Man attacked by shark at Britomart Reef in Great Barrier Reef

A man continues to fight for life after being attacked by a shark at the Great Barrier Reef.

The 59-year-old was airlifted to Townsville University Hospital after being bitten at Britomart Reef about 12.20pm on Sunday.

He was out on the reef with a group of people who brought him back to shore.

Paramedics initially treated him on the boat ramp before taking him to hospital.

7NEWS understands the bite was to his upper thigh.

The reef is a popular spot for snorkelling and spearfishing.