LAKE SUPERIOR — The endless shores of Lake Superior stretch where dense forests of spruce, pine, and birch meet rugged cliffs and rolling hills — but beneath the waves lies a hidden world scientists and filmmakers are only now beginning to explore.
Dr. Michael Rennie, a freshwater scientist from Lakehead University, is leading the expedition. Speaking live from the research vessel Blue Herron, he explained, “A lot of what we are trying to understand on Superior Shoal is how physical processes, like currents, waves, and light penetration, interact with the biological community and how that might be involved in supporting that biological community that exists here.”
The expedition unfolded in real time through a livestream on the team’s YouTube channel, where viewers could watch, listen and ask questions as scientists and filmmakers shared discoveries from the depths.
Nicknamed the “Freshwater Everest,” Superior Shoal is a massive underwater lava formation that rises nearly 300 meters from the lakebed and spans 20 square miles. Sitting just 6.4 meters below the surface and about 70 kilometres from shore, it has long captured the imagination of researchers and adventurers alike.
The key question driving this mission: “Is the Superior Shoal a critical refuge for freshwater life?”
Currents, swirling back eddies, and algae growth on the shoal’s sunlit peaks may help explain why this isolated mountain is so rich in biodiversity compared to the open water around it.
Helping make this exploration possible are filmmakers Yvonne Drebert and Zach Melnick, both Fellows of the Royal Canadian Geographical Society. Drebert oversees the deployment of the team’s remotely operated vehicle, or ROV. “It’s about 60 pounds,” she explained during the livestream. “It can go about 500 meters deep and has eight thrusters.”
The exploration began in the shallows, said ROV pilot Melnick, where the team hoped to find rare varieties of lake trout. “Start in the shallows and hope to see some unique lake trout,” he explained. “These are the top predators in this lake, and there are rare types of lake trout like the redfin and the humper that have evolved to live on these underwater mountains.”
From there, the plan was to descend into deeper water. “We are planning to descend into the deep-water abyss around the edge of the mountain and hopefully we can see some deep-water species that are very rare to see on camera,” Melnick said. “Like the biggest lake trout of them all, the siscowette, and maybe even species like the Kaiai and the bloater, two very important Great Lakes species that, believe it or not, have never been filmed alive in nature.”
As the ROV scanned the underwater cliffs, the team marked the location of a lone log discovered pinned on the shoal 70 kilometres offshore. Whether carried there by storms, currents, or ice, it hints at the forces that have shaped this underwater landscape and could hold clues to the lake’s past.
Melnick noted that the shoal has long been a danger to shipping. “Because the mountain rises just a few meters below the surface, Superior Shoal has long been very dangerous for Great Lakes shipping,” he said, “so we will be keeping a close eye out for any signs of undiscovered shipwrecks.”
So far, Rennie added, “We haven’t seen any sign of shipwrecks yet. We’re also on the lookout for any other anthropogenic, or human, stuff that we see, because long ago this mountain would have popped above the surface as an island. So it’s conceivable that people could have made it out here at one point long ago, with large canoes and whatnot.”
Some archaeologists speculate that thousands of years ago, before the end of the Ice Age, when water levels were much lower, parts of Superior Shoal may have stood above water. It’s even possible that it supported human life—a mystery future research may one day explore.
For now, the team is gathering data on currents, algae, and fish populations while documenting a world few have ever seen. As Rennie put it, this is only the beginning of uncovering the mysteries of Lake Superior’s “Freshwater Everest.”