Hidden island on Williston Lake: phenomenon caused by plants growing on wood debris

The island is about 9,800 m2 wide on artificial lake Williston, covered with large trees and many animals living, constantly disappearing and reappearing.

According to Science Alert, the island attracted attention after appearing in photos and videos posted on social networks by local boatman Rocky Avery in mid-August.

Bob Gammer, a spokesman for BC Hydro, the power company that manages Williston Lake and the WAC Bennett dam, said many people initially doubted the island was real and thought the image was created by AI. "In the age of AI, you really need another form of verification or evidence, such as an independent eyewitness account," Gammer said.

To verify, experts compared free data from the European Space Agency's (ESA) Sentinel-2 Earth observation satellite. As a result, the 9,800 m2 island appeared as a small blue dot on Williston Lake, the largest freshwater lake in British Columbia province, on July 21.

According to Scientific American, the strange thing is that on August 5, the island seemed to "evaporate". In mid-August, satellite images showed it reappearing, about 32 km northwest of the location where it was first seen, then continuing to disappear. On August 31, Rocky Avery announced on social networks that he had "found" the island, this time in Ospika - the river that flows into Williston Lake.

BC Hydro believes the island was formed through years of vegetation growing on blocks of wood debris along sheltered sections of the lake's shoreline. This block separated from the shore because the lake water was at its highest level in 14 years, when the large amount of snow accumulated from winter melted and continuous rains fell in the summer. "Suddenly, all the right conditions appeared to separate the small island from where it was located and put it into open water," he said. "The fact that it seems to have disappeared does not mean it sank to the bottom of the lake, but may have returned to a more private area along the shore."

According to the Guardian, the island is teeming with life with birds and small animals living among the coniferous and broadleaf trees. Underwater root systems can also be a hiding place for some fish.

Experts have not determined how old the trees on the island are, but locals speculate they may have lived for decades. "It's not a small bush, it's an island with big trees. This is not an everyday thing. It's really strange," Gammer said. He likened these growing conditions to hydroponics, saying the plants "are well-nourished, grow on decomposing food with a lot of water, and can grow quite quickly."

Similar islands have appeared in several places around the world, such as Forty Acre Bog Island on Chippewa Lake in Wisconsin, USA. This giant floating island is said to have existed for decades, held together by peat, roots and plants.