Conservation group WWF Australia has bought a commercial shark fishing licence in an unusual move to protect the predators in the Great Barrier Reef Marine Park and beyond.

Conservation director Gilly Llewellyn said the licence cost $100,000, which includes a 1.2 kilometre net.

"We're going to take it out of the water and make sure it doesn't go fishing," she said.

"Hammerhead sharks are literally getting hammered out there.

"We have a chance to ... help save some of those sharks.

"This will also prevent dugongs, turtles and dolphins being killed as by-catch, and help the reef heal after the worst coral bleaching in its history."

The commercial shark catch on the Great Barrier Reef spiked from 222 tonnes in 2014 to 402 tonnes in 2015, Queensland Government figures showed.

Ms Llewellyn said that equated to 100,000 sharks last year.

The Federal Government has been considering whether to list some types of hammerheads as threatened species, which Ms Llewellyn said was needed urgently.

"This is a shot across the bow to the management authorities and to the Australian Government that we believe they should be protected," she said.

Purchase of old licence a 'PR stunt', fisherman says

The WWF's fishing licence has not been used since 2004, prompting questions about whether the move will make a difference.

However, Ms Llewellyn said it was a worthwhile purchase.

"Someone could buy it tomorrow and go fishing with it in a couple of months' time and it could be catching sharks again," she said.

Mario Fazio, who is a net fisher in the region, argued sharks were not under threat.

Especially considering the number of green and yellow protection zones across the reef, he said.

"It [the licence] is just a PR stunt and part of the political cycle," Mr Fazio said.

"It seems to be that fishermen are the flavour of the month."

WWF Australia is hoping donations will pay for the net fishing licence.