A leading conservation group has purchased a shark fishing license worth AU$100,000 to keep it out of the hands of actual fishers.  The World Wildlife Fund (WWF) Australia hopes this will be the shot across the bow that gets the Federal Government to list the Hammerhead Shark as "endangered".

The cost of the license included a 1.2 kilometer net.

"We're going to take it out of the water and make sure it doesn't go fishing," Gilly Llewellyn of the WWF told the ABC.  "Hammerhead sharks are literally getting hammered out there," she added, noting that buying the license and leaving it on the desk will "prevent dugongs, turtles and dolphins being killed as by-catch, and help the reef heal after the worst coral bleaching in its history."

The license hasn't been used since 2004.  But prior to that, it was used to take 10,000 sharks a year for a decade.  More recently, the Queensland government reports that shark catches on the Great Barrier Reef almost doubled between 2014 and 2015: from 222 tons to 402 tons - about 100,000 sharks that year. 

"Hammerhead numbers have crashed in Queensland, possibly by 80 percent," said Llewellyn.  And that threw the food chain out of balance.

"After bleaching, algae spreads," Ms. Llewellyn said.  "Researchers found that where sharks were removed by overfishing, smaller predators like snapper became more abundant.  These snapper kill the algae-eating fish and the algae then overwhelms young coral."