In an exceptionally close encounter in 2012, Mullaloo Surf Lifesaving Club member Martin Kane was rammed by a three-metre shark and knocked into the water. He escaped unharmed, but the incident sent a shockwave through the club and broader community. Three years on, the club, in collaboration with Curtin University researchers, are going hi-tech in an effort to prevent future attacks.
The joint collaboration, known as BeachLAB, is developing and testing acoustic technologies for shark detection. Having been awarded funding by the WA State Government, Curtin University has made significant advances in understanding how sonar can help protect beach-goers.
The group has deployed a system comprising a number of acoustic detection receivers, including two sponsored by RPS MetOcean, that cover around a kilometre of swimming beach area at Mullaloo’s main beach, in front of the Surf Life Saving Club.
Dr Miles Parsons, Curtin University’s Centre for Marine Science and Technology, explained the alert system works by recognising marine animals previously fitted with an acoustic tag travelling in the monitored area.
“When a shark or other tagged animal passes through the monitored area at Mullaloo Beach, a signal that is regularly emitted from their tag is then picked up by the strategically placed receivers in the water,” Dr Parsons said.
“Once the signal is picked up, the receivers then transmit a signal directly to the beach management system which sets off the audible alarm and flashing lights stationed on the beach, alerting swimmers to the potential danger and prompting them to take immediate action.”
BeachLAB will be testing the application and performance of a number of beach safety related technologies, using the array and its moorings as a real-world platform. Planned BeachLAB projects include the detection of rip currents along the beach and the detection of sharks using sonar systems.
The main focus of BeachLAB will be relaying detection of any potential hazard back to the central alarm system in real-time. Warning siren sounds during daylight hours when beachgoers generally swim. During night and off-peak hours, the system will only activate the red light warning.
The project will complement existing shark detection strategies at Mullaloo Beach including Department of Fisheries satellite-linked acoustic receivers that send an automated alert to SurfCom, as well as Twitter and SharkSmart, if a tagged shark is detected.
Mr Carlo Tenaglia, President of Mullaloo Surf Life Saving Club, believes that real-time, beach-based alarm systems are an effective way to alert swimmers.
“Other existing warning systems in place transmit information to an app or mobile phone, however, beachgoers generally wouldn’t have these devices with them in the water, or even necessarily take them onto the sand,” Mr Tenaglia said.
“A siren and red light are universal warning signs for danger and prompt swimmers to take immediate action to exit the water.”
Mr Tenaglia also explained that the Club hopes to extend the detection buoys along the Mullaloo coast in the future.
“The monitored area can be expanded by placing additional detection buoys at spaced intervals, forming a detection line for as long as required, creating a larger monitored area, and hopefully safer area, for local swimmers,” Mr Tenaglia said.