The World Wildlife Fund's buy-up of commercial fishing licences should not be viewed as trying to shut the industry down, says its Australian director.
The WWF has spent $100,000 on one commercial Queensland fishing licence and is starting another campaign to buy a second.
Its aim is to protect the future of hammerhead sharks on the Great Barrier Reef, where the species is believed to be in serious decline.
WWF Australia conservation director Gilly Llewellyn says studies indicate the hammerhead population has declined between 63 per cent and 80 per cent in 50 years on the reef.
"We are not against sustainable fishing, and we support the 60,000 jobs that depend on a healthy reef. A healthy reef needs sharks, dugong, turtles and dolphins," Ms Lewellyn said.