We all fall to the temptation of eating the chocolate bar over the apple and sharks are no exception. Researchers at Southern Cross University’s National Marine Science Centre at Charlesworth Bay have discovered sharks seasonally snack on prey that isn’t nutritious but is certainly delicious.
For some people, the Jaws theme is enough to send shivers down their spine. But not Bec Lipscombe.
“I was lucky enough to be diving out at the Solitary Islands at the end of last year. A shiver of smooth hammerheads swam past us and I was squealing with delight underwater. That was a bucket list item that I got to tick off,” Bec says.
As a Doctor of Philosophy (PhD) candidate at Southern Cross University’s National Marine Science Centre, Bec is hoping to change public perspectives on sharks through a project funded by the NSW Government’s Shark Management Program.
“They’re a misunderstood animal,” Bec says. “Sharks play a really important role in the marine ecosystem. They keep everything in balance and keep the ocean healthy.”
Bec’s research is investigating the diet, habitat use and health of white sharks, which she hopes will influence future management and conservation strategies.
Much like how humans are drawn to a creamy soup and crusty bread in winter and light protein with a side salad in summer, it appears these top predators also change their eating habits as the temperature drops.
“They will switch from eating low trophic-level species like mullet and rays in winter to different prey such as tuna, tarwhine and snapper in spring and summer,” Bec says.
“Changes in prey changes their health as well. We’ve found certain prey might not be supporting their overall health. It’s like they’re snacking on fried chicken at certain times of the year then they move to salads at other times.
“We look at the essential fatty acids in their muscle and blood, very similar to what we look at in humans. Essential fatty acids are needed for their growth and development and when they’re eating less nutritious food their essential fatty acids plummet. Then during spring and summer they increased.”
For Bec, there is hope that more research into sharks will lead to greater protection for them, with global shark populations declining by 70 per cent over the past 50 years due to overfishing.
“Over 300 species now are listed as endangered, vulnerable or near threatened. That’s over half of the entire shark species that we’ve discovered so far that are in threat.”
