Great Lakes Ecoregion

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Great Lakes ecoregion

This lake system contains the largest supply of freshwater in the world.

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Education

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Great Lakes

freshwater

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water

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Keep exploring

Find even more resources on the Great Lakes ecoregion in our searchable resource database.

Lesson plans & activities Teaching Great Lakes science (ES, MS, HS) offsite link Freshwater fish life cycle (ES, MS) offsite link Nab the Aquatic Invader interactive (ES, MS, HS) offsite link The Medicine Chest (HS) offsite link How well do you know the Great Lakes? (ES, MS, HS) offsite link Freedom Seekers: The Underground Railroad, Great Lakes, and science literacy activities (MS/HS) offsite link Multimedia How great are the Great Lakes? (video) Great Lakes photo gallery Great Lakes webcams Data resources Interactive Great Lakes chemical and human interaction data Great Lakes real time hazards Great Lakes forecast data Rip current forecast Searchable invasive species database Great Lakes bathymetry maps Lake level viewer Great Lakes MODIS Imagery Region Map National Data Buoy Center Background information The formation of the Great Lakes offsite link Great Lakes food web diagrams Career resources An interview with Great Lakes Environmental Research Laboratory Biologist Dave Fanslow offsite link Related stories NOAA teams up with cruise company for Great Lakes research (2020) Searching for WWII-era aircraft lost in the Great Lakes (2020) Giant sinkholes are adding water to Lake Huron. Scientists ask: How much? (2019) NOAA’s lake level viewer for the Great Lakes (2013) More Collections Watersheds, flooding, and pollution The water cycle

The Great Lakes system includes five large lakes, one small lake, four connecting channels, and the St. Lawrence Seaway. The large lakes are Superior, Michigan, Huron, Erie, and Ontario. They hold about 90% of the freshwater in the United States and approximately 20% of the world's freshwater supply. Forty million residents of the United States and Canada depend on this system for clean drinking water.
A satellite image of the great lakes with little cloud cover.

SeaWiFS satellite captured this view of the Great Lakes, including the turbid waters of Lake Erie, in this recent overpass. (Image credit: Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE)

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Keep exploring

Find even more resources on the Great Lakes ecoregion in our searchable resource database.

Lesson plans & activities Teaching Great Lakes science (ES, MS, HS) offsite link Freshwater fish life cycle (ES, MS) offsite link Nab the Aquatic Invader interactive (ES, MS, HS) offsite link The Medicine Chest (HS) offsite link How well do you know the Great Lakes? (ES, MS, HS) offsite link Freedom Seekers: The Underground Railroad, Great Lakes, and science literacy activities (MS/HS) offsite link Multimedia How great are the Great Lakes? (video) Great Lakes photo gallery Great Lakes webcams Data resources Interactive Great Lakes chemical and human interaction data Great Lakes real time hazards Great Lakes forecast data Rip current forecast Searchable invasive species database Great Lakes bathymetry maps Lake level viewer Great Lakes MODIS Imagery Region Map National Data Buoy Center Background information The formation of the Great Lakes offsite link Great Lakes food web diagrams Career resources An interview with Great Lakes Environmental Research Laboratory Biologist Dave Fanslow offsite link Related stories NOAA teams up with cruise company for Great Lakes research (2020) Searching for WWII-era aircraft lost in the Great Lakes (2020) Giant sinkholes are adding water to Lake Huron. Scientists ask: How much? (2019) NOAA’s lake level viewer for the Great Lakes (2013) More Collections Watersheds, flooding, and pollution The water cycle

How the Great Lakes formed

During the last ice age, the mile-thick Laurentide ice sheet covered most of Canada and the northern contiguous United States. The massive weight and movement of this glacier gouged out the earth to form the lake basins. About 20,000 years ago, the climate warmed and the ice sheet retreated. Water from the melting glacier filled the basins offsite link, forming the Great Lakes. Approximately 3,000 years ago, the Great Lakes reached their present shapes and sizes. Today, the Great Lakes ecoregion contains a variety of habitats, including aquatic, forest, marsh, wetland, and dune ecosystems. Widely varying climate, soils, and topography support more than 3,500 species of plants and animals.

Murky water flows under a culvert. Kids Creek project restores habitat and food sources for Great Lakes fish

A NOAA-supported project in Traverse City, Michigan, is helping enhance habitat and food sources for fish like brook trout.

Humans and the Great Lakes

Humans are also part of the Great Lakes system. Commercial and sport fishing, agriculture, recreation, tourism, manufacturing, and shipping are all important to the region. These activities create jobs and provide goods and services. The fishing industry extracts millions of pounds offsite link of fish per year from the lakes. Farmers within this watershed produce corn, soybeans, hay, milk, and other food products. The area is also known for its industry that produces steel, chemicals, and other products. The shipping opportunities in the Great Lakes played a critical role in settlement of the region and development of industry. Today more than 200 million tons of cargo pass through its waters each year.

Aerial view of Belle Isle in the Detroit River. Habitat restoration in the Great Lakes: By the numbers

NOAA’s habitat restoration work in the Great Lakes strengthens healthy fisheries and ecosystems, benefits local economies, and supports resilient communities.

Threats to the Great Lakes

Threats to the Great Lakes' ecosystems, include invasive species, climate change, pollution, and habitat destruction. Climate change affects water temperatures, weather patterns, and lake levels. Pollutants from residential, agricultural, and industrial areas reduce water quality. Land development decreases the amount of wildlife habitat. Fish populations have been declining offsite link in recent years as a result of these threats and increased fishing pressure.

The Lake Huron shoreline at Tawas Point, Michigan. This area is part of the Great Lakes Coastal Wetlands Resilient Lands and Water Partnership. History and economy of the Great Lakes region

Ever since Thunder Bay National Marine Sanctuary was designated in 2000 as the first national marine sanctuary in the Great Lakes, staff and partners have undertaken several expeditions to search for shipwrecks, and have even discovered some that were lost for decades. Probably one of the most notable discoveries within the sanctuary since designation is that of the steamer Choctaw (1892-1915) and wooden bulk freighter Ohio (1873-1894) in historic shipping lanes off Presque Isle, Michigan in Lake Huron.

EDUCATION CONNECTION

The Great Lakes Literacy Principles offsite link provide a framework for educators teaching about the Great Lakes, helping teachers and students think about the Great Lakes as a system, rather than a set of unrelated parts. Thinking systemically can provide a greater understanding and help identify solutions to the issues threatening the region.

Keep exploring

Find even more resources on the Great Lakes ecoregion in our searchable resource database.

Lesson plans & activities Teaching Great Lakes science (ES, MS, HS) offsite link Freshwater fish life cycle (ES, MS) offsite link Nab the Aquatic Invader interactive (ES, MS, HS) offsite link The Medicine Chest (HS) offsite link How well do you know the Great Lakes? (ES, MS, HS) offsite link Freedom Seekers: The Underground Railroad, Great Lakes, and science literacy activities (MS/HS) offsite link Multimedia How great are the Great Lakes? (video) Great Lakes photo gallery Great Lakes webcams Data resources Interactive Great Lakes chemical and human interaction data Great Lakes real time hazards Great Lakes forecast data Rip current forecast Searchable invasive species database Great Lakes bathymetry maps Lake level viewer Great Lakes MODIS Imagery Region Map National Data Buoy Center Background information The formation of the Great Lakes offsite link Great Lakes food web diagrams Career resources An interview with Great Lakes Environmental Research Laboratory Biologist Dave Fanslow offsite link Related stories NOAA teams up with cruise company for Great Lakes research (2020) Searching for WWII-era aircraft lost in the Great Lakes (2020) Giant sinkholes are adding water to Lake Huron. Scientists ask: How much? (2019) NOAA’s lake level viewer for the Great Lakes (2013) More Collections Watersheds, flooding, and pollution The water cycle Back to top

Tag » How The Great Lakes Were Formed