Great White Shark

Great white sharks live in temperate and subtropical coastal waters, mostly where the water is between about 12 and 24 degrees. They can turn up in almost any ocean, but they are seen regularly in only a handful of places, all of them with seal or sea lion colonies that provide reliable prey: the Western Cape and Mossel Bay in South Africa, the Neptune Islands and the south coast of Australia, Stewart Island and the Chatham Islands in New Zealand, the Farallon Islands and the coast of California, Guadalupe Island off Mexico, and the northwest Atlantic from Cape Cod and Long Island to Nova Scotia. Elsewhere, from the Mediterranean, where scientists call the small remaining population a ghost because it is so rarely seen, to Japan, Chile or Argentina, records are scattered and years apart. Satellite tags show that they travel widely: some cross the Indian Ocean between South Africa and Australia, and others spend months in the open Pacific, in an area nicknamed the white shark café.

Most adult great whites measure between 3.5 and 5 meters and weigh from 500 kilograms to more than a ton. Females grow much larger than males, and the biggest reliably measured were close to 6 meters; reports of 7 or 8 meter sharks circulate widely, but none has been verified. Even a newborn pup is about 1.2 to 1.5 meters long, one of the largest sizes at birth of any fish. The mouth holds about 300 serrated, triangular teeth in several rows, and new teeth move forward to replace those that break or fall out. Great whites usually cruise slowly, at a few kilometers per hour, to save energy, but they can burst to around 40 kilometers per hour when they attack, fast enough to launch their whole body out of the water when they strike a seal from below. Their warm muscles, kept several degrees above the temperature of the sea, give them the power for those sprints even in cold water.

Diet changes dramatically with age. Young great whites feed mostly on fish, rays and smaller sharks, since their jaws and teeth are not yet built for large prey. Once they pass around three meters, the teeth broaden and marine mammals enter the menu: seals, sea lions and dolphins, along with the occasional whale carcass, which can draw several sharks to feed together. The classic hunting technique is a vertical ambush from below, using the dark back as camouflage against the seabed, ending in a strike so fast that the animal sometimes leaves the water entirely. Timing matters too. At Seal Island in South Africa's False Bay, studies of thousands of attacks found that the sharks are most successful in the first hour or two after sunrise, when the light is low and young fur seals are heading out to sea. Great whites are opportunists rather than constant hunters, and a large meal of fat rich blubber can sustain an adult for days or even weeks before it needs to feed again.

Great whites are mostly solitary but not asocial. Where several gather at a seal colony, they establish a loose hierarchy based on size, and confrontations are usually settled by posture and display rather than fighting. Photo identification shows that many individuals return to the same feeding sites year after year, which is how researchers have come to know some sharks by name. Their senses are extraordinary. They can smell blood and oil from a long distance, and pores on the snout full of jelly, called ampullae of Lorenzini, pick up the faint electrical fields produced by the muscles of other animals, which helps them find prey buried in sand or hidden in murky water. Now and then a shark lifts its head above the surface, a rarely seen behavior called spy hopping that seems to let it look around above the waves. Curiosity is a strong trait. Sharks often investigate unfamiliar objects with their mouths, which explains many encounters that get reported as attacks.

No animal has a reputation further from its actual behavior. The great white is involved in more recorded incidents with people than any other shark, yet the global total is only a handful each year and fatalities are rarer still. Most encounters appear to be exploratory bites that end when the shark disengages, since a human offers little of the fat content it seeks. Jaws, released in 1975, reshaped public perception and triggered decades of hostility toward the species, something its own author later regretted publicly. Today the relationship is shifting: cage diving in South Africa and Australia, and at Guadalupe Island until Mexico banned it in 2023 to protect the sharks, turned the species into an economic asset, and tagging programs have made it one of the best studied large predators in the sea.

Nobody knows how many great white sharks are left in the world. The often quoted figure of about 3,500 is only a rough guess, so scientists count regional populations instead: an Australian government study in 2018 estimated about 750 adults, and some 5,500 sharks in total, in the population of eastern Australia and New Zealand, and photo identification has counted a few hundred individuals each at the Farallon Islands and at Guadalupe Island. Off the northeastern United States numbers are recovering after decades of protection, while off South Africa sightings have dropped sharply since about 2017, partly because orcas began hunting great whites there. The IUCN lists the species as Vulnerable. Females mature at around 30 years and have few pups, so any population takes decades to recover. The main threats are accidental capture in fishing gear, fishing for jaws, teeth and fins, and shark control nets off beaches. Many countries, from South Africa to the United States, now protect it.