Imagine a massive underwater mountain made of volcanic rock, hidden beneath the waters of an inland sea. This is the essence of the Superior Shoal, a submerged peak that towers nearly 300 meters from the floor of Lake Superior. Discovered in 1929, the shoal lies within the world’s largest freshwater conservation area, approximately 70 kilometers from the nearest shoreline, making it a remote and enigmatic feature.
Recently, a team of researchers from Lakehead University in Thunder Bay, Ontario, along with a film crew, embarked on an expedition to explore the Superior Shoal in early September. Their mission was to gather crucial data on how this extensive underwater structure influences the ecosystem of Lake Superior.
Describing the shoal as a unique formation with significant implications for understanding Lake Superior’s ecosystem, Michael Rennie, an associate professor at Lakehead University and research fellow at the International Institute for Sustainable Development-Experimental Lakes area, highlighted its potential as a biodiversity hotspot akin to seamounts in the oceans.
Over a span of nine days, the expedition members, supported by a Canadian government grant, journeyed from Duluth, Minnesota, to the Superior Shoal aboard the research vessel Blue Heron. Living and working on the 83-foot trawler, the team conducted various experiments to study how physical processes such as currents, waves, and light penetration interact with the biological community around the shoal.
Rennie emphasized the importance of the Superior Shoal in sustaining the Lake Superior trout fishery, pointing out the presence of distinct strains of lake trout, including redfin, leans, and siscowet. These trout populations have notably rebounded without human intervention following the fishery decline in the 1960s and ’70s.
In addition to scientific research, filmmakers from Bruce County, Ontario, documented the entire expedition. Yvonne Drebert and Zach Melnick, known for their work with Inspired Planet Productions and the Royal Canadian Geographical Society, sought to capture rare footage of the Superior Shoal and its diverse fish species, particularly the redfin lake trout.
To explore the depths of the shoal with precision, the filmmakers utilized a sophisticated underwater robot, also known as a remotely operated vehicle (ROV). This high-tech ROV, designed in collaboration with Boxfish Robotics in New Zealand, boasts advanced features like an acrylic dome for deep-sea exploration and underwater optics correction. The footage obtained during the expedition will contribute to a new TV series titled “Hidden Below: the Freshwater World” and a science documentary highlighting the importance of protecting lakemounts, similar to seamounts in the oceans.