One of the most frequently asked questions during our tour is: what do they eat? Yes, everyone can imagine they eat fish, fur seals and sea lions…. but let’s discuss a bit more about the Great White Shark Diet.
Fat is the key for great white sharks diet
Like some of us, the great white prefers a fatty meal to one with lots of protein. That’s why its main prey item is the pinniped, an aquatic carnivore like a seal or a sea lion. Generally, humans are too muscular and lean for a typical shark meal, but a seal or sea lions might be 50 percent fat, representing a very efficient meal for great whites [source: Carey]. They’ll also dine on other fishes and occasionally sea turtles. The great white shark consumes approximately 11 tons of food in one year (for comparison’s sake, a 150-pound (68-kilogram) human being wolfs down about half a ton) [source: Parker].
Great White Sharks are ambush predator
When Great White Sharks hunt, the prey is usually hunted by ambush. The shark swims under the surface until it’s just a few feet away from its prey. Then it attacks quickly, moving its head up to the surface to grab the unlucky victim. , where the shark will attempt to rush the animal by surprise and inflict a sudden and massive fatal bite. Often this initial rush is so strong that the intense impact may send the prey out of the water or will send the shark into the air if it misses the target. (This kind of breaching behaviour is more often in South Africa. Depend on our shark trip experience, it rarely happens in South Australia water).
The sharks will retire and wait for the prey too quickly die, giving rise to the terms bite and spit or bite and wait for this method of attack. White sharks are also opportunistic scavengers and will feed on the carcasses of whales and basking sharks; however, they are not indiscriminate. Referred from Britannica.
Size of shark and prey will make a difference in diet
What Great White Sharks eat also depends on their size and age. Generally, when Great White Sharks are young, they feed on smaller prey, like fish and rays. As they grow larger, they feed more exclusively on marine mammals, such as sea lions, seals and small whales. Referred from UC Berkeley, large white sharks will also scavenge on the carcasses of whale sharks, and on the fat-rich blubber layer of dead whales. They will occasionally feed on sea turtles and sea otters, and are known to attack, but not eat, humans.
Great White Sharks in Australia
A Great White Shark study from The University of Sydney indicates the young sharks’ diet in NSW water. Dr Vic Peddemors a co-author from the NSW Department of Primary Industries (Fisheries), said: “We discovered that although mid-water fish, especially eastern Australian salmon, were the predominant prey for juvenile white sharks in NSW, stomach contents highlighted that these sharks also feed at or near the seabed.”
The study found that based on abundance, the sharks’ diet relied mostly on:
- Pelagic, or mid-water ocean swimming fish, such as Australian salmon: 32.2%
- Bottom-dwelling fish, such as stargazers, sole or flathead: 17.4%
- Reef fish, such as eastern blue gropers: 5.0%
- Batoid fish, such as stingrays: 14.9%
Referred from Department of Environment Issues Paper of the White Shark, the white shark does not feed continually and a large meal such as a seal may last a medium-sized shark as long as a week (Bruce, 1995), although the overall frequency at which they feed is likely dependent on the type of prey being targeted (Semmens et al, 2013). In some areas (e.g. South Australia), large white sharks will feed on fur seals and Australian sea lions at colonies for brief periods and then move into other habitats where they switch to targeting elasmobranchs and finfish species such as snapper (Pagrus auratus) (Bruce et al., 2006; Semmens et al, 2013).
The way Adventure Bay Charters work with Great White Sharks
As the Department of Environment mentioned, shark-based tourism activities could offer significant opportunities for on-going access to and research on white sharks and opportunities for public education.
Every year we take thousands of customers from all over the world to the natural habitats of White Sharks and trying to show them the natural behaviour of these amazing species.
The study from Brucce & Bradford recommended reducing the exposure of sharks to berleying and bait; ongoing monitoring of shark behaviour at the islands to establish the effectiveness of any management response and an education program aimed at clients and operators of shark cage diving ventures informing them of how the industry is managed, why the management is important and how the impacts on sharks and the environment from industry activities is minimised and regulated.
As an advanced ecotourism and bait & burley free operator, we care about white sharks and always try our best to minimise our impact to them, especially in our Bottom Cage Dive experience. We are giving people a unique opportunity to go into the shark territory without disturbing them, as we are not using any attractions from Bottom Cage.