A 3.5 metre tiger shark has been sighted off Perth's Trigg Beach.
The rescue helicopter spotted the shark about 300 metres off shore just before 8:00 am.
It was swimming in a south westerly direction.
Trigg beach has been closed.
Tags: perth, recreation, beach, shore, metre, 300 metres, rescue helicopter, orders of magnitude, bull shark, oceanic whitetip shark, great white shark, shark sighting, requiem shark, trigg beach, metre tiger shark, south westerly direction