Aerial beach patrols detect as few as one in eight sharks and give the public an inflated sense of protection, a NSW government report says.
The world-first study by the NSW Department of of Primary Industries was based on a trial at Jervis Bay on the NSW south coast, using artificial sharks placed at various depths, Fairfax reported on Saturday.
It found plane crews spotted just 12.5 per cent of the dummies and helicopters detected 17.1 per cent.
"This is a clear concern when the purpose of these patrols is to provide a warning of shark presence to the beach going public," the report said.
The findings call into question millions of dollars of government funding, sponsorship and donations poured into patrols across Australia.