A 2.5 metre shark has been spotted close to shore off Secret Harbour.
The bronze whaler was sighted by the Surf Life Saving helicopter around 10.12am on Wednesday about 30 metres offshore.
It is tracking north.
Although bronze whalers are not known to be aggressive, beachgoers are advised to be extra cautious when in the water.
Secret Harbour beach is now closed due to the shark sighting.
SLS Westpac Heli report 2.0m unknown sp. shark sighted 10:18hrs 29/09, RO318 Secret Harbour BEN Sign, north of Mandurah 20m offshore , Tracking North.
— Surf Life Saving WA (@SLSWA) September 29, 2021