Drones with infra-red technology and high-tech cameras could be used to spot sharks off WA beaches, which have been ranked as a global hotspot for fatal attacks, according to a Perth shark expert.
Surf Life Saving WA statistics show 101 sharks have been seen from the metropolitan helicopter this season, including nine great whites, 57 tiger sharks, two bronze whalers, 11 hammerheads and a whale shark.
But there could have been more than 500 sharks off the metropolitan coast, with a NSW Department of Primary Industries report finding helicopter surveys spotted only 17.1 per cent of sharks.
Wildlife Marine founder and director William Robbins, who wrote the report while working for the NSW Government, said people in helicopters struggled to spot sharks that were more than 2.5m below the surface or more than 250m from the aircraft.
Dr Robbins said it would be worth investigating whether aerial drones, such as those used by the military, could be equipped with infra-red sensors to look further into the water than human observers.
"White sharks in particular, they actually have a body temperature that's slightly higher than the surrounding water that they're swimming in," he said.
Surf Life Saving Australia is testing drones on Queensland beaches but they are being used to spot swimmers in distress.
Dr Robbins said drones could feed real-time video back to observers and it might be possible to scan the footage with a computer program designed to detect the shape of a shark.
He said he applied to the State Government for funding to investigate using drones for shark detection but was knocked back. A Department of Commerce spokeswoman said applications for funding were competitive and Dr Robbins was encouraged to apply in the future.
WA was yesterday named one of two global shark attack hotspots in the International Shark Attack File.
Australia recorded 14 shark attacks last year and two fatalities, comparable with the average 12 attacks and an average of 1.4 fatalities a year over the past decade.
But WA and Reunion Island were singled out as problem areas, with five and three fatalities respectively in the past two years.File curator George Burgess, from the Florida Museum of Natural History, said the reasons for the increase in attacks had not been identified.