The Great Barrier Reef is benefiting from the allocation of protected zones that contribute to the growing number and quality of coral trout (Plectropomus leopardus) in the area.

A long-term study published in the Current Biology journal shows trout found in the protected zones, where fishing is prohibited, in the Great Barrier Reef are more abundant and are more adaptable when it comes to coping with cyclones compared to areas that allow fishing. The study also found that green zones had more reproductively mature coral trout, the primary target of commercial and recreational hook-line fishing.

Commissioned by the Australian Institute of Marine Science (AIMS) and the James Cook University ARC Centre of Excellence for Coral Reef Studies, the research compiles data gathered from underwater surveys done from 1983 to 2012 covering more than 40 percent of the Marine Park.

The results show coral trout biomass has more than doubled since the 1980s, with the most significant increases taking place after 2004, when the park was rezoned to increase the number of protected zones, also called green zones, from less than 5 percent to around one-third of the Great Barrier Reef.

"It's heartening to know the green zones are working as we had expected," says Michael Emslie, lead author of the study. "Among the world's coral reefs, fishing on the Great Barrier Reef is relatively light but it has still reduced the number and average size of the few fish species that are taken by fishers."

However, plenty of work still needs to be done for the Great Barrier Reef to gain a positive outlook. The combined effects of climate change, poor water quality from runoff, coastal development, and fishing have contributed to a shocking 50 percent loss of the reef's entire coral cover.

In fact, the World Heritage Committee of the United Nations Educational, Scientific, and Cultural Organization (UNESCO) is considering listing the Marine Park as an official World Heritage in Danger, which would alert the international community to focus conservation efforts in the area.

But the Australian government seems to be adamant in maintaining that the Great Barrier Reef is not in danger. If the Marine Park is listed as a World Heritage in Danger, the remaining coral reefs would be protected from Queensland coal mining that generates up to 787 million metric tons of coal, most of which are imported to China, every year.

"There is currently a campaign to list the Great Barrier Reef as in danger; we are doing all that we can to ensure the campaign does not succeed," Peter Varghese, secretary of the Department of Foreign Affairs and Trade, said.