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 Twentieth Century involved kayakers.^[30] In a few cases they have attacked boats up to 10 metres (33 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 African 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.^[31]

reat white sharks are carnivorous, and primarily eat fish (including rays, tuna, and smaller sharks), dolphins, porpoises, whale carcasses and pinnipeds such as seals, fur seals and sea lions and sometimes sea turtles. Sea otters and penguins are attacked at times although rarely, if ever, eaten. Great whites have also been known to eat objects that they are unable to digest. In great white sharks above 3.41 metres (11 ft) a diet consisting of a higher proportion of mammals has been observed.^[16] These sharks prefer prey with high contents 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 to his boat in the South Farallons. The sharks attacked all three baits but rejected the sheep carcass.^[17]

The great white is regarded as an apex predator with its only real threats from humans. Although their diets overlap greatly, great whites do not seem to directly compete with orcas and there are few reports of encounters between them. The average orca is larger and faster which is probably why the sharks do not bother to compete. However in one famous incident a female orca killed a subadult great white and her calf feasted on the shark's liver.^[18] Pods of dolphins can kill a great white shark through mobbing behaviour in which the dolphins ram the shark. Great whites are also sometimes preyed on by larger specimens.

Great white breaching to catch a Cape Fur Seal

Great white sharks' reputation as ferocious predators is well-earned, yet they are not (as was once believed) indiscriminate "eating machines". They typically hunt using an "ambush" technique, taking their prey by surprise from below. Near the now-famous Seal Island, in South Africa's False Bay; studies have shown that the shark attacks most often occur in the morning, within 2 hours after sunrise. The reason for this is that it is hard to see a shark close to the bottom at this time. The success rate of attacks is 55% in the first 2 hours, it falls to 40% in late morning and after that the sharks stop hunting.^[19]

The hunting technique of the white shark varies with the species it hunts. When hunting Cape fur seals off Seal Island, South Africa, the shark will ambush it from below at high speeds and hit the seal at mid-body. They go so fast that they actually breach out of the water. The peak burst speed of these sharks is largely accepted in the scientific community to be above at least 40 kilometers per hour (25 mi/h), however further precision is still regarded as speculation and obviously depends on the individual shark. ^[20] They have also been observed chasing their prey after a missed attack. The prey is usually attacked at the surface.[

shark work

Great white sharks live in almost all coastal and offshore waters which have a water temperature of between 12 °C (54 °F) and 24 °C (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, Adriatic Seas and New Zealand ^[5], where they are a protected species. 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 sometimes found in tropical waters like those of the Caribbean, and has been recorded off Mauritius, Madagascar, Kenya and the Seychelles.^[6] 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 known as White Shark Café, 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 at their destination; it might be seasonal feeding or possibly a mating area.^[7]

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.^[8]