Marine Creature: Great White Shark
Kindly compiled by Sarah Titley, Project Manager for Shark Spotters
English: Great White Shark, White Shark, Blue Pointer
Afrikaans: Withaai, Witdoodshaai.
Scientific Name: Carcharodon carcharias
Great White Sharks are the largest predatory fish in the sea. Their dorsal surface (upper body) ranges from dark grey to light brown, while the ventral side (belly) is white. Its counter-current heat exchange system enables the great white to keep vital organs at up to 14°C warmer than the surrounding water. It can reach close to 50 km per hour in short bursts, but in long distance, such as during ocean crossings, they move at a minimum sustained speed of up to 5 km per hour. The Great White Shark have an enormous liver that can weigh up to 24 percent of its entire weight.
Great White Sharks try to avoid fighting for food. When there is only enough food for one, they have a tail-slapping contest. The sharks swim past each other, each slapping the surface of the water with their tails, and often directing the spray toward the other shark. The one who gets the meal is the shark that delivers the most tail slaps.
- Lifespan: Estimated at 25-30 years
- Size: Up to 6 m in length, weighing up to 2 tons.
- Food: Cape fur seals, other sharks, rays, bony fish, dolphins, whales.
White sharks occur in one of the widest habitat and geographic ranges of any fish. Great White sharks live along the coasts of all continents except Antarctica. They are widely distributed around the South African coast (as well as the world’s oceans) with the highest concentrations occurring in temperate waters particularly in the vicinity of Cape fur seal colonies.
Great White Sharks breed late in life. They do not start breeding until they’re at least twenty years old. Males are believed to reach sexual maturity at 9 to 12 years of age when they are about 4 metres in length. Females reach maturity at a larger size of between 4 and 5 metres at 13 to 16 years old. Embryos mature inside the mother’s uterus, at first nourished by a yolk sac and later through unfertilized eggs. The gestation period is around 14-18 months and the female gives birth to live young estimated to be between 1 and 1,5 metres long.
Great White Sharks rarely attack people and when they do, it is because they mistaken the person for their usual seal prey. Great Whites often have scratches and scars on their snouts which resulted from their prey fighting back. Scientists estimate that after a big meal, a Great White Shark can last up to three months before needing another one. A Great White Shark can roll its eyeballs back, which protects the vital front part of the eye from being scratched.
Feeding & Hunting
26 broad triangular shaped and serrated teeth in each row of the upper jaw and 24 more pointy teeth in the lower jaw rows. A Great White Shark may use and lose more than one thousand teeth in its life time. A Great White Shark is capable of eating sea lions whole. In one year, a single Great White consumes about 11 tons of food.
Threats from humans
Threats to the species include targeted commercial and sports fisheries for jaws, fins, game records and for aquarium display; protective beach meshing; media-fanned campaigns to kill Great White Sharks after a biting incident occurs; and degradation of inshore habitats used as pupping and nursery grounds.
Conservation Status & International Protection
The great white is fully protected in seven countries, including South Africa. Some scientists believe there are less than 10,000 Great White Sharks in the entire world. Class under the IUCN Red List classification as Vulnerable. For more information visit IUCN Red List
Best places in the world to see these creatures:
Cape Town and Port Elizabeth, South Africa
South-East coast, Australia
Profile: Shark Spotters
The primary funders of the Shark Spotting Program are City of Cape Town (local government) and Save Our Seas Foundation. The programme also relies on public donations and fundraising events.
Description/Background of work
Shark Spotters is a pioneering shark safety programme that has attracted international and local attention because of the novel way it seeks to find a solution to potential conflicts between sharks and people. Adopted by the City of Cape Town in 2005 in response to a spate of shark bite incidents and increased shark sightings, Shark Spotting is now the primary shark safety programme used in Cape Town.
Shark Spotters improves beach safety through both shark warnings and emergency assistance in the event of a shark incident. It contributes to research on shark ecology and behaviour, raises public awareness about shark-related issues, and provides employment opportunities and skills development for Shark Spotters.
Shark spotters are positioned at strategic points along the Cape Peninsula, primarily along the False Bay Coastline. A highly trained spotter is placed on the mountain with polarised glasses and binoculars and is in radio contact with another spotter on the beach. When a shark is sighted the siren is sounded and water users are asked to leave the water. A protocol using four informational flags communicates the spotting conditions and presence/absence of sharks to the public.