Scientists are worried the Great Barrier Reef is on the verge of being hit by the most damaging crown of thorns starfish outbreak on record.
Sections of the reef between Cooktown and Cairns are already in the grip of an outbreak, the fourth recorded since the 1960s.
"At the moment the crown of thorns are still ramping up in numbers," said Col McKenzie, who heads the Association of Marine Park Tourism Operators (AMPTO).
"I would expect it would be 12 months before we'll see a full-on outbreak off Cairns."
Scientists say the growing plague, which comprises at least a million starfish over hundreds of kilometres, is steadily moving south with the ocean current. Read more