MONROE, Mich. – Honking geese soar overhead in a V-formation, buffeted by bitter gusts off nearby Lake Erie, while flocks of mallards bob along the shore. Even blanketed in snow, the sprawling wetland in southeastern Michigan is a magnet for water birds – one reason a public-private project is underway to improve it.
Crews are building levees, canals and pumps that will regulate water levels and upgrade fish passageways in a 946-acre section of Erie Marsh, making it a better home for wildlife and limiting the spread of invasive plants.
It’s an example of decades-old efforts by government agencies and private groups to rebuild Great Lakes coastal wetlands such as swamps, bogs and marshes that have been depleted by development. A federal report released in November suggests the work is beginning to pay off.
The eight-state Great Lakes region – extending from western New York to eastern Minnesota– was the only section of the U.S. where coastal wetland acreage increased during a five-year period when scientists took extensive measurements with satellites and field photography.
The gain was modest – 13,610 acres, an area not quite as large as the New York City borough of Manhattan. Yet it happened as the rest of the nation’s coastal wetlands shrank by 360,720 acres. The loss amounted to less than 1 percent of the U.S. total, but continued a longtime negative trend.
Wetlands are immensely valuable, helping prevent floods by absorbing excessive rainwater.
They are known as nature’s kidneys, filtering out pollutants that otherwise would wash into lakes and rivers, and also provide vital wildlife habitat – nesting grounds for ducks and geese, temporary refuges for migratory birds and spawning areas for fish.
Scientists say the continental U.S. has lost roughly half the wetland acreage that existed before the European settlement era. They’ve been relentlessly filled and drained for farms, housing and cities.
Replacing wetlands is a primary goal of an Obama administration program called the Great Lakes Restoration Initiative that is focusing on the region’s biggest environmental problems. Separately, the U.S. and Canada signed an agreement last year to upgrade the lakes’ water quality that calls for boosting wetlands.
Experts say the gains in the Great Lakes region reflected in the study resulted partially from a prolonged drop in water levels, which created new wetland areas as vegetation sprouted along shorelines in places that had been submerged.
Some of that acreage could disappear if the lakes rise again in coming years, said Tom Dahl, a scientist with the U.S. Fish and Wildlife Service and one of the report’s authors.
Great Lakes coastal wetlands also face continuing development threats. Many are along shorelines that would be prime locations for hotels or condominiums.
Regulations designed to protect them have drawn legal challenges from critics who say they stifle economic growth and violate property rights.