Great white sharks eat a surprisingly varied diet that shifts dramatically as they grow. Juveniles feed mostly on fish and rays, while adults increasingly target seals and sea lions. But at every life stage, these sharks are more opportunistic than their reputation as apex seal-hunters suggests.
What Young Great Whites Eat
For the first several years of life, great white sharks stick close to shore and eat relatively small prey. Studies of juvenile stomachs in southern California have found round stingrays, bat rays, and California halibut. Young whites also eat crabs, squid, and small bony fish like yellowfin croaker. These are all bottom-dwelling or nearshore species, reflecting where juvenile great whites spend most of their time.
A detailed dietary study of 40 juvenile great whites in Australia, published in Frontiers in Marine Science, found that bony fish made up about 72% of prey items by number. East Australian salmon, a mid-water schooling fish, was the single most important prey species for juveniles in New South Wales waters, accounting for roughly 32% of the diet by abundance. Bottom-dwelling fish like stargazers, sole, and flathead made up another 17%, while rays (stingrays and electric rays) contributed about 15%. Reef fish such as eastern blue gropers accounted for around 5%.
What surprised researchers at the University of Sydney was how much time juvenile whites spend feeding on or near the seafloor, not just in open water. Their diet included eels, whiting, mullet, and wrasses, painting a picture of a young predator that hunts across multiple ocean zones rather than specializing in one type of prey.
The Shift to Marine Mammals
As great whites grow past about 3 meters (roughly 10 feet), their diet begins tilting toward larger, fattier prey. Adult and subadult sharks aggregate near seal and sea lion colonies to hunt, a pattern documented in California, South Africa, and Australia. Their primary mammal targets include harbor seals, California sea lions, and elephant seals. In some regions, they also bite sea otters, though these attacks may be investigatory rather than true feeding events.
This dietary transition makes energetic sense. Marine mammal blubber is extraordinarily calorie-dense. A single 30-kilogram chunk of whale or seal blubber contains enough energy to sustain a large adult shark (around 940 kg) for approximately six weeks, based on older metabolic estimates. More recent research using tracking data suggests adult whites actually burn energy faster than previously thought, meaning they likely need to feed more often than that, but blubber remains the most efficient food source available to them.
Despite their fame as seal hunters, mammals don’t dominate the diet by sheer number of prey items. In the juvenile study mentioned above, mammals represented only about 2.5% of prey items by count. However, because individual mammals are so much larger than fish, they made up nearly 40% of the total prey mass consumed. Even for sharks that regularly eat seals, fish remain a consistent part of the diet throughout life.
Scavenging on Whale Carcasses
Great whites don’t limit themselves to live prey. They readily scavenge whale carcasses when the opportunity arises. Documented cases include whites feeding on dead sperm whales, humpback whales, and fin whales. Observations off the coast of New South Wales, Australia, showed white sharks using specific feeding techniques on carcasses: protruding their upper jaws outward, shaking their heads to tear off chunks of blubber, and rolling their eyes back for protection during bites.
Multiple sharks will feed on a single carcass with relatively little aggression toward each other, which is unusual for a species often portrayed as fiercely territorial. Both white and tiger sharks were observed feeding on the same whale carcasses without significant conflict. The sharks did avoid biting near the whale’s tail flukes and pectoral fins, likely because there’s less blubber in those areas and the tough tissue is harder to tear.
How They Hunt Live Prey
Great whites use different strategies depending on what they’re hunting. For fast-moving seals near the surface, they employ a dramatic technique called breaching: swimming upward at high speed from below, hitting the prey at the surface, and launching as high as 10 feet into the air. During these attacks, sharks can reach speeds of 40 miles per hour. Breaching is relatively rare, though, because it requires an enormous burst of energy. Sharks typically reserve it for situations where the element of surprise gives them a decisive advantage.
For bottom-dwelling prey like rays and flatfish, the hunting style is far less theatrical. Young sharks in particular cruise near the seafloor, using their electroreceptive organs to detect prey hiding in sand or mud. This kind of foraging looks nothing like the explosive seal attacks seen in nature documentaries, but it represents a much larger share of how most great whites actually feed day to day.
How Much a Great White Needs to Eat
A 428-kilogram (roughly 940-pound) great white shark needs to consume between 1.2% and 1.9% of its body weight daily, according to metabolic research published in Scientific Reports. That translates to roughly 5 to 8 kilograms of food per day, or the equivalent of about one medium-sized fish like a silver seabream, or roughly one-third of a fur seal pup. The shark’s total daily energy expenditure was estimated at 22 to 28 megajoules, depending on swimming speed.
These numbers are significantly higher than earlier estimates that suggested large sharks could go weeks between meals. The older calculations were based on resting metabolism, but tracking data shows great whites swim continuously and burn energy at a much higher rate than lab conditions would predict. While they can certainly survive periods without eating, they’re not the infrequent feeders scientists once assumed.
Regional Differences in Diet
What a great white eats depends heavily on where it lives. In South Africa, whites near Seal Island in False Bay are famous for their explosive attacks on Cape fur seals. In central California, they patrol near elephant seal rookeries at places like the Farallon Islands, with peak predation on harbor seals and sea lions occurring in late summer as sharks transit along the coast. In eastern Australia, juveniles rely heavily on mid-water schooling fish like Australian salmon, supplemented by bottom-dwelling species and rays.
These regional differences reflect local prey availability more than any inherent preference. Great whites are generalist predators that eat what’s abundant and accessible at their size. A juvenile in southern California eats bat rays and halibut because those species are plentiful in warm, shallow nursery waters. An adult patrolling a seal colony in South Africa eats fur seals because that’s the highest-calorie prey available. The underlying strategy is the same: maximize energy intake relative to the cost of catching prey.