Wetlands aid in flood control, shoreline stability and provide diverse wildlife habitat
By Garret Ellison
The Grand Rapids Press
LANSING, Mich. (AP) — When 19th century surveyor Lucius Lyon first clapped eyes on Michigan, he excitedly wrote his friends back east to tell of a pristine wilderness that had been “undervalued” by a poor 1815 report.
“Michigan has been considered but little better than the waste land of the United States, but when the country was explored and surveyed... it was found to possess as good a soil and greater advantages than the famed Ohio.”
At the time of Lyon’s 1822 letter, there was about 10.7 million acres of wetlands across Michigan, then just a territory of the expanding United States. Today, nearly 200 years later, that acreage has dropped to about 6.4 million.
According to a new report authored by Chad Fizzell at the Michigan Department of Environmental Quality, Michigan has lost more than 4.2 million acres of wetlands to farming and development since European settlement began in the early 1800s.
Ducks Unlimited helped the state with the National Wetland Inventory update, according to The Grand Rapids Press.
Most of that loss occurred prior to 1978, a year before the state passed the Geomare-Anderson Wetlands Protection Act, a strong law that partially resulted in Michigan becoming the first state in the U.S. to receive delegated authority to regulate most wetlands and streams considered “Waters of the U.S.” and approve or deny wetland development permits on behalf of the federal government.
Michigan’s total wetland loss since 1978 is estimated at 41,000 acres, with the rate of decline slowing since then. Unfortunately, the inventory data is at least a decade old, collected in 1978, 1998 and most recently in 2005.
Nonetheless, the report says about 17 percent of the state is covered by wetlands, which act as a kind of natural biological water filter that aids in flood control, shoreline stability and provides diverse wildlife habitats.
Between 1998 and 2005, about 8,000 acres of wetland were lost. The loss rate during that period was about 1,150 acres per year, down from about 1,600 acres per year between 1978 and 1998.
The rate of decline has tapered, but not abated, the report notes.
“However, while state wetland regulations have helped to slow the destruction of wetlands in Michigan from a quantitative perspective, watershed related wetland studies completed around the state have consistently shown a decrease in wetland function and overall quality for the wetlands that remain.”
The state’s diverse geography, which includes large industrial areas near Detroit, miles of freshwater shoreline and huge tracts of forest in Northern Michigan, has resulted in higher wetland losses in certain areas.
— Upper Peninsula: 17 percent loss (638,000 acres).
— Northern Lower Peninsula: 20 percent loss (387,000 acres).
— Southern Lower Peninsula: 66 percent loss (3,320,000 acres).
— Great Lakes coastal wetlands: 71 percent loss.
“Overall, trends show a substantial loss in coastal wetlands from historic estimates, but also indicate significant variability due to (Great Lakes) water level fluctuations.”
The largest type of state wetland, about 70 percent, is the Palustrine forest, a non-tidal wetland type covered with trees, shrubs, moss and other vegetation. Most bogs, swamps, floodplains and marshes are part of the category.
Authors note some limitations in the report. Some large wetland areas being actively farmed may have been missed or under-represented by the aerial imaging analysis. Also, some smaller wetland tracts hidden by forest canopy or “which fall on the drier end of the hydroperiod or water regime spectrum” may have been omitted.
“Unfortunately, one of the wetland types that may fall into this particular class of omission is vernal pools, a particularly diverse habitat that supports an array of salamanders, frogs, and turtles and provides foraging areas for many neotropical birds.”
A new aerial inventory is expected to finish in 2016, according to the report. Improving technology and high-resolution topographic imaging called LiDAR — which can penetrate tree canopies — could “could redefine wetland and hydrologic mapping.”
Authors conclude that “wetland resources continue to be depleted at a rate that, while slowing, is still faster than efforts to restore or create wetlands” and areas with loss are struggling with water quality, flooding, flashy streams and wildlife declines.
“In addition, Michigan’s wetlands continue to face increasing threats, including historic threats such as agriculture and development, as well as new threats like invasive species and climate change.”
