In late July, a boater on the West Coast of Canada noticed something strange. A huge, forested island was floating in British Columbia’s Williston Lake, one of the largest human-made reservoirs in the world. The mass — full of trees, birds and other animals — puzzled locals, who had never come across it before, and it was not on any map.

“It was a pretty amazing sight to see, never seen anything like that in my 40 years in this country,” said Rocky Avery, a friend of the boater and local resident. In August, he posted photos and a video of the island on social media to notify people of its presence ahead of an upcoming fishing derby. They soon went viral.

Bob Gammer, a spokesperson for B.C. Hydro, the government-owned power utility that runs the reservoir, initially thought the photos and video were a hoax created with generative AI.

“In the days of AI, you really needed another form of verification or evidence, like a corroborating eyewitness account,” he said. “And soon, we got that.”

A satellite image snapped on July 21 confirmed that the island was, in fact, real and in the reservoir. The picture shows a green mass about 150 yards (137 meters) long and 75 yards wide — nearly the size of two football fields — floating in the water.

The island then disappeared in mid-August. But just days ago, on Aug. 31, B.C. Hydro found it floating nearly 20 miles northwest of its original location.

So, what exactly is this vanishing island?

Gammer said that the island may have formed from logs and woody debris that accumulated over many years along the shoreline. As the materials gradually decomposed, plants and trees took root and created a habitat.

The mass of plant and animal life may have moved away from the shore because the reservoir is at its highest in 14 years, due to high winter snowpack and heavy summer rain, Gammer said. “Suddenly, there are all of the right conditions to potentially lift this kind of little island from where it was and bring it out into open water.”

However, not everyone is convinced by this explanation. Geologist John Joseph Clague of Canada’s Simon Fraser University said, “There is erosion occurring, and trees do collapse into the lake, but they don’t kind of form this very large mat of forested material.” For now, he remains perplexed by the mysterious mass.

Whatever its origins, it’s “a phenomenal sighting,” said Rebecca Helm, a marine ecologist at Georgetown University. Similar floating islands have been spotted elsewhere in recent years, including a well-known one called the Forty Acre Bog in Wisconsin’s Lake Chippewa. They used to be more common before widespread logging and damming, which blocks the flow of wood downstream.

“This island feels more like an old ghost than a shocking new occurrence, something humans used to see much more regularly,” Helm says.

While the island is generating a lot of buzz across Canada and beyond, Gammer warns people to keep their distance since the base is probably a “delicate, thin layer of logs.”

7月下旬，加拿大西海岸一名划船者发现了一件怪事：不列颠哥伦比亚省威利斯顿湖上漂浮着一座巨大的森林岛屿。威利斯顿湖是世界上最大的人工水库之一。这座岛上长满树木，栖息着鸟类和其他动物，令当地居民困惑不已——他们从未见过这样的景象，地图上也没有标注。

“那景象相当壮观，我在这个国家生活了40年，从没见过这样的东西，”划船者的朋友、当地居民洛基·艾弗里说。8月，他在社交媒体上发布了这座岛的照片和视频，以便在即将举行的钓鱼比赛前提醒人们注意。这些内容很快走红。

BC Hydro是运营该水库的政府所有电力公司。其发言人鲍勃·加默起初认为，这些照片和视频是用生成式人工智能制造的骗局。

“在AI时代，你确实需要另一种验证或证据，比如目击者的佐证，”他说，“很快，我们就得到了。”

7月21日拍摄的一张卫星图像证实，这座岛确实存在，且位于水库中。图像显示，一块绿色物体漂浮在水面上，长约150码，宽约75码，接近两个足球场大小。

这座岛随后在8月中旬消失。但就在几天前，8月31日，BC Hydro发现它漂浮在最初位置西北近20英里处。

那么，这座消失又重现的岛究竟是什么？

加默认为这座岛可能是多年来沿岸积累的木头和木质碎屑形成的。随着材料逐渐分解，植物和树木扎根生长，形成了栖息地。

由于冬季积雪量大、夏季降雨充沛，水库水位达到14年来最高，这团动植物可能因此脱离岸边。“突然间，所有条件都齐了，有可能把这种小岛从原处抬起，带到开阔水域。”

然而，并非所有人都认同这一解释。加拿大西蒙弗雷泽大学地质学家约翰·约瑟夫·克拉格说：“确实存在侵蚀，树木也会倒进湖里，但它们不会形成这么一大片森林物质。”目前，他仍对这座神秘物体感到困惑。

乔治城大学海洋生态学家丽贝卡·赫尔姆认为这是一次非凡的发现。近年来，其他地方也出现过类似的漂浮岛，包括威斯康星州奇佩瓦湖上一个著名的“四十英亩沼泽”。在大规模伐木和筑坝阻断木材下游流动之前，这类现象曾更为常见。

“这座岛更像一个古老的幽灵，而非令人震惊的新现象，它是人类过去更常看到的东西，”赫尔姆说。

加默警告人们对该岛保持距离。他指出，岛的底部很可能是“一层脆弱而稀薄的木头”。

(Translated by DeepSeek)