GoPro image of a great white shark taken off the coast at Evans Head, NSW. Photo: Richard Grainger
Dr Vic Peddemorsa 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.
Mr Grainger said: This evidence matches data we have from tagging white sharks that shows them spending a lot of time many metres below the surface.
The study examined the stomach contents of 40 juvenile white sharks (Carcharodon carcharias) caught in theNSW Shark Meshing Program. The scientists compared this with published data elsewhere in the world, mainly South Africa, to establish a nutritional framework for the species.
Understanding the nutritional goals of these cryptic predators and how these relate to migration patterns will give insights into what drives human-shark conflict and how we can best protect this species, saidDr Gabriel Machovsky-Capuska, an adjunct Senior Research Fellow at the Charles Perkins Centre and a co-author of the study.
Mr Grainger said: White sharks have a varied diet. As well as east Australian salmon, we found evidence of other bony fish including eels, whiting, mullet and wrasses. We found that rays were also an important dietary component, including small bottom-dwelling stingrays and electric rays.
Eagle rays are also hunted, although this can be difficult for the sharks given how fast the rays can swim.
The study found that based on abundance, the sharks diet relied mostly on:
The remainder was unidentified fish or less abundant prey. Mr Grainger said that marine mammals, other sharks and cephalopods (squid and cuttlefish) were eaten less frequently.
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 metres in length, Mr Grainger said.
Read more:
Great white shark diet surprises scientists - News - The University of Sydney
