Wildlife authorities are trying to free a humpback whale tangled in rope off Rottnest Island.
It was first reported yesterday morning near Parker Point near Rottnest Island by a marine ranger conducting routine patrols.
A Parks and Wildlife spokeswoman said the animal did not appear to be in distress.
"It appears quite healthy — we first spotted it yesterday morning at around 11:15am," she said.
"The ranger was out doing routine sea lion monitoring when the whale was spotted and by [that] afternoon it had a satellite tag on it."
She said authorities were hoping satellite data would track the humpback whale's location and help determine how best to free it.
The Fremantle Sea Rescue volunteer group advised vessels to stay clear of the area to avoid causing distress to the animal.
Authorities are closely monitoring the whale and say it is currently not at risk of stranding.