Man attacked by shark near popular holiday island

A man was attacked by a shark on a popular holiday island.

The incident happened on Rottnest Island, near Perth, at around 10am on Saturday, a spokesman for the St John WA ambulance service told AAP.

The man in his 30s is in critical condition.

A rescue helicopter arrived at the island, 12 miles off the coast of Fremantle, to take the man to hospital on the mainland.

The man was transported by boat to shore at Geordie Bay on the north side of the island.

According to Surf Life Saving WA, a five-metre white shark was spotted 80 meters offshore at the time of the attack.

The Department for Primary Industries and Regional Development has urged people to be extra careful in the Geordie Bay area.

Rottnest Island, 11 km long and 4.5 km wide, is a popular tourist destination.