Fisheries officials in the Great Lakes have reported a concerning resurgence of sea lampreys, an invasive species that poses a significant threat to the region's commercial fisheries. This unexpected increase is attributed to disruptions in lamprey control measures during the COVID-19 pandemic.
The sea lamprey, a North Atlantic native, infiltrated the Great Lakes through the Welland Canal in the late 19th century. With females capable of producing up to 100,000 eggs annually and lacking natural predators in the lakes, lamprey populations exploded, leading to a catastrophic decline in lake trout, which fell by 98% from the 1920s to the early 1960s.
In response, the Great Lakes Fishery Commission was established to combat this invasive species through targeted control measures. These efforts successfully reduced lamprey numbers by over 90% until the pandemic interrupted operations in 2020-2021, allowing lamprey populations to rebound.
As of 2024, lamprey numbers have exceeded target levels across all lakes, prompting officials to emphasize the need for continuous management to protect the fisheries from further decline.