A DEVICE which uses boat hulls to pump out the sound of feasting killer whales is showing promise as a cost-effective shark-deterrent.
EGO-360 Speakers CEO Christopher Bignell, a regular at the Fremantle Markets for the last six years, has teamed up with sound recordist Ken Eichenberg of Wavehouse Studios to create Project Noah WA, which they say may deliver a device that deters sharks without any marine life being harmed.
“It makes the shark feel surrounded, and they need to leave,” explains Mr Bignell.
His small, portable lime green speaker looks like something you might take on a picnic and it’s hard to imagine it scaring a fully grown shark – until he turns it on.
“These speakers produce sound frequencies of a speaker 10 times the size and 10 times as powerful. They push sound waves into a surface and the surface amplifies from its basic resonance. So, stick this on any surface and it’ll become your speaker,” he shouts over the unbearable noise as he turns mate Carl Richards’ front room in South Fremantle into a pod of screaming killer whales.
Mr Bignell and Mr Eichenberg starting testing the Noah- SharkOmni when this year’s Margaret River Pro surf competition was cancelled after two shark attacks in Gracetown.
“We put five speakers in the hull of the dive boat and went out to Bunker Bay. We recorded the sound and found it was the same under water as it is above; really irritating, really disorientating,” says Mr Bignell.
“There were 20 sightings of sharks the week before in Bunker Bay. We didn’t see any.”
Previous models have failed because sharks have been able to trace the sound back to the speaker and aren’t fooled, but Mr Bignell says his model uses omni-directional sound.
“Sharks don’t have ears, they have little hairs from their mouth to their gills that pick up sensation. They sense lateral sound, which is straight direction, and omni, which is all directions,” says Mr Bignell.
The pair are now researching whether sharks will only respond to the sound of local killer whales.
They got the inspiration from the Gulf of Mexico, where killer whales started turning on sharks as fish numbers diminished. The sharks had been feeding on seals, but after the orca attack they disappeared from the area for two years.
“But we aren’t trying to scare them off completely,” he says.
“This is where we need more research. You might only need to give it a two-minute burst. And whatever is in the area has gotten well out of there. This is absolutely harmless for the sharks. All it’s going to make them do is leave their immediate area.”
Mr Bignell says repelling sharks will help WA’s tourism industry.
Mr Richards runs a charter boat and says he’ll be using the speakers.
“We don’t need to kill sharks, we don’t need to set up nets that are going to kill other marine animals, but setting something up to scare sharks away is perfect.”
Mr Bignell says they are gathering funds for further research through crowd funding campaign at Projectnoahwa, but the Noah- SharkOmni is already available for purchase, complete with sounds of four ochres surrounding and killing a great white shark off South Australia.
by MOLLY SCHMIDT