August 06, 2026
Whitefish Historically, lake whitefish (atikameg to local Indigenous peoples) have maintained a special status in the Great Lakes region as a source of sustenance and livelihood that remains important today. Whitefish have survived numerous challenges to the ecology of the Great Lakes, including the establishment of invasive species such as the sea lamprey, which wreaked havoc on fish populations throughout the Great Lakes beginning in the 1950s.
More recently, the quagga mussel has emerged as a threat. This small bivalve became established in the Great Lakes in the late 1980s. Despite its small size (an average adult measures roughly an inch) and an appearance far less frightening than the sea lamprey, the quagga mussel has nonetheless been linked to the widespread disruption of the Great Lakes food web.
The proliferation of quagga mussels has coincided with a significant decline in whitefish populations in the Great Lakes, particularly in large parts of lakes Michigan and Huron. The situation points to the delicate equilibrium necessary to sustain the Great Lakes and the fish that define the region
Whitefish are part of the “salmonid” group of fishes that includes trout and salmon. They are found throughout the Great Lakes, with lakes Michigan and Huron historically supporting the most abundant populations and the most productive fisheries. Prized for its mild flavor, the lake whitefish has long played an important role in supporting tribal culture, commercial fisheries, and the locally sourced food economy, including the many fish shops, markets, and restaurants that offer customers this familiar staple of the Great Lakes experience.
Unfortunately, too few young whitefish are surviving to the adult stage. The problem: Quagga mussels filter out algae from the water column that would otherwise feed zooplankton, the microscopic animals most juvenile fish feed on.
A diver checks equipment on Lake Michigan’s Good Harbor Reef at Sleeping Bear Dunes National Lakeshore, where millions of mussels were scraped off rocks in 2016 and monitoring continues. Photo courtesy of Invasive Mussel Collaborative. How can such a small mussel cause such a problem? Sheer numbers.
Unlike their smaller cousin, the zebra mussel, quagga mussels can occupy deeper areas and are less reliant on rocky habitat, meaning their habitat range encompasses nearly the entire lake bottom, with populations in the trillions.
Except in Lake Superior, which is less hospitable to quagga mussels and where whitefish populations have so far remained stable, quagga mussels are now the dominant feature of the benthic (bottom) zone of the Great Lakes. Their filtering has completely changed the flow and availability of energy in the system, resulting in uncharacteristically clearer water and fewer resources being available for fish.
Whitefish have proven particularly sensitive to this disruption. Prey fish populations that support other fish species have also declined in lakes Michigan and Huron, but the impacts to other game fish species have thus far been less significant. And while efforts to revitalize historic river runs of whitefish continue and more productive areas of lakes Huron and Michigan, such as Saginaw Bay and Green Bay, still produce young whitefish, that does not lessen the concern.
Consistent funding and research on the dynamics of maintaining the smallest pieces of the food chain are just as important as research on iconic species such as lake whitefish to inform adaptive management. Despite being established for many decades, quagga mussel populations remain dynamic. Continued monitoring of their populations and research into control options are critical.
There is still much to learn, and the clock is ticking. The vulnerability of lake whitefish – these unique freshwater marvels – is a cautionary tale: Without proper care and continuing to grow our understanding of these fish and how they depend on a complex ecosystem to survive, we are on a perilous path for valuable resources that define the heritage of the Great Lakes.
The small invasive quagga mussel presents big problems for lake whitefish. Credit: U.S. Geological Survey. Research into controlling invasive quagga and zebra mussels is critical to restoring and sustaining a healthy, balanced Great Lakes ecosystem that can support species such as lake whitefish. While controlling these mussels poses a more complex problem than sea lamprey, we can look there for a model.
A multinational intervention aimed at controlling sea lamprey in the Great Lakes commenced in the 1960s, helping numerous Great Lakes fish species that had collapsed after sea lamprey became established.
Similar partnerships such as the Invasive Mussel Collaborative – a consortium of federal, state, provincial, and tribal agencies and nongovernmental entities – seek to advance the science of mussel control.
The Great Lakes Spawning Whitefish and Invasive Mussel (SWIM) Project, a multi-agency working group, was formed in 2022 to prioritize the implementation and assessment of invasive mussel control technologies that show promise for improving spawning and nursery habitats for lake whitefish.
Adapted from an article by Stephen Lenart of the Michigan Department of Natural Resources in the 2025 Michigan State of the Great Lakes Report.
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