and other unfamiliar objects, and might grab a human or a
surfboardA surfboard is an elongated platform used in the sport of surfing. Surfboards are relatively light, but are strong enough to support an individual standing on them while riding a breaking wave...
to identify it.
Other incidents seem to be cases of mistaken identity, in which a shark ambushes a bather or surfer from below, believing the silhouette is from a seal. Many attacks occur in waters with low visibility or other situations which impair the shark's senses. The species appears to not like the taste of humans, or at least finds the taste unfamiliar. Further research shows that they can tell in one bite whether or not the object is worth attacking. Humans, for the most part, are too bony for their liking. They much prefer a fat, protein-rich seal.
However, some researchers have hypothesized that the reason the proportion of fatalities is low is not because sharks do not like human flesh, but because humans are often able to escape after the first bite. In the 1980s John McCosker noted that divers who dove solo and were attacked by great whites were generally at least partially consumed, while divers who followed the buddy system were generally rescued by their buddy. Tricas and McCosker suggest that a standard pattern for great whites is to make an initial devastating attack, and then wait for the prey to weaken before consuming the wounded animal. Humans' ability to move out of reach with the help of others, thus foiling the attack, is unusual for a great white's prey.
Humans, in any case, are not appropriate prey because the shark's digestion is too slow to cope with a human's high ratio of bone to muscle and fat. Accordingly, in most recorded attacks, great whites broke off contact after the first bite. Fatalities are usually caused by blood loss from the initial bite rather than from critical organ loss or from whole consumption. Since the year 2000 there have been a total of 66 unprovoked great white shark attacks, with only 14 of these attacks being fatal.
A shark conservationist, Jimmy Hall, reported and documented his personal encounter with a very large great white shark, nicknamed Schatzi, in December, 2005, in waters off
HawaiiHawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
. This encounter received worldwide attention as it remained entirely peaceful. J. Hall was first cautious but later on swam with this shark without cage protection and touched it repeatedly while filming it simultaneously.
Attacks on boats
Great white sharks infrequently attack and sometimes even sink boats. Only 5 of the 108 authenticated unprovoked shark attacks reported from the Pacific Coast during the 20th century involved
kayakA kayak is a small, relatively narrow, human-powered boat primarily designed to be manually propelled by means of a double blade paddle.The traditional kayak has a covered deck and one or more cockpits, each seating one paddler...
ers. In a few cases they have attacked boats up to 10 metres (32.8 ft) in length. They have bumped or knocked people overboard, usually attacking the boat from the stern. In one case in 1936, a large shark leapt completely into the
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
n fishing boat
Lucky Jim, knocking a crewman into the sea. Tricas and McCosker's underwater observations suggest that sharks are attracted to boats due to the electrical fields they generate.
Great white sharks in captivity
Prior to August, 1981, no great white shark in captivity lived longer than 11 days. In August, 1981, a shark survived for 16 days at
SeaWorldSeaWorld is a United States chain of marine mammal parks, oceanariums, and animal theme parks owned by SeaWorld Parks & Entertainment. The parks feature captive orca, sea lion, and dolphin shows and zoological displays featuring various other marine animals. There are operations in Orlando,...
San Diego before being released. The idea of containing a live great white at
SeaWorldSeaWorld is a United States chain of marine mammal parks, oceanariums, and animal theme parks owned by SeaWorld Parks & Entertainment. The parks feature captive orca, sea lion, and dolphin shows and zoological displays featuring various other marine animals. There are operations in Orlando,...
OrlandoOrlando is a city in the central region of the U.S. state of Florida. It is the county seat of Orange County, and the center of the Greater Orlando metropolitan area. According to the 2010 US Census, the city had a population of 238,300, making Orlando the 79th largest city in the United States...
was used in the 1983 film
Jaws 3-DJaws 3-D is a 1983 thriller film directed by Joe Alves and starring Dennis Quaid, Bess Armstrong, Lea Thompson and Louis Gossett, Jr...
.
In 1984, shortly before its opening day, the
Monterey Bay AquariumThe Monterey Bay Aquarium is located on the former site of a sardine cannery on Cannery Row of the Pacific Ocean shoreline in Monterey, California. It has an annual attendance of 1.8 million visitors. It holds thousands of plants and animals, representing 623 separate named species on display...
in
Monterey, CaliforniaThe City of Monterey in Monterey County is located on Monterey Bay along the Pacific coast in Central California. Monterey lies at an elevation of 26 feet above sea level. As of the 2010 census, the city population was 27,810. Monterey is of historical importance because it was the capital of...
, housed its first great white shark which died after 10 days. In July 2003, Monterey researchers captured a small female and kept it in a large netted pen near
Malibu for five days. They had the rare success of getting the shark to feed in captivity before its release. Not until September, 2004, was the aquarium able to place a great white on long-term exhibit. A young female, which was caught off the coast of
VenturaVentura is the county seat of Ventura County, California, United States, incorporated in 1866. The population was 106,433 at the 2010 census, up from 100,916 at the 2000 census. Ventura is accessible via U.S...
, was kept in the aquarium's massive 3800000 litres (1,003,853.7 US gal) Outer Bay exhibit for 198 days before she was released in March, 2005. She was tracked for 30 days after release. On the evening of August 31, 2006, the aquarium introduced a juvenile male caught outside
Santa Monica BaySanta Monica Bay is a bight of the Pacific Ocean in southern California, United States. Its boundaries are slightly ambiguous, but it is generally considered to be the part of the Pacific within an imaginary line drawn between Point Dume, in Malibu, and the Palos Verdes Peninsula. Its eastern...
His first meal as a captive was a large
salmonSalmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
steak on September 8, 2006, and as of that date, he was estimated to be 1.72 metres (67.7 in) in length and to weigh approximately 47 kilograms (103.6 lb). He was released on January 16, 2007, after 137 days in captivity.
In addition, Monterey Bay Aquarium housed a third great white, a juvenile male, for 162 days between August 27, 2007, and February 5, 2008. On arrival, he was 1.4 metres (4.6 ft) long and weighed 30.6 kilograms (67.5 lb). He grew to 1.8 metres (5.9 ft) and 64 kilograms (141.1 lb) before release. A juvenile female came to the Outer Bay Exhibit on August 27, 2008. While she swam well, the shark fed only one time during her stay and was tagged and released on September 7. Another juvenile female was captured near Malibu on August 12, 2009, introduced to the Outer Bay exhibit on August 26, and successfully released to the wild on November 4, 2009.. Monterey Bay Aquarium recently added a four foot, seven inch male into their redesigned "Open Sea" exhibit on August 31, 2011. The animal was harvested in the waters off of Malibu.
Probably the most famous captive was a 2.4 metres (7.9 ft) female named Sandy, which in August of 1980 became the only great white to be housed at the
California Academy of SciencesThe California Academy of Sciences is among the largest museums of natural history in the world. The academy began in 1853 as a learned society and still carries out a large amount of original research, with exhibits and education becoming significant endeavors of the museum during the twentieth...
' Steinhart Aquarium in
San Francisco, CaliforniaSan Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...
. She was released because she would not eat and constantly bumped against the walls.
Shark tourism
Their infamous reputation gives sharks great appeal for tourists. While it is safe to dive near sharks of most species, diving with great whites requires great care. One common approach is for divers to stay within a steel cage.
Cage diving is most common off the coasts of
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
,
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, and
Guadalupe IslandGuadalupe Island, or Isla Guadalupe is a volcanic island located 241 kilometers off the west coast of Mexico's Baja California peninsula and some 400 kilometers southwest of the city of Ensenada in Baja California state, in the Pacific Ocean...
off the coast of Baja, California, where great whites frequent. Cage diving and swimming with sharks is a focus for a booming tourist industry due to its popularity. A common practice is to
chumChumming is the practice of luring animals, usually fish or sharks, by throwing "chum" into the water. Chum often consists of fish parts and blood, which attract fish, particularly sharks due to their keen sense of smell....
the water with pieces of fish to attract sharks. These practices may make sharks more accustomed to people in their environment and to associate human activity with food - a potentially dangerous situation. By drawing bait on a wire towards the cage, tour operators lure the shark to the cage, possibly striking it, exacerbating this problem. Other operators draw the bait away from the cage, causing the shark to swim past the divers.
At present, hang baits are illegal off Isla Guadalupe and reputable dive operators do not use them. Operators in South Africa and Australia continue to use hang baits and pinniped decoys.
Companies object to being blamed for shark attacks, pointing out that lightning tends to strike humans more often than sharks bite humans. Their position is that further research needs to be done before banning practices such as chumming, which may alter natural behavior.. One compromise is to only use chum in areas where whites actively patrol anyway, well away from human leisure areas. Also, responsible dive operators do not feed sharks. Only sharks that are willing to scavenge follow the chum trail and if they find no food at the end then the shark soon swims off and does not associate chum with a meal. It has been suggested that government licensing strategies may help enforce these suggested advisories.
The shark tourist industry has some financial leverage in conserving this animal. A single set of great white jaws can fetch a one-time price of up to £20,000. However, that is a fraction of the tourism value of a live shark, a more sustainable economic activity. For example, the dive industry in Gansbaai,
South AfricaThe Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, consists of six boat operators with each boat guiding 30 people each day. With fees between £50 to £150 per person, a single live shark that visits each boat can create anywhere between £9,000 and £27,000 of revenue daily.
Conservation status
It is unclear how much a concurrent increase in fishing for great white sharks has caused the decline of great white shark populations from the 1970s to the present. No accurate population numbers are available, but the great white shark is now considered endangered. Sharks taken during the long interval between birth and sexual maturity never reproduce, preventing population recovery.
The IUCN notes that very little is known about the actual status of the great white shark, but as it appears uncommon compared to other widely distributed species, it is considered
vulnerableOn 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
. It is included in Appendix II of CITES, meaning that international trade in the species requires a permit.
Fishermen target many sharks for their jaws, teeth, and fins, and as game fish in general. The great white shark, however, is rarely an object of commercial fishing, although its flesh is considered valuable. If casually captured (it happens for example in some tonnare in the Mediterranean), it is misleadingly sold as
smooth-hound shark.
As of April, 2007, great white sharks were fully protected within 370 kilometres (199.8 nmi) of
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
and additionally from fishing by New Zealand-flagged boats outside this range. The maximum penalty is a $250,000 fine and up to six months in prison.
News and articles
Photographic depictions and tagging activities
Videos