Shark sighting validation call
SURF Life Saving WA says shark sightings should be verified so swimmers’ anger is not directed at lifesavers enforcing beach closures.
“If I look at the Clever Buoy example at City Beach, where that trial was conducted, and the number of beach closures, there was a significant amount of angst from the people, and that anger was directed at the lifesavers who were simply delivering the protocols and closing the beach,” SLSWA general manager Chris Peck told a Senate inquiry hearing into mitigating attacks in Perth last month.
Cottesloe resident Bryn Martin is the only attack victim at a patrolled beach after he was killed by a great white off Cottesloe Beach in 2011.
SLSWA issued 258 imminent threat warnings, causing at least 4600 people to leave the water on 40 patrolled beaches in the past two years.
At the hearing, Mr Peck said while people were altering how they used beaches, frequent closures made people “frustrated” and “angry”.
“The protocol (closes the beach) for an hour from the last sighting. So if we get to minute 59 and we see it again, the clock starts again,” Mr Peck said.
He said there was a need for sightings to be confirmed but despite attempts by helicopter or drone, SLSWA was unable to validate any shark being in the area when a beach was shut.
During Clever Buoy’s trial all hours for three months, 15 of the 27 shark detections were in SLSWA operating hours. The detections caused 15 beach closures, while there were seven closures for other reasons.
Clever Buoy general managing director Craig Anderson said while the trial did not include visual verifications, the former state government previously did “intensive independent due diligence of the accuracy and validation of the detection system”.
“During the trial it was tried to have the helicopter on-site as soon as possible after a detection, but this is not always achievable,” he said.
He said drones were being tested for verification but they suffered from limited visibility, wind and laws about flying at public places.
The “ultimate” shark confirmation would be Clever Buoy detecting a tagged shark, and a human sighting.
“This is why we have used sonar as the basis of the technology for detecting moving objects in the water and created a machine learning system to automate this and provide real-time information to beach authorities,” Mr Anderson said.