On Sunday, much like other marine national parks in the country that close down during the monsoon, Koh Tachai — one of Thailand’s most idyllic and popular tourist spots — stopped receiving visitors. However, unlike other islands that would reopen to tourists in October, Koh Tachai will not.

Thailand’s Department of National Parks, Wildlife and Plant Conservation has now announced that the island, located in the Andaman Sea off the western coast of Phang Nga Province, will remain indefinitely closed “to solve the environmental and natural resources impact which is caused by tourism.”

“Thanks to its beauty, Koh Tachai has become a popular tourist site for both Thai and foreign tourists. This has resulted in overcrowding and the degradation of natural resources and the environment,” Tunya Netithammakul, director general of the department, told the Bangkok Post. “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.”

Koh Tachai is part of the famous Mu Koh Similan National Park. The island’s sandy beaches and pristine waters — home to rare blue corals, leopard sharks and manta rays — have attracted swarms of tourists, outstripping the island’s sustainable capacity and putting it at risk of irreversible ecological damage.

“In fact, Koh Tachai is preserved as a primitive zone, not a tourist site. 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,” Thon Thamrongnawasawat, a professor at Bangkok’s Kasetsart University, told the Bangkok Post. “This caused the island to quickly deteriorate. If it's not closed now, we'll lose Koh Tachai permanently.”

Tourism accounts for nearly 10 percent of Thailand’s gross domestic product. In the first quarter of 2016, the country received nearly 9 million tourists and, over the course of the entire year, 35 million tourists — drawn by Thailand’s beaches and islands — are expected to visit the country.

“The problem is that we have damaged our marine resources for a long time,” Thamrongnawasawat told the New York Times. “If we want it to recover, we must use strong medicine. I am not proposing to close all islands. But we have to start thinking about the plan to tackle the increasing number of tourists.”