White sharks appear to roam surprisingly frequently on the seafloor.
The great white shark is a feared human eater that many animals also go for. But what exactly is on the white shark’s menu? In a new study, researchers decided to unravel which animals fall prey to the ‘king of the ocean’. And the findings appear to be far more surprising than thought.
Stomach contents of the white shark
The researchers decided to examine the stomach contents of 40 young white sharks living off the East Australian coast. They then compared the results with data collected from South Africa to paint as complete a picture of the white shark’s menu as possible. The findings are surprising. Because the researchers discovered that the great white shark mainly roams the seafloor. “In the stomachs of the sharks we found remains of a variety of fish species that usually live on the seabed or are buried in the sand,” said research leader Richard Grainger. “This indicates that the sharks spend much of their time on the seabed. The stereotypical image of a shark protruding from the water while hunting is probably unrealistic.”
White sharks appear to have an extremely versatile diet. The study shows that white sharks mainly feast on Australian salmon (32.2 percent). They also like a bite of stargazers (a famille of jet-catching fish from the order of perch), the tongue (a brown spotted flatfish), and flathead fish (17.4 percent). In addition, rays appear to be an important snack, such as stingrays (14.9 percent). Finally, they certainly don’t let some coral fish shoot, such as the beautiful blue Achoerodus (5 percent). But it doesn’t stop there. “We also found evidence that white sharks sometimes eat eels, whiting, harders, and lionfish,” Grainger says. “Eagle rays are sometimes hunted, although this is quite a challenge for sharks, given the speed at which the rays can swim.”
The sharks studied, therefore, appear to be far less likely to be good for marine mammals, such as seals, dolphins, and cephalopods such as squid. “Hunting for larger prey, including other sharks and marine mammals such as dolphins, only happens later in life when the sharks are about 2.2 meters long,” Grainger explains. In addition, the researchers found that larger sharks have a high-fat diet, probably because of their high energy needs in view of the exhaustive treks they undertake. For example, it appears that white sharks migrate seasonally from northern Queensland to Tasmania. “This is in line with previous research showing that predators balance their diet well to meet their nutritional needs,” said researcher David Raubenheimer.
The findings suggest that white sharks spend much of their time many meters below the surface of the water, close to the seabed. A surprising discovery. The study, therefore, provides an important contribution to our understanding of the feeding and feeding habits of white sharks. “Understanding their diet and how this relates to migration patterns will also provide insight into what drives collisions between humans and white sharks,” said researcher Gabriel Machovsky-Capuska. “Moreover, we can see from this how best to protect this species.” And that’s high on the agenda. Due to overfishing, hunting, and waste in the water, the shark is currently struggling. On top of that, there is also the current warming and acidification of the ocean. The results of the current study provide important information about white sharks that can help to sustain this fearsome but essential species.
Source and Reference:
” Great white shark diet surprises scientists ” – University of Sydney (via EurekAlert)
Image at the top of this article: Ryan Montgomery / Aerologistics Helicopters