Jump to main content or area navigation.

Contact Us


The Lake

Lake Superior

Lake Superior

Lake Superior is the largest of the Great Lakes in terms of volume. It is also the deepest and coldest of the five. Because of its size, Superior has a retention time of 191 years. Retention time is a measure based on the volume of water in the lake and the mean rate of outflow. Most of the Superior basin is forested, with little agriculture because of a cool climate and poor soils. The forests and sparse population result in relatively few pollutants entering Lake Superior, except through airborne transport [More information | Lake Superior bathymetric map Exit EPA Disclaimer].

To learn more about Lake Superior, visit the Minnesota Sea Grant website. Here you can find more information on life in the lake, including lake facts, articles, podcasts and radio programs relating to Lake Superior and the Great Lakes region. Minnesota Sea Grant Exit EPA Disclaimer.

For more basic information about the Great Lakes including EPA's efforts to protect this natural resource, visit EPA's Great Lakes website

Visualizing the Great Lakes – a collection of photographs from the Great Lakes

Environmental Issues

Learn more about the environmental concerns for the Great Lakes including the pathways for pollution that can negatively impact the Great Lakes, issues such as pathogens, eutrophication and oxygen depletion, toxic contamination, exotic species and air pollution

During the past two centuries, invasive species have significantly changed the Great Lakes ecosystem. In turn, the changes have had broad economic and social effects on people that rely on the system for food, water, and recreation. Lake Guardian workshop participants will be learning about the effects invasive species have had on the Great Lakes area. Learn more about invasive species in the Great Lakes.

Serious problems remain throughout the basin in locations identified as 'Areas of Concern'. Areas of Concern are those geographic areas where beneficial use of water or biota is adversely affected or where environmental criteria are exceeded to the extent that use impairment exists or is likely to exist. The purpose of establishing Areas of Concern is to encourage jurisdictions to form partnerships with local stakeholders to rehabilitate these acute, localized problem areas and to restore their beneficial uses. In these areas, existing routine programs are not expected to be sufficient to restore ecosystem quality to acceptable levels and special efforts are needed. Jurisdictions are implementing Remedial Action Plans (RAPs) to guide specific rehabilitation activities in all 42 areas (one Area of Concern - Collingwood Harbour - has been cleaned up).

Workshop participants will conduct research at the St. Louis River, which is one of the Areas of Concern for the Great Lakes. Learn more about this Area of Concern.

Aboard the Lake Guardian