A prehistoric fish drastically threatened by alteration of its spawning grounds, habitat fragmentation, and confinement due to dam construction, the lake sturgeon needs more advocates for its protection. Though the Laurentian Great Lakes, St. Lawrence River and its tributaries have been home to lake sturgeon longer than humans have been alive, and sturgeon have weathered all the stresses of two million centuries of existence, humans have managed to decrease its numbers and restrict its habitat range through dams, habitat alterations, overfishing and other activities.
The spawning of lake sturgeon is largely influenced by water temperature, current, type of substrate and quantity of vegetation. Restocking efforts have vastly improved lake sturgeon numbers In the St. Lawrence River and Laurentian Great Lakes but issues about the quality of the bottoms of these aquatic systems have become an important factor in developing restoration and protection strategies fro spawning lake sturgeon.
Gravelly substrate is a preferred characteristic of sturgeon spawning grounds. One study examined three reported spawning locations in a channel between lakes Erie and Huron. It was found that the bottom substrate was either round cobble (one location) or coarse gravel (two locations) (Manny and Kennedy, 2002). The location of the sites were at varying depths, but the water velocity was similar to conditions in which sturgeon were known to spawn historically. It is speculated that increased eutrophication of the Great Lakes and St. Lawrence River has resulted in loss of gravel beds due to an increase in plant matter and other anthropogenic influences.
A better understanding of the location, quality and success of spawning sites in the Great Lakes and connecting waterways is vital to conservation of Lake Sturgeon. All species and subspecies of sturgeon are imperiled worldwide due to the impacts of human activity. Here in the United States, Atlantic Sturgeon, which spawn in the Hudson River, were declared an endangered species in 2012. If the Lake Sturgeon is to avoid the same fate, further research regarding its life history and spawning habitat is essential.
Lake sturgeon called the Great Lakes and St. Lawrence River home many millennia before humans existed. The more we know about their life history and requirements, the better they will be protected.