K’gari’s iconic lakes have existed for tens of thousands of years—but they haven’t always been full. New research shows that about 7,500 years ago, during a time of high rainfall, several of the island’s deepest lakes mysteriously vanished. Scientists believe changing wind patterns may have redirected rain away from the island. As the climate shifts again, the lakes’ long-term survival is no longer guaranteed.

Researchers believe shifting wind systems may help explain the mystery. Dr. Harald Hofmann, a co-author from the Commonwealth Scientific and Industrial Research Organisation (CSIRO), says regional wind patterns likely influenced where rainfall ultimately ended up.

“Prior research shows Minjerribah also experienced heavy rainfall events at this time, but, because of south-east trade winds that were occurring at the time, rainfall from the south only fed into lakes on Minjerribah, not those on K’gari,” he says.