Australian researchers are working on high-tech buoys that could alert lifeguards via satellite when a shark is lurking offshore.
The idea is to create networks of buoys a few hundred metres from beaches, creating an unbroken detection perimeter, says Hamish Jolly, co-founder of Perth company Shark Mitigation Systems.
The company has unveiled work on a prototype of the so-called "clever buoy", saying a polished version could be market-ready in as little as one year.
"We think it's going to be good for sharks and good for humans," Jolly says.
The prototype buoys are 25kg floating domes housing microprocessors and satellite transmitters.
They are connected by cable to a sonar transducer, which sits on the seabed and sends shark-detecting soundwaves to a radius of between 25 and 60 metres.
The sonar transducers are currently trained to detect moving objects at least two metres in length.
But Jolly says the plan is to fine-tune them to detect sharks based on the way the creatures move through the water.
"All sea animals have unique signatures based on the way they swim. It's their fingerprint," he says.
"The journey from here is to use these signatures, almost like face-recognition, to teach the software to hunt for the specific swimming characteristics of sharks."
Tests at Sydney Aquarium and the Abrolhos Islands off Western Australia have shown that the technology can distinguish between stingrays and sharks based on their sonar signature.
Jolly says the buoys could eventually detect the species of a shark based on the way it swims. With testing, the sonar range should also increase, he says.
The system would beat current methods of detection, such as electronic tagging, which picks up only about five per cent of sharks that end up near beaches, he adds.
The project is funded by Optus and relays warnings via Optus Inmarsat satellites.
At the moment, the plan is for a shark detection to trigger a warning light onshore, but Jolly says there is no reason warnings couldn't one day be sent directly to smartphones.
Shark Mitigation Systems has previously worked on high-tech swim suits that use special materials to camouflage swimmers in the water.
