Update: A 2m shark moving along the coast has caused the closure of several beaches.
Trigg Beach was closed after a 2m shark was seen 100m offshore.
The shark moved down the coast causing Scarborough beach to be closed about 1.40pm, Trigg Beach has been reopened.
A Surf Life Saving WA spokesman said the shark was sighted from the Westpac Lifesaver Rescue helicopter this afternoon.
He said it was heading south and the species of shark had not yet been identified.Trigg Beach was closed two days ago when 13 Tiger sharks were spotted feeding from a dolphin carcass just 30m offshore.