During peak season, tour companies sell diving packages to tourists who come to the island and support a fledgling pop-up economy there. According to a Bangkok Post article, a university dean who spoke Sunday at a tourism fair organised by the government said 14 companies were still selling packages to Koh Tachai.

“A beach on the island can hold up to 70 people. But sometimes the number of tourists was well over 1,000 on the beach, which was already crowded with food stalls and tour boats. This caused the island to quickly deteriorate,” said Thon Thamrongnawasawat, the deputy dean of the fisheries faculty at Kasetsart University in Bangkok.

Koh Tachai is part of a national park that is closed off annually to tourists from May to October 15 for the duration of the monsoon season. But now it will be closed indefinitely.

Tunya Netithammakul, director general of the Department of National Parks, told the Bangkok Post newspaper that “thanks to its beauty” Koh Tachai had become a popular site for both Thai and foreign tourists, resulting in “overcrowding and the degradation of natural resources and the environment.”

“We have to close it to allow the rehabilitation of the environment, both on the island and in the sea, without being disturbed by tourism activities before the damage is beyond repair,” he was quoted as saying by the newspaper.

“In fact, Koh Tachai is preserved as a primitive zone, not a tourist site,” said Thon, referring to a designation that Thailand gives certain particularly vulnerable areas. “If it’s not closed now, we’ll lose Koh Tachai permanently.”

Additional reporting by Associated Press