State of the Great Lakes 2025
The State of the Great Lakes reports are developed by the governments of Canada and the United States, in collaboration with many partners, in accordance with the 2012 Canada-United States Great Lakes Water Quality Agreement. State of the Great Lakes assessments support the identification of current and emerging challenges to Great Lakes water quality and ecosystem health, and help inform and engage others.
What are the Great Lakes indicators telling us?
Overall, the Great Lakes are assessed by the State of the Great Lakes indicators as Fair and the trend is Unchanging. There has been tremendous progress to restore and protect the Great Lakes, including the reduction of toxic chemicals, and a reduction in the establishment of new non-native aquatic species. Some indicators demonstrate that there are still significant challenges, including the impacts of nutrients, especially in Lake Erie and localized areas of the other Great Lakes, and the impacts of invasive species. The coordinated actions of many agencies, organizations, groups and individuals are accelerating efforts to protect and restore the Great Lakes so they can continue to be a reliable source for drinking water, fishing, recreation and other uses that support the region’s economy.
Can we drink the water?
Yes, once treated. The Great Lakes remain a source for producing high-quality drinking water.
See the Drinking Water assessment
Can we swim at the beaches?
Yes. However, some beaches are occasionally unsafe for swimming due to bacterial contamination, indicating pathogen risks.
See the Beach assessment
Can we eat the fish?
Generally, yes. Great Lakes fish can be safely eaten by following consumption advisories. However,
unrestricted consumption of many fish is not yet possible, which has a greater impact on communities
that heavily rely on fish for food, and cultural, spiritual, or economic purposes.
See the Fish Consumption assessment
Have levels of toxic chemicals declined in the environment?
Generally, yes. Many chemicals, such as PCBs and mercury, have declined significantly in the Great Lakes
over the long term, however rates of decline have slowed in more recent years. Concentrations of some
toxic chemicals still pose threats to human health and the environment.
See the Toxic Chemicals assessment
Are the lakes supporting healthy wetlands and populations of native species?
Yes and no. Healthy coastal wetlands exist in each Great Lake basin. However, Great Lakes coastal
wetlands vary in quality, with the healthiest areas generally occurring in northern locations where the
footprint of human activity is lowest. Changes have taken place in the food webs of the Great Lakes to
varying degrees, and the impacts of stressors such as invasive Dreissenid Mussels continue. Populations
of native fish species such as Lake Trout and Lake Sturgeon have increased in response to restoration
efforts in several areas across the Great Lakes.
See the Habitat and Species assessment
Are nutrients in the lakes at acceptable levels?
No. High nutrient concentrations in parts of Lake Erie and in some embayments in other parts of the Great
Lakes still contribute to blooms of toxic cyanobacteria and nuisance algae. Very low nutrient levels in the
offshore waters of lakes Michigan, Huron, and Ontario have resulted in algal and organism production rates
below desired levels. Only Lake Superior has relatively good nutrient conditions, which helps to maintain a
healthy food web.
See the Nutrients and Algae assessment
Are we limiting new introductions and the impacts of non-native and invasive species?
Yes and no. The rate of introduction of new non-native species to the Great Lakes basin has greatly declined.
However, the impacts of established invasive species persist, and invasive species continue to spread within
and between the Great Lakes.
See the Invasive Species assessment
Is groundwater negatively affecting the water quality of the lakes?
Generally, no. Groundwater typically provides good quality water to tributaries in the Great Lakes basin and
to the Great Lakes. However, in some watersheds in the Great Lakes basin, groundwater contains elevated
levels of pollutants, such as nitrate and chloride. There are also groundwater sites contaminated by other
chemicals that are being actively investigated and remediated.
See the Groundwater assessment
Are land use changes or other stressors impacting the lakes?
Yes. Watershed stressors such as population growth, land-use activities, habitat loss and degradation, and other factors contribute to impairments of Great Lakes water quality and ecosystem health.
See the Watershed Impacts and Changes in Physical Conditions in the Great Lakes assessment
What is the status of each lake?
Lake Superior’s forested watershed and coastal wetlands help maintain water quality and a healthy aquatic ecosystem – Lake Superior is assessed as Good and Unchanging.
See the Lake Superior assessment
Lake Michigan’s habitats support a diverse array of plant and animal species and its waters provide opportunities for swimming and recreational use. However, invasive species and other stressors affect water quality and the lake’s food web – Lake Michigan is assessed as Fair and Unchanging.
See the Lake Michigan assessment
Lake Huron provides opportunities for swimming and recreational
use. It remains healthy despite algal blooms in some nearshore areas –
Lake Huron is assessed as Fair to Good and Unchanging.
See the Lake Huron assessment
Lake Erie’s successful Walleye hatches from previous years continue to
support excellent recreational and commercial fisheries. However, elevated
nutrient concentrations and algal blooms are persistent problems – Lake Erie
is assessed as Poor and No Trend.
See the Lake Erie assessment
Lake Ontario shows improvements in Lake Trout and Lake Sturgeon populations, but nuisance algae like Cladophora is distributed across broad regions of the lake’s nearshore zones – Lake Ontario is assessed as Fair and Unchanging.
See the Lake Ontario assessment
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The information contained within the State of the Great Lakes (SOGL) 2025 Report is a summary of science-based information from 42 sub-indicator reports.