Highly Invasive Vampire Fish Returns to the Great Lakes, Disrupting Population Control Efforts Post-Pandemic

After the pandemic disrupted population control measures, the sea lamprey, an eerie parasitic fish nicknamed the "vampire fish" for its blood-sucking behavior, is making a resurgence in the Great Lakes. This species possesses a circular row of teeth, a serrated tongue, and an eel-like appearance.

Vampire Fish Population Pre-Pandemic

Sea lampreys, originally found in the northern and western Atlantic Ocean, invaded the Great Lakes in the early 19th century through the Welland Canal, connecting Lake Ontario and Lake Erie.

National Oceanic and Atmospheric Administration wrote that within a decade of its arrival, it gained access to all five Great Lakes, posing a significant threat by preying on commercially valuable fish species like trout, whitefish, perch, and sturgeon. The unchecked proliferation of lampreys over the next century led to the collapse of the trout fishery in the region.

As per Wired, sea lampreys had devastatingly reduced the annual commercial catch of lake trout in the upper Great Lakes from around 15 million to merely half a million pounds in the 1960s.

To counter their impact, expensive lamprey control efforts, costing $15 to $20 million annually, have been essential to enable lake trout recovery and prevent a potential crash of other sport fish populations.

While sea lampreys are considered a traditional delicacy in Europe and commercially fished in countries like Spain, Portugal, and France, they have not been widely appreciated as food in North America. The catastrophic effects of their invasion of the Great Lakes have necessitated a reevaluation of their significance in the region.

The Great Lakes Fishery Commission, in collaboration with the US Fish and Wildlife Service and Fisheries and Oceans Canada, has been effectively managing the highly invasive species population, boasting a 90% reduction in most areas of the Great Lakes, as stated on their website.

However, with the COVID-19 pandemic and travel restrictions, the progress faced an obstacle between 2020 and 2021 as it disrupted the agencies' ability to carry out crucial population management operations.

Vampire Fish Re-Emerge in Great Lakes Post Pandemic

According to The Wall Street Journal, fishery managers have observed an increase in the population of the parasitic sea lamprey across the Great Lakes.

While the exact extent of the increase remains unclear, a report from Undark Magazine in 2022 indicated that in 2020, crews responsible for population control could only treat around 25% of the target streams, but this improved to 75% the following year.

The treatment process involves the careful and timely application of pesticides called lampricides, which can be costly and labor-intensive, aimed at reducing the lamprey population.

The Great Lakes Fishery Commission was established in 1955 by the U.S. and Canada to control the sea lamprey population in the Great Lakes.

In an activity book for kids, the commission wrote that they are collaborating with various partners, including the United States Fish and Wildlife Service, Fisheries and Oceans Canada, and the United States Army Corps of Engineers, to apply lampricides and construct barriers and traps to reduce sea lamprey numbers by 90% in most areas of the Great Lakes.

Ongoing research by institutions like the United States Geological Survey focuses on developing new control techniques through the study of sea lampreys' scents (pheromones), trapping young parasitic sea lampreys, and monitoring their movements throughout the region.

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