Great white sharks prefer rock music
SMALL WAVES MAKE fin-like peaks near South Australia’s rocky Neptune Islands, a popular hangout for great white sharks. Standing on the deck of his boat Shark Warrior, Matt Waller – fourth-generation fisherman turned tour operator – is trying to lure the apex predators towards us using bobbing waterproof speakers. Flicking through songs on his iPod, he stops on an old faithful by grizzled Aussie rock legends AC/DC.
Since the 1960s, the waters of the Neptune Islands Group (Ron and Valerie Taylor) Marine Park, 60km south-east of Port Lincoln in SA, have hosted the Australian shark-diving industry – and for 13 years have been the only place in the country where you can cage-dive with sharks. Despite fears about the increasing frequency of shark attacks, and controversies around responses to them, great whites are listed as vulnerable and receive some degree of protection. Tour operators and researchers working out of Port Lincoln believe that the more safe and controlled encounters people have with the fearsome fish, the more likely they are to join the call for even greater levels of protection.
Historically, sharks have been lured towards tour boats by a trail of chum (or berley), a smelly mix of tuna oil and minced fish, which they can detect from several kilometres away. However, in recent times, recorded music has been found to exercise a similar attraction. “The first success we had,” Matt says, as he helps tourists into a cage at the back of the boat, “was with Back in Black and You Shook Me All Night Long”. There was also a 4.5m female that would arrive every time the marimba-heavy Sax and Violins by Talking Heads was played. In truth, sharks have eclectic tastes, and are attracted by many types of music,” adds Matt, who runs Adventure Bay Charters. But he has noticed they are more likely to respond to the lower frequency beats of hard rock.
Ringing the dinner bell
According to Dr Peter Klimley, a shark-tracking specialist at the University of California, that’s not as ridiculous as it seems; he’s used lab-produced sounds to locate sharks for tagging and tracking. Sharks ‘hear’ sounds from objects much further away than those they can see, using follicles in their skin as well as their ears to detect vibrations. As far back as the 1960s, American scientists were discovering that various species were attracted to irregular, pulsed sounds of frequencies at less than 375Hz.
Their so-called yummy sound theory suggests that this mimics the sounds of struggling, injured fish, and acts like a dinner bell. It’s a technique that Adventure Bay Charters have had to adopt since a 2011 CSIRO study recommended a reduction in chumming. Scientists had reported that a boom in cage-diving at the Neptune Islands had seen the population grow and sharks hang around for longer, signalling a change in their natural behaviour. Matt’s business, one of the youngest, lost out on a chumming licence soon after. Having heard that operators were successfully using music off the Mexican island of Guadalupe, he gave it a go, and now takes out 2500 passengers annually, using tunes as bait to draw in the sharks. Music also seems less disruptive to the sharks, Matt says. “They’re more curious and a lot less aggressive.”
While I’m out with Matt, death metal act Darkest Hour is the musical drawcard. A 5m great white rises from below and heads straight to the speaker, nuzzling it before sinking again, sending shivers of excitement through everyone in the cage.
This article originally appeared in the Nov-Dec 2015 issue of Australian Geographic.