Shark attack closes Pyramids Beach

Surf Life Saving WA says the victim was treated by lifesavers and was stable when transferred to paramedics.

It's understood he was not seriously injured and SLSWA said he "left on his own accord".

The attack is believed to have occurred near Port Bouvard Bridge, which takes Old Coast Road across the Dawesville Channel in Mandurah, this morning.

SLSWA says the beach, also known as Pyramids Beach, is likely to remain closed for 24 hours.

Shortly before the attack SLSWA tweeted that a shark had been sighted in the water at Port Bouvard Bridge, south of Mandurah.

More details as they come to hand.