Most of Lord Howe Island has been shut down due to the threat posed by an airborne fungus.

About 70 per cent of the island has been closed as authorities scramble to save the ecosystem, which includes 105 species of plant found nowhere else in the world.

The fungus — myrtle rust — is an exotic fungus which has been on mainland Australia since 2010, and was detected for the first time on Lord Howe Island on February 3.

Press PLAY below to hear the devastating impact the fungus could have

Chief executive of the Invasive Species Council, Andrew Cox, says testing shows rare plants found only on Lord Howe Island are “highly susceptible”.

“Because of the special plants and animals only found on Lord Howe Island, if we lose a species from there, that’s it. It’s the only place in the world they’re on, so it’s really important we get on top of this.”