"This fits with a lot of other research we've done showing that wild animals, including predators, select diets precisely balanced to meet their nutrient needs," said co-author Professor David Raubenheimer, Chair of Nutritional Ecology in the School of Life and Environmental Sciences.
The scientists also found that larger sharks tended to have a diet that was higher in fat, likely due to their high energy needs for migration.
"The hunting of bigger prey, including other sharks and marine mammals such as dolphin, is not likely to happen until the sharks reach about 2.2 meters in length," Mr Grainger said. Mr Grainger said that marine mammals, other sharks and cephalopods (squid and cuttlefish) were eaten less frequently. The remainder was unidentified fish or less abundant prey. Credit: Ryan Montgomery/Aerologistics Helicopters Great white shark swimming of east Australian coast taken from a helicopter. The scientists compared this with published data elsewhere in the world, mainly South Africa, to establish a nutritional framework for the species. The study examined the stomach contents of 40 juvenile white sharks (Carcharodon carcharias) caught in the NSW Shark Meshing Program.
Mr Grainger said: "This evidence matches data we have from tagging white sharks that shows them spending a lot of time many meters below the surface." 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, published today on World Oceans Day in the journal Frontiers in Marine Science, is an important contribution towards understanding the sharks' feeding and migratory habits.ĭr. "The stereotype of a shark's dorsal fin above the surface as it hunts is probably not a very accurate picture," he said.
candidate at the Charles Perkins Centre and School of Life and Environmental Sciences at the University of Sydney. This indicates the sharks must spend a good portion of their time foraging just above the seabed," said lead author Richard Grainger, a Ph.D. "Within the sharks' stomachs we found remains from a variety of fish species that typically live on the seafloor or buried in the sand.
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