Ecological Risk Assessment
An organized procedure to evaluate the likelihood that adverse ecological effects will occur as a result of exposure to stressors related to human activities, such as the draining of wetlands or release of chemicals.

Ecosystem
A biological community and its environment working together as a functional system, including transferring and circulating energy and matter.

Ecosystem Charter for the Great Lakes Basin
Initiated by the Great Lakes Commission, this is a binational statement of goals, objectives, principles, and action items for the Great Lakes with a plan for achieving it. This non-binding agreement supports a philosophy of ecosystem management that recognizes natural resources as part of a dynamic and complete matrix that pays no heed to political boundaries or jurisdictions. Related Programs - Great Lakes Commission

Ecosystem Indicator
An organism or community of organisms that is used to assess the health of an ecosystem as a whole. For example, the Binational Program has selected the lake trout and Diaporeia (a benthic invertebrate) to be indicator species for Lake Superior. Related Programs - Binational Program

Ecosystem Principles and Objectives for Lake Superior
A binational program described in Volume IV of the Lake Superior Lakewide Management Program. The report lists specific ecosystem principles and objectives for the Lake Superior Basin, provides a set of benchmarks, and helps guide decisions pertaining to land and water management in the Lake Superior ecosystem. Related Programs - Binational Program

Effluent
Liquid wastes that are discharged into the environment as a by-product of human-oriented processes, such as waste material, liquid industrial refuse, or sewage.

Effluent Limitation
Any restriction placed on quantities, discharge rates, and concentrations of pollutants that are discharged from point sources into waters of the United States or the ocean. Related Programs - 40 CFR, Clean Water Act

Endangered Species Act ESA
Federal statutes passed in 1973 that protect endangered and threatened species. The act has 16 sections (16 U.S.C. 1531-1544).

Endangered Species Act Reauthorization ESAR
The name for the federal legislative process to amend the Endangered Species Act. It is anticipated that reauthorization will occur in the mid- to late-1990s.

Environment Canada
The lead federal agency responsible for implementing Great Lakes 2000 and the 1994 Canada-Ontario Agreement respecting the Great Lakes Basin ecosystem. Together, Great Lakes 2000 and the Canada-Ontario Agreement represent the Canadian response to the Great Lakes Water Quality Agreement.

Environmental Impact Assessment EIA
A decision-making process mandated under the National Environmental Policy Act which may require a detailed environmental impact statement analyzing the potential significant environmental impacts and alternatives to the action before the action is permitted. A public comment period takes place on each EIA.

Environmental Impact Statement EIS
A statement detailing the environmental impacts of and the alternatives to an action. See Environmental Impact Assessment.

Environmental Monitoring and Assessment Program EMAP
A federal program initiated by the EPA in 1988 to provide improved information on the current status and long-term trends in the condition of the nation's ecological resources. Seven resource categories are defined: near coastal waters, the Great Lakes, inland surface waters, wetlands, forests, arid lands, and agroecosystems. Related Programs - Environmental Protection Agency

Environmental Protection Agency EPA
A federal agency whose primary goal is to prevent or mitigate the adverse impacts of pollution on human health and the environment.

Environmental Research Laboratory - Duluth ERL-Duluth
See Mid-Continent Ecology Division.

Erosion
The wearing away of the land surface by running waters, glaciers, winds, and waves. Erosion occurs naturally from weather or runoff but can be intensified by land-clearing practices related to farming, residential or industrial development, road building, or timber cutting.

Estuary (Freshwater)
Areas of interaction between rivers and nearshore lake waters, where seiche activity and river flow create a mixing of lake and river water. These areas may include bays, mouths of rivers, marshes, and lagoons. These ecosystems shelter and feed fish, birds, and wildlife. Most importantly, Great Lakes estuaries provide habitat for wildlife and for young-of-the-year and juvenile fish.

Eurasian Ruffe
A non-indigenous species now found in Lake Superior and Lake Huron. This relatively new invader is a member of the perch family. It is usually less than 6 inches long, has a perch-like body shape and is very slimy when handled. This fish may be competing with native perch and other fish for food. There is a great deal of concern over the potential for this fish to expand its range into other North American waters. It has also been called the European ruffe and river ruffe. See also aquatic nuisance species.

Eurasian Watermilfoil
An exotic aquatic macrophyte that forms thick underwater stands of tangled stems and vast mats of vegetation on the surface of inland lakes. In many shallow areas this plant can crowd out native plants and interfere with water recreation such as boating, fishing and swimming. The plant can spread from lake to lake by stem fragments that cling to boats and trailers. Public education campaigns aimed at preventing unintentional transport of the plant by boaters have successfully slowed its spread in some states. See also aquatic nuisance species.

Eutrophic
A term used to classify those lakes of high primary productivity as indicated by high algal concentrations or high nutrient levels. See also eutrophication.

Eutrophication
The process of physical, biological, and chemical changes that occurs in a lake when enriched by nutrients, organic matter, and/or silt and sediments. The process can occur naturally, but if accelerated by human activities such as agriculture, urbanization, and industrial discharge, it is called cultural eutrophication.

Exotic Species
See non-indigenous species.

Exposure
Contact with a chemical or physical agent.

Exposure Assessment
Estimates the amount of a substance something is exposed to.