The juvenile seal, which authorities said looked in good shape, if not a little underweight, was moved to Garden Island from a boat ramp at the popular recreation spot on August 26, only for it to return.
On September 5, the Department of Parks and Wildlife moved the sunbathing seal to Penguin Island.
Marine park co-ordinator Melissa Evans said the seal was likely to re-appear.
“The bet is it will return because people have been feeding it,” she said.
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READ NOWMs Evans said that while the subantarctic fur seal was cute, people should keep their distance and not feed the animal.
“They’re very charismatic but they are wild animals and can bite,” she said.
The Perth Boat School posted on social media that the seal had been named “Jo”.