The lake trout (Salvelinus namaycush) was once a thriving, native species to Lake Erie. However, after numerous effects caused its decline and ultimate demise, it has been a difficult process of attempting to restore the species back to what it once was.
Lake Erie lake trout
Photo credit: The Buffalo News, courtesy of Bill Hilts Jr.
Lake trout was a prevalent species in the fish community of Lake Erie. This changed after commercial fishing moved into Lake Erie in the 1700s. The impacts of fishing only worsened in the 1800s when commercial fishing intensified. The intensification was caused by the increase in waters that were fished, including deeper waters. Additionally, gill nets came to be used as well as larger fishing vessels, all of which led to higher catch counts, therefore harming the lake trout population to a point of decline. The impact was so great, that the average annual harvest of lake trout in the late 1800s-1900 was more than 22,000 pounds.
Once managers started noticing what was happening in Lake Erie with the lake trout population, there was an attempt for management strategies to be implemented. One of these strategies was the regulation of the fisheries, which in the beginning was not very successful. Another strategy was to stock the lake with lake trout, which began back in 1879.
As time went on, even more negative factors were affecting the lake trout species. The first of these negative factors was the alteration of Lake Erie due to pollution and eutrophication. These negative effects altered the lake water, and therefore the lake trout’s habitat, which caused multiple issues, including declines in reproductive success. A second negative factor that began influencing the lake trout population was an invasive species, the sea lamprey (Petromyzon marinus), which was considered to be a parasite to the lake trout.
A sea lamprey attached to a lake trout
Photo Credit: International Joint Commission, credit: Marc Gaden, GLFC
It is believed that the complete depletion of the lake trout occurred sometime soon after 1965. Since then, various agencies have worked together to attempt the recovery process of the species in Lake Erie, including the New York Department of Environmental Conservation and the Pennsylvania Fish and Boat Commission. Management strategies to recover the species have included control on sport fishing mortalities, prohibition on the commercial fishing of lake trout in Lake Erie, and continued treatment for reducing the sea lamprey population.
Management strategies have shown some positive outcomes on the abundance of lake trout in Lake Erie thus far, as the annual survival of the lake trout has been increasing. As time goes on it is important that managers continue to keep up with maintenance stocking and that budgets remain in place for both stocking and the treatment of the sea lamprey. Things are looking up and it does look like the future for the lake trout in Lake Erie is bright.
Literature Cited
Floyd C. Cornelius, Kenneth M. Muth, Roger Kenyon, Lake Trout Rehabilitation in Lake Erie: A Case History,
Journal of Great Lakes Research, Volume 21, Supplement 1, 1995, Pages 65-82, ISSN 0380-1330,
https://doi.org/10.1016/S0380-1330(95)71084-X.