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Glossary of technical terms
    that appear in the LaMPs

Acronyms | Words and definitions

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Small organisms that do not have spinal columns; may filter bottom sediments and water for food. Animals without backbones ("invertebrates") that are large enough to be seen with the naked eye ("macro"). Examples of macroinvertebrates include: crayfish, snails, clams, aquatic worms, leeches, and the larval and nymph stages of many insects, including dragonflies, mosquitoes, and mayflies. Macroinvertebrates are excellent indicators of water quality because they cannot move to a different section of water if the water they are in is uninhabitable.


Plants of lakes, streams and wetlands that are visible with the naked eye. This term literally means "large plant." Usually refers to rooted, seed-producing aquatic plants.

Management Measures (MM)

A management measure is an economically achievable way to control the addition of pollutants from existing and new nonpoint sources. These measures call for the best available nonpoint pollution control practices, technologies, processes, site specific criteria, operation methods, or other alternatives.

Mass Balance

A scientific approach that studies the sources, movement, and destination of any substance, for example a contaminant, that enters a lake system. A mass balance budget for a particular pollutant is the amount that enters a lake minus the amount that is tied-up in the sediment, broken down by chemical or biological processes, or removed by some other means. This should equal the amount that flows out of the lake system. This exercise enables scientists to assess the possible long-term effects of a pollutant and possible remediation actions. Also see "Lake Michigan Mass Balance Study," "Great Lakes Toxic Reduction Effort," "Lakewide Management Program."

Means Subgoal

Means subgoals describe the natural (ecological) and organizational processes required to achieve end point subgoals. Also see "End point subgoals."

Mercury (Hg)

A heavy metal, mercury is a neurotoxin that is toxic if breathed or ingested at sufficiently high concentrations. Mercury is present naturally in the environment. It has commonly been used in a wide variety of applications including thermometers, fluorescent bulbs, mirrors, hide preservation, paints, plastic coloring, inks and stains, and golf course pesticides. Because of its common use, mercury is released during garbage incineration. It is also released through the combustion of fuels such as coal and wood for energy production. Mercury readily bioaccumulates in all aquatic organisms, especially fish and shell fish and in humans and wildlife that consume fish. Many lakes in the Great Lakes region have fish consumption advisories due to high levels of mercury primarily caused by atmospheric deposition. Also see "Fish Consumption Advisories" and "Remedial Action Plans."

Mercury Deposition Network

The objective of the Mercury Deposition Network is to develop a national database of weekly concentrations of total mercury in precipitation and seasonal and annual flux of total mercury in wet deposition. The data will be used to develop information on spatial and seasonal trends in mercury deposited to surface waters, forested watersheds, and other sensitive receptors.


Refers to a lake with relatively moderate amounts of nutrients (phosphorus and nitrogen) in its surface water. The trophic state of a lake that is in between eutrophic and oligotrophic. Also see "Etutrophic" and "Oligotrophic."

Metric Tonne

Unit of weight used in Canada equal to 1,000 kilograms or 2,246 pounds. Equivalent to 1.102 U.S. tons.

Michigan Department of Agriculture

The Michigan Department of Agriculture sponsors programs for aerosol container recycling, groundwater stewardship, and pollution prevention in farming.

Michigan Department Environmental Quality (MDEQ)

Michigan administers many programs (similar to U.S. EPA's) for protection of water quality in ground water and surface waters, including the NPDES permit program, water quality standards regulations, the nonpoint source pollution program, and ambient statewide monitoring programs. Michigan DEQ focuses on environmental regulatory, permitting, and related enforcement functions. The MDEQ is participating in the development of the LaMP for the state of Michigan.

Michigan Department of Natural Resources (MDNR)

The MDNR is responsible for the stewardship of Michiganís natural resources and for the provision of outdoor recreational opportunities since creation of the original Conservation Department in 1921. The MDNR focuses on promoting diverse outdoor recreational opportunities, wildlife and fisheries management, forest management, state lands and minerals, state parks and recreation areas, conservation, and law enforcement.

Microbial contaminant

Any micro-organisms (bacteria, viruses, and protozoa such as cryptosporidium) that can cause disease.


A naturally-occurring, potent liver toxin produced by the algae Microcystis.


A blue-green algae that causes algae blooms under eutrophic, high phosphorus conditions. It can be toxic to aquatic life and humans if ingested in sufficient quantities due to the presence of microcystin.

Mid-Continent Ecology Division (MED)

The EPA's freshwater ecology and water pollution research laboratory in Duluth, Minnesota. Established in 1967, the lab develops methods for predicting and assessing the effects of pollutants on freshwater resources. It is also involved in Great Lakes research, such as work in food chain contaminants, modeling, coastal wetlands, and the Environmental Monitoring and Assessment Program. MED was formerly called the Environmental Research Lab-Duluth.

Minnesota Acid Deposition Control Act

A Minnesota law passed in 1982 that required the MPCA to (1) identify the areas of the state containing resources sensitive to acid deposition, (2) develop a standard to protect these resources, (3) adopt a control plan to reduce sulfur dioxide emissions, and (4) ensure that all Minnesota emission sources subject to the control plan were in compliance by January 1, 1990.

Minnesota Air Toxics Strategy

A program developed by the Minnesota Pollution Control Agency to help achieve smooth, fair implementation of air toxics provisions of the 1990 Clean Air Act Amendments, protection of public health and the environment, and the collection of air toxics information. The strategy mirrors the federal program somewhat, but has not gone through rule-making. It is a shift in focus for the state away from air toxics rules.

Minnesota Department of Health (MDH)

The state agency responsible for human health protection in Minnesota. Among other duties, the MDH prepares the fish consumption advisory each year and establishes drinking water standards.

Minnesota Department of Natural Resources (MN DNR, DNR)

A Minnesota state agency responsible for the management of the state's timber, waters, minerals, and wildlife. The Department is organized by division according to the resources it manages: forestry, fish and wildlife, parks and recreation, minerals, trails and waterways, enforcement, and waters.

Minnesota Environmental Response and Liability Act (MERLA)

This Minnesota state legislation was patterned after the Comprehensive Environmental Response, Compensation, and Liability Act, and provides the state with the authority to deal with uncontrolled releases of hazardous substances to the environment.

Minnesota Interagency Exotic Species Task Force Committee

Established by Minnesota state legislation in 1989, this task force established a state-wide communications network between agencies that are involved with regulations, management, research, technical assistance, public awareness, and educational programming regarding potential and existing exotic species.

Minnesota Pollution Control Agency (MPCA, PCA)

A Minnesota state agency responsible for setting standards and authorizing permits for air quality, solid waste, hazardous waste disposal, water quality, and noise pollution. The focus of the MPCA is on compliance to these standards through technical assistance, education, and information. The agency is organized into four major divisions: air quality, water quality, ground water and solid waste, and hazardous waste.

Minnesota Sea Grant (Sea Grant)

This University of Minnesota-based program supports research, extension, and education about Lake Superior, the other Great Lakes, and inland waters of Minnesota, making research accessible to citizens, resource managers, and policy makers.

Minnesota Toxic Pollution Prevention Act (TPPA)

State legislation passed into law in 1990, this act creates policies and sets up ways to prevent the release of toxic pollutants into the environment by reducing or eliminating toxic pollutants at their source through pollution prevention (P2).

Mixing Zone

A limited area or volume of water where initial dilution of a point source pollutant discharge takes place. The zone is extended to cover the secondary mixing in the surrounding waterbody. Numeric water quality criteria can be exceeded, but acutely toxic conditions are prevented from occurring in this zone. Also see "Clean Water Act," "National Pollutant Discharge Elimination System."

Multimedia Inspections

These are inspections of a dischargerís effect on water and air quality and the generation of solid waste.

Multimedia Risk

The human health risk due to exposure to a pollutant through all pathways, such as inhalation, ingestion, or skin contact.

Municipal Industrial Strategy for Abatement (MISA)

A program initiative of the province of Ontario intended to reduce water pollution.


A substance that is known or suspected to cause mutations.


A permanent change in the hereditary material involving a physical change in chromosomes or genes.

Mysis relicta

Freshwater shrimp found primarily in the Great Lakes. A primary food source of lake trout.

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