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Some of Michigan’s most important natural
resources are often overlooked: Great Lakes coastal wetlands.
These unique habitats are integrally tied to the health and
diversity of the Great Lakes ecosystem.
Coastal wetlands provide important ecological
functions and critical habitat for fish, birds and wildlife. Because
of these features, coastal wetlands offer a variety of educational
opportunities.
They are one of the most valuable shore
types in the Great Lakes, says Michigan Sea Grant Extension Agent
Walter Hoagman, and yet these coastal ecosystems are often under-appreciated.
“Michigan has the most extensive
system of coastal wetlands of any Great Lakes state,” says
Hoagman. “They’re an invaluable part of the Great Lakes
coastal zone.”
Wetland Types and Ecological Functions
Within the Great Lakes basin, there are many wetlands that are
directly connected to the Great Lakes, with water levels that
vary with lake levels.
These are generally considered coastal
wetlands. Thousands of additional wetlands are near the Great
Lakes but not hydrologically connected.
There are at least six types of Great Lakes
coastal wetlands. Among them are lagoon and barrier (the most
common), ridge and swale, shoreline, embayed, riverine and delta
wetlands.
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| Blue Harebells grow along the wetlands
of Thunder Bay Island's coast. Photo by Dave Brenner MSG |
Wetlands have specific zones, among them are the aquatic (open
water) zone, the emergent zone, wet meadow, shrub, and the upland
or swamp forest zone. Typical plants in each zone are specially
adapted to survive different degrees of root saturation and changing
conditions.
All of these coastal wetlands provide key ecological functions.
Notably, wetlands help improve water quality by absorbing nutrients
and some chemicals, and filtering sediments. For example, wetlands
might trap agricultural fertilizers from runoff, transforming
and releasing nutrients gradually into the Great Lakes.
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