Much of Lord Howe Island has been closed to non-essential visitors due to an outbreak of myrtle rust, a highly contagious plant fungus.

Lord Howe Permanent Conservation Park, which covers about 70% of the World Heritage-listed island, has been “temporarily closed to all non-essential visitors with immediate effect,” Lord Howe Island Council said.

Myrtle rust was discovered on the island on 3 February. According to the council, despite continued treatment and preventive fungicide spraying, weekly sweeps revealed three more infested sites, two of which were located about 230 meters from the boundary of the permanent park-reserve.

Atticus Fleming, chairman of the board of Lord Howe Island, told Guardian Australia that all four infected sites are located within settlements on the island.

“It was the fact that they were close to the edge [preserve] this was the reason for the closure [it],” He said.

Myrtle rust infects plants myrtle a family that includes eucalyptus trees, paper barks, and tea trees. The fungus infects flower buds and new shoots, affecting the ability of plants to photosynthesize.

There are concerns that myrtle rust may affect myrtle species endemic to the island, including mountain rose (Metrosideros nervulose), scaly bark (Syzygium fullagaria) and the Gnarled Moss Cloud Forest, an endangered forest that tops Mount Gower, the island’s highest mountain.

The fungus produces thousands of spores that remain viable for up to three months and are easily spread by wind, rain, and on clothing, skin, hair, shoes, and equipment.

“Due to the increasing risk, the closure of the permanent park-reserve is being carried out to prevent spread as a result of human activity,” the message says. “Rust can change the look of our mountains and forests, it can change food webs and ecology, and potentially affect world heritage values.”

About 50 local residents attended an information meeting held on Thursday evening in the island’s community hall with experts from the NSW Department of Planning and Environment and the Department of Primary Industries.

Fleming said the board would be reviewing whether to close the reserve on a weekly basis.

“Our goal is to destroy myrtle rust,” he said. “It will take us a few weeks before we know if it was possible.”

“We’re not going to take risks given the importance of conservation values ​​on the island, but also considering the importance of these conservation values ​​to the island’s economy.”

Professor Robert Park, director of the Australian Cereal Rust Program at the University of Sydney, said myrtle rust was first detected in Australia in 2010 on the central coast of New South Wales.

“Rust is one of the most feared of all plant pathogens – it is rapidly spread thousands of kilometers by wind and can cause huge losses in crop production,” Park said.

“Myrtle rust has quickly spread across the east coast of Australia and has led to the disappearance of at least three types of tropical forests. It was discovered on Lord Howe Island in 2016 and extirpated, but has now managed to spread there again. This second invasion clearly shows how incredibly difficult it is to fight rust diseases when they are introduced into a new region.”

Operators on the island are keen to emphasize that while the reserve is closed, other activities are still open to tourists.

“We remain open for business with the exception of some activities,” said Stephen Sea, treasurer of the Lord Howe Island Tourism Association. “There are many more places that visitors can visit … The territory of the settlement itself is quite pleasant for walking, and that’s all [11] the beaches are open and people can still swim.”

Sarah Shields, media manager for Capella Lodge, said: “Walking in the parks is a big part of the island’s activities, but this time of year… you’ll be spending a lot more time in the water.

“March is indeed the peak time for Lord Howe Island in terms of maritime activity.

“The priority for the island at the moment is to stop the widespread spread of myrtle rust … We support that [the island board] do [but] we would also like the board to find a way for businesses to coexist while the board is looking into this matter.

“It’s like Covid is visiting the island again – exactly three years ago we closed the island.”

The permanent park reserve, which also covers Ball’s Pyramid and the islands adjacent to Lord Howe, was established in 1982 to protect the region’s biodiversity. 241 species of native plants grow here, of which more than 100 are found only on the island.