Great white shark (Carcharodon carcharias)
|Size||Length: up to 6.4 m (3)|
|Weight||up to 3,400 kg (2)|
The great white shark is classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix II of CITES (4).
The mighty great white shark (Carcharodon carcharias) is often mistakenly thought of as the most voracious predator of the seas, and even has a reputation as a ferocious man-eater, something that sadly has been hugely exaggerated by the media. Their powerful body is supported by a cartilaginous skeleton (as opposed to the bone skeleton of most other vertebrates), is streamlined for efficient movement through the water, and has a pointed snout (5), two large, sickle-shaped pectoral fins and a large triangular first dorsal fin (6). The mouth is armed with an array of sharply pointed, serrated teeth; indeed the generic name is derived from the Greek word carcharos for ragged and odon for tooth (7). These sharks are grey or bronze on the upper surface of the body and are white underneath (5). They have an acute sense of smell and are able to sense electric fields through sensors in the snout (7).
Great white sharks are found throughout the world's oceans mostly in temperate and sometimes warm waters but occasionally in cold environments (3). Recent scientific research using satellite tags has found that adults can undertake long return migrations across entire ocean basins and back, while juveniles stay closer to the shore, but can also undertake long-distance coastal migrations (8) (9).
The preferred habitats of the great white shark are coastal and offshore waters of the continental and insular shelves and offshore continental islands, but recent evidence suggests that adults are probably pelagic for much of the year, readily being found in oceanic waters from the surface to depths of 980 metres and possibly more (8) (9).
Despite its worldwide notoriety, very little is known about the natural ecology and behaviour of the great white shark. These sharks are usually solitary or occur in pairs, although it is apparently a social animal that can also be found in small aggregations of 10 or more, particularly around a carcass (3) (6). Females are ovoviviparous; the pups hatch from eggs retained within their mother's body, and she then gives birth to live young (10). Great white sharks are particularly slow-growing, late maturing and long-lived, with a small litter size and low reproductive capacity (8). Females do not reproduce until they reach about 4.5 to 5 metres in length, and litter sizes range from two to ten pups (8). The length of gestation is not known but estimated at between 12 and 18 months, and it is likely that these sharks only reproduce every two or three years (8) (11). After birth, there is no maternal care, and despite their large size, survival of young is thought to be low (8).
Great whites are at the top of the marine food chain, and these sharks are skilled predators. They feed predominately on fish but will also consume turtles, molluscs, and crustaceans, and are active hunters of small cetaceans such as dolphins and porpoises, and of other marine mammals such as seals and sea lions (12). Using their acute senses of smell, sound location and electroreception, weak and injured prey can be detected from a great distance (7). Efficient swimmers, sharks have a quick turn of speed and will attack rapidly before backing off whilst the prey becomes weakened; they are sometimes seen leaping clear of the water (6). Great white sharks, unlike most other fish, are able to maintain their body temperature higher than that of the surrounding water using a heat exchange system in their blood vessels (11).
These sharks are sparsely distributed and have slow reproduction rates, factors making the population particularly vulnerable and slow to recover from depleted numbers (2). Although the population size is difficult to assess, evidence suggests that numbers have declined in several areas by up to 90 percent over the last 40 to 100 years (8) (13). Sharks caught either accidentally as bycatch or deliberately targeted are sold for their flesh, skins, oil and fins for shark-fin soup (8). The teeth and jaws of great white sharks are particularly valuable; a recently recovered specimen was valued at US$ 50,000 (8). Game fishing has increased in popularity recently and the great white shark is something of a holy grail for enthusiasts due to its great size, powerful resistance to capture, and reputation as the most dangerous fish in the sea (3) (7). Unfortunately, its inquisitive nature and tendency to investigate human activities, as well as to scavenge from fishing gear, makes this shark vulnerable to capture (3). This species is often found close to human settlements and habitat degradation, depletion of prey species, negative attitudes towards the shark, and shark fences to protect bathers further affect population numbers (3) (8). The great white shark is viewed with fear throughout much of its range, making conservation efforts difficult to initiate, and unwarranted, media-fanned campaigns to kill great whites have even occasionally occurred, following shark attacks or in anticipation of such attacks (3) (8).
The great white shark is protected in South Africa, Namibia, Australia, the USA and Malta (8) (13). The recent surge of interest in shark dives and ecotourism, especially in South Africa, southern Australia, and Guadalupe Island, Mexico, may provide a substantial local income and an important method of education (12). With effective legislation and policing, this tourist trade may well be a vital method of saving the species despite the complex issues involved (12). Vital research into this misunderstood fish is being carried out in countries such as Australia, Mexico, New Zealand, South Africa and the USA (8), and the FAO (Food and Agriculture Organisation of the UN) has prepared an International Plan of Action for the Conservation and Management of Sharks (IPOA-SHARKS) (14). Indeed, recent scientific findings that great whites regularly undergo long-distance, trans-boundary movements only highlight the need for international protective measures, with national legislation being no guarantee of survival of the species (8). However, further information gained from ongoing studies into their movements and the specific habitats the sharks utilise will hopefully provide the basis for designing appropriate protection measures to aid the survival of this remarkable shark around the world.
For more information on the great white shark see:
The Shark Trust:
Wildlife Conservation Society:
Save Our Seas Foundation:
BBC Wildlife Finder:
Authenticated (24/07/2006) by Dr. Ramón Bonfil, specialist on sharks, fisheries, and great white shark ecology; and member of the IUCN/SSC Shark Specialist Group.
- Bycatch: in the fishing industry, the part of the catch made up of non-target species.
- Cetaceans: a group comprising all whale species; therefore including dolphins and porpoises.
- Crustaceans: diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
- Dorsal fin: in fish, the unpaired fin found on the back of the body.
- Gestation: the state of being pregnant; the period from conception to birth.
- Molluscs: a diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.
- Ovovivipary: method of reproduction whereby the egg shell is weakly formed and young hatch inside the mother; they are nourished by their yolk sac and then born.
- Pectoral fins: in fish, the pair of fins that are found one on each side of the body just behind the gills. They are generally used for balancing and braking.
- Pelagic: inhabiting the open oceans.
IUCN Red List (March, 2008)
- Compagno, L.J.V.C. (2001) Sharks of the World: An annotated and illustrated catalogue of shark species known to date - Volume 2 - Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). In: Bonfil, R. (Ed) FAO Species Catalogue for Fishery Purposes No. 1. Vol. 2. FAO, Rome.
Fishbase (July, 2002)
CITES (March, 2008)
Australian Museum (July, 2002)
- Burnie, D. (2001) Animal. Dorling Kindersley, London.
Great White.org (July, 2002)
Proposals for amendment of Appendices I and II (CITES) - Thirteenth meeting of the Conference of the Parties: Bangkok (Thailand), 2-14 October 2004 (June, 2006)
- Bonfil, R., Meÿer, M., Scholl, M.C., Johnson, R., O’Brien, S., Oosthuizen, H., Swanson, S., Kotze, D. and Paterson, M. (2005) Transoceanic Migration, Spatial Dynamics and Population Linkages of White Sharks. Science, 310: 100 - 103.
WCMC Species Sheets (March, 2008)
Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) (July, 2002)
Shark Trust (July, 2002)
- Bonfil, R. (2006) Pers. comm.
IPOA-SHARKS (March, 2008)