Great white sharks sink as deep as 108 metres into the ocean and swim back to the surface to save energy when hunting for seals, according to a study by Australian and international researchers.
These "behavioural strategies" help sharks to maximize their energy and allow them to increase encounter rates with fast-swimming seals, according to the study published in The Company of Biologists journal on Tuesday.
The study said the method is similar to "sitting and waiting" for prey to approach them, rather than swimming long distances fast to hunt.
The sharks exhibited a series of energy-efficient gliding behaviours during descending phases of dives followed by active ascents.
The behaviour is more efficient than horizontal surface swimming, which requires more energy, the study said.
Information about adult white sharks, which are 5 to 6 metres long and weigh more than 2 tons, has been elusive as they are hard to track.
The study was conducted by attaching accelerometers and video cameras to 10 great white sharks to see how they used energy when hunting for long-nosed fur seals off the Neptune Islands, South Australia, which is popular with tourists keen to dive with the predators.
