Conservation group WWF-Australia wants public donations to buy a commercial gillnet licence in water north of Cairns and set up a huge, Tasmania-sized, net-free refuge for dugongs, sharks and turtles in north Queensland.

The 85,000-square-kilometre net-free refuge will stretch from Cooktown to the tip of Cape York and become the world’s second-largest dugong refuge if it wins the co-operation of the Queensland government, WWF-Australia says.

Queensland has 25 per cent of the world’s dugong environment; warm shallow coastal waters with seagrass meadows.

About 10,000 dugongs now live off Queensland's east coast. down from 72,000 in the 1960s.

The Ecological Society of America estimated there were 72,000 dugongs along Queenslands’ east coast in the 1960s, but WWF-Australia now estimate there are now about 10,000.