UPDATE 5.40pm: Scarborough and Brighton beaches have been reopened after they were closed for the third time today due to a tagged great white shark being detected in the area.
The shark was detected at 3.54pm resulting in the beaches being closed. The shark has since been detected at 4.09pm, 4.14pm and 4.17pm.
The beaches were also closed at 12.30pm after detections from a receiver at Scarborough at 12.28pm, 12.30pm, 12.33pm and 12.40pm.
The beaches were reopened about an hour later after the shark was undetected following the closure and a helicopter fly-over also failed to spot the shark.
Scarborough Beach was first closed this morning after the shark was spotted there at 6.30am. The shark was tracked south towards Floreat and City Beach.
Floreat and City beaches were closed today after a tagged great white detection.
The tagged shark was first detected about 8am off Floreat but the beach was reopened about 10am.
Surf Life Saving WA detected the shark back in the area about 10.30am and closed the beach again.
City Beach was opened again just after midday but Floreat remains closed.
A 2.5m shark has also been spotted about 50m from shore at North Beach this morning.
The Department of Fisheries advise that the shark was tracked heading north from North Beach jetty about 11.10am.
A large fin has also been spotted off Rockingham Beach.
The animal was tracked heading south just before midday.
Meanwhile, further down south in Esperance, a 5m great white shark has been sighted about 600m off Bandy Creek Harbour.
The shark was moving north-west at 11.30am.