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Coastal Wetlands: highly dynamic ecosystems, aesthetic marvels
May 19, 2022
As part of American Wetlands Month, MI Environment features a story from the State of the Great Lakes report.
The Great Lakes are beloved by many people and in many ways define the quality of life for Michiganders. Michigan is the only state nestled in the center of a freshwater ecosystem that accounts for 20% of the planet’s fresh surface water.
Boaters, swimmers, hunters, anglers, artists, birdwatchers and people of all walks of life come to the shores of these lakes to add value to their lives in many ways. The coastal marshes, dune and swale complexes, Lakeplain prairies and fens that speckle the coasts of these wonderful lakes are havens for fish and wildlife, as well as for the many people who love to enjoy the serenity of these unique systems.
What is a Coastal Wetland?
Wetlands are areas where water covers the soil or is present either at or near the surface of the soil all year or for varying periods of time during the year. Commonly referred to as bogs, swamps or marshes, wetlands support certain kinds of vegetation or aquatic life. Coastal wetlands, found throughout the shores of the Great Lakes region, are biological sanctuaries, unique and highly dynamic ecosystems and aesthetic marvels. They are essential to the health of the Great Lakes.
Benefits of Coastal Wetlands
Wetlands are considered valuable because they clean the water, recharge water supplies, reduce flood risks and provide fish and wildlife habitat. In addition, wetlands provide recreational opportunities, aesthetic benefits and commercial fishery benefits. Extremely biologically productive, they serve as spawning and nesting habitat for many of Michigan’s fish, wildlife, migratory birds and waterfowl. Marsh and wetland vegetation anchors sandy shorelines during high water periods, protecting the shoreline from the erosive impacts of the waves and ice of the Great Lakes.
How Coastal Wetlands change
Coastal wetlands are ever-changing, responding to changes in water levels, weather patterns and surrounding landscape impacts every year. Great Lakes water levels fluctuate as part of a natural cycle over time, and coastal wetlands respond to water level changes in many ways. During periods of higher water, many of the coastal wetlands transition into sparsely vegetated or submerged aquatic beds. During periods of lower water, many coastal wetlands transition into densely vegetated wet meadow and emergent communities, often expanding to cover the wide sections of exposed lake bottomlands.
Threats to Coastal Wetlands
Threats to coastal wetlands include climate change, invasive species, shoreline hardening, development, nutrient and pollutant inputs from runoff and others. Despite their highly adaptable characteristics, the quality of coastal wetlands continues to be degraded because of these factors.
Loss of Great Lakes Coastal Wetlands
Michigan has over 275,000 acres of Great Lakes coastal wetlands but has lost approximately 50% of the coastal wetlands that existed prior to European settlement. In some parts of the state, losses are as high as 90%.
Great Lakes Coastal Wetland Monitoring Program
The Great Lakes Coastal Wetland Monitoring Program (CWMP) began in 2011 and is continuing a successful basinwide Great Lakes coastal wetland monitoring program using a scientifically-validated sampling design for plants, invertebrates, fish, amphibians, birds and water quality. The CWMP is a long-standing partnership between 15 organizations throughout the Great Lakes basin, led by Central Michigan University and funded by the U.S. Environmental Protection Agency. Field crews from the research organizations sample approximately 1,000 coastal wetlands every five years, providing a significant and continuous dataset for coastal wetland in a continuous time period. The results of this project are also used to inform planning and evaluation of wetland restoration projects throughout the Great Lakes region.
Caption: Coastal wetland in Delta County on Lake Michigan where black tern nest monitoring takes place. Shown is Joe Kaplan of Common Coast Research. (Photo courtesy of DNR.)