Emergency services were called to Humpy Island in The Keppels about 4.37pm today after members of the public reported that a man in his 40s was bitten.
He suffered significant injuries to his neck, which are considered to be life-threatening, a Queensland Ambulance spokesperson told 9News.com.au.
A helicopter was sent to the scene with a medical team on board.
Humpy Island is one of the most popular islands in the Keppels known for camping, diving and snorkelling.
