White sharks eat three to four times more food than thought, according to a University of Tasmania-led study.
It had been believed a 30kg meal of blubber could sustain a one-tonne shark for 1½ months, but the latest research suggests that is only enough for between 12 and 15 days.
The researchers came to the figure by putting acoustic tags on a dozen white sharks at the Neptune Islands off South Australia and calculating their metabolic rate.
They worked out how much energy the sharks used and therefore how much food they needed. University of Tasmania senior research scientist Jayson Semmens, who was the lead author on the study, said the amount of food required by white sharks was equivalent to eating a weaned seal pup every three days.
"That's pretty regular . . . it's because they have a high metabolic rate and they need to keep that going," he said.
Young white sharks feed mostly on fish, including Australian salmon and snapper. It is only when they have grown to about 3.4m long they start to eat marine mammals.
Dr Semmens said the results meant the effects of removing white sharks from the ocean were greater than believed.
"They're keeping under control a lot more animals than we thought," he said. The paper was published on Tuesday in the journal Scientific Reports.
'They're keeping under control a lot more animals than we thought.'" Scientist *Jayson Semmens *