Assessing the Great Lakes

Why are the Great Lakes important?

The Great Lakes contain one fifth of the world’s fresh surface water supply and are the largest freshwater ecosystem on Earth, supporting rare and globally unique species and ecosystems. They provide a source of drinking water to approximately 28 million Canadians and Americans and are important to the economies of both Canada and the United States, supporting manufacturing, transportation, farming, tourism, recreation, energy production and other forms of economic growth. To the Indigenous communities around the basin, the Great Lakes waters, plants and wildlife provide a continuation of lifeways and a sense of identity. Indigenous communities recognize that the inherent value of the Great Lakes must be maintained through a relationship founded on respect and care.

How are governments working together to protect the Great Lakes?

The Great Lakes Water Quality Agreement signed by the Governments of Canada and the United States commits both countries to work cooperatively to restore and protect the water quality and ecosystem health of the Great Lakes. Through the Agreement, the Governments of Canada and the United States work with Tribes, First Nations, Métis, provincial, state and municipal governments, watershed management agencies, other local public agencies, industry and the public to ensure that the waters of the Great Lakes, through sound management, use and enjoyment, will benefit present and future generations of Canadians and Americans. In fact, 2022 marks the 50th anniversary of the signing of the Agreement – 50 years over which the two countries and their many Agreement partners have worked together to protect this valuable resource.

How is the health of the Great Lakes assessed?

The Governments of Canada and the United States, together with their many Agreement partners, have established a set of nine overarching indicators of ecosystem health directly linked to the Objectives of the Great Lakes Water Quality Agreement and supported by 40 science-based sub-indicators. For this report, more than 110 government and non-government Great Lakes scientists and other experts analyzed available data (for most sub-indicators this includes data up to 2019 or 2020) and reached consensus on the assessments of each indicator in relation to both current status and trend over time. Statuses are described in terms of Good, Fair or Poor conditions. Trends are described as being Improving, Unchanging, or Deteriorating and are generally assessed over a 10-year period. Refer to the State of the Great Lakes 2022 Technical Report for all sub-indicator reports.

How is the assessment of the Great Lakes used?

Great Lakes indicator assessments help governments identify current and emerging challenges to Great Lakes water quality and ecosystem health. Indicator assessments also help governments evaluate the effectiveness of environmental programs and policies in place to address challenges and identify priorities. In addition, indicator assessments help inform and engage other stakeholders, including the public, and provide information that in turn supports efforts to restore and protect the Great Lakes.

2022 Assessment of the nine Great Lakes indicators of ecosystem health

Great Lakes Indicator

2022 Assessments: Status and Trends

Drinking Water

Status: Good Trend: Unchanging


Status: Good Trend: Unchanging to Improving

Fish Consumption

Status: Fair Trend: Improving

Toxic Chemicals

Status: Fair Trend: Unchanging to Improving

Habitat and Species

Status: Fair Trend: Unchanging

Nutrients and Algae

Status: Fair Trend: Unchanging

Invasive Species


Status: Good Trend: Unchanging


Status: Poor Trend: Unchanging


Status: Good Trend: Undetermined

Watershed Impacts and Climate Trends

(Watershed Impacts)

Status: Fair Trend: Unchanging

(Climate Trends)

No Overall Assessment



Green status
Good: Most or all ecosystem components are in acceptable condition.
Yellow status
Fair: Some ecosystem components are in acceptable condition.
Red status
Poor: Very few or no ecosystem components are in acceptable condition.
Grey status
Undetermined: Data are not available or are insufficient to assess condition of the ecosystem components.


Improving: Metrics show a change toward more acceptable conditions.
Unchanging: Metrics generally show no overall change in condition.
Deteriorating: Metrics show a change away from acceptable condition.
Undetermined: Metrics do not indicate a clear overall trend, or data are not available to report on a trend.

Participating Organizations

Many people have been involved with the development of the State of the Great Lakes 2022 Report. Thank you to the authors and advisory committee members, as represented by the organizations listed below, for their hard work and continued support.

Agriculture and Agri-foods Canada
Bird Studies Canada
Central Michigan University
Conservation Ontario
Cornell University
Environment and Climate Change Canada
Fisheries and Oceans Canada
General Dynamics Information Technology
Great Lakes Fishery Commission
Great Lakes Indian Fish & Wildlife Commission
Illinois-Indiana Sea Grant
Indiana Department of Environmental Management
Indiana University
International Joint Commission
Little Traverse Bay Bands of Odawa Indians
Michigan Department of Environment, Great Lakes and Energy
Michigan Department of Natural Resources
Michigan Technological Research Institute
National Oceanic and Atmospheric Administration

Natural Resources Canada
Nature Conservancy Canada

New York Department of Environmental Conservation
Ohio Lake Erie Commission
Ontario Ministry of Northern Development, Mines, Natural Resources, and Forestry
Ontario Ministry of the Environment, Conservation and Parks
Oregon State University
SUNY Brockport
SUNY Buffalo State
U.S. Army Corps of Engineers
U.S. Department of Agriculture Forest Service
U.S. Environmental Protection Agency
U.S. Fish and Wildlife Service
U.S. Geological Survey
University of Minnesota Duluth, Natural Resource Research Institute
University of Minnesota Duluth, Large Lakes Observatory
University of Wisconsin, Green Bay
University of Wisconsin, Milwaukee
University of Wisconsin, Superior
Wildlife Conservation Society Canada