A bull shark under surveillance left scientists scratching their heads after it seemed to begin travelling down a major roadway in New South Wales.
Marine biologists noticed the predator – or at least its tag – was moving along the Princes Highway between Shellharbour and Wollongong, having apparently quit the sea at Shell Cove on Wednesday morning.
Department of Primary Industries scientist Amy Smoothey said the tag, which had been picked up by an environmentally conscious beachgoer, had been returned.
"He knew that it was valuable so he put it in his car amongst all the other rubbish that he picked up," she said.
"As a result of the GPS satellite tracking we have watched this tag travel from Barrack Heights to Wollongong University and back for the last few days."
'Still swimming'
The device had been tracking the 1.95-metre male as it made its way down the coast of Australia from Evans Head, near Ballina.
"It popped off as it should have done and the shark is still healthy, swimming around," Dr Smoothey said.
"What is exciting is we are able to get that tag and determine where that shark has been.
Dr Smoothey said there was not much time to retrieve a tag before the information was lost.
"When they pop off we only have a window of around a week for us to recover the tags before the satellite detection ability gets lower and lower," she said.
The pop-off tags are fitted below the dorsal fin of sharks and enable tracking for 120 days.
The tags are self-releasing and wash up on shorelines anywhere along the coast where they are retrieved by Fisheries officers.
