The Great Lakes report card reveals a mixed bag of results, but what's missing might be more concerning than what's there. The 2025 assessment from the U.S. EPA and Canada highlights both successes and ongoing threats to the world's largest surface freshwater system. While drinking water quality and beaches are in good shape, invasive species and algae blooms remain significant challenges. Climate change, once a prominent concern, has been notably absent from the latest report, despite its clear impact on the lakes' physical characteristics.
The report scores each of the five Great Lakes on a scale of good, fair, or poor, based on nine key factors: drinking water, beaches, fish consumption, toxic chemicals, habitat and species, invasive species, nutrients and algae, groundwater, and watershed impacts. However, it's the absence of climate change from the assessment that raises eyebrows.
In the 2022 report, climate change was described as an emerging threat exacerbating other challenges. Yet, in the 2025 version, it's conspicuously absent, with only a mention of changes in physical characteristics like declining ice cover. This omission is particularly concerning given the long-term datasets showing the Great Lakes are experiencing significant changes, such as increased annual precipitation, warmer water temperatures, and reduced ice cover.
Despite these challenges, the report highlights some bright spots. Drinking water quality from the Great Lakes has remained good and stable for a decade, serving over 40 million people, with 97% meeting health standards in 2023. Beaches, enjoyed by millions and vital to local economies, have also been rated good and stable over the past decade, though some remain unsafe due to bacteria contamination.
However, the report paints a more ominous picture when it comes to invasive species. The impact of these species has more than doubled since 1950, with zebra and quagga mussels, considered the worst invaders, causing substantial ecological and economic harm. These mussels, native to eastern Europe, arrived in the U.S. via ballast water in the late 1980s, disrupting the food web and pushing fish populations to the brink. Their populations are increasing in deeper waters of Lake Michigan, while remaining low and localized in Lake Superior.
The emerald ash borer, another invasive species, continues to devastate forests around the region, killing ash trees by eating tissues under the bark. Since its detection in the U.S. in 2002, it has killed hundreds of millions of trees, with the Midwest bearing the brunt of the damage.
Nutrient loads and algae blooms, driven by agricultural fertilizers, are also degrading water quality across the Great Lakes. Blue-green algae blooms, caused by bacteria, can release toxins harmful to humans and wildlife. These blooms are particularly problematic in western Lake Erie and localized areas like Green Bay, Saginaw Bay, and Lake St. Clair.
Despite the report's findings, there's a disconnect between the data and the reality on the ground. Efforts to clean up legacy pollution and restore habitats have led to some improvements, but many communities still struggle with lead pipes and affordability challenges, making it difficult to rely on their drinking water supplies. This highlights the need for a more comprehensive approach to assessing the health of the Great Lakes region.
The report's omission of climate change and the ongoing challenges it presents underscore the complexity of managing the Great Lakes. As the lakes continue to evolve, the need for proactive and integrated solutions becomes increasingly clear. The question remains: How can we effectively address these issues and ensure the long-term health of this vital ecosystem?
