ICP Detail: U.S. Great Lakes

U.S. Great Lakes System Region 12*

The U.S. Great Lakes System Waterfowl Conservation Region is comprised of five ecoregions designated by the Commission for Environmental Cooperation (IAFWA 1998).

The Prairie Hardwood Transition, Eastern Tallgrass Prairie and the Central Hardwoods Regions include the southern portions of Wisconsin and Michigan, and Northern Illinois, Indiana and western Ohio, was historically a transitional zone between prairie and eastern woodlands, and the primary focus of conservation work within this Conservation Region. Glaciation created numerous pothole type wetlands, shallow lakes, coastal estuaries and river flowages. The Central Hardwoods contains some of the largest and most historically significant wetlands, or remnant wetlands, in the lower 48 states. The area surrounding of Horicon Marsh is remnant glacial habitat and contains numerous pothole-type wetlands. Also important is the Winnebago watershed, consisting of Lake Winnebago and three upstream lakes (Buttes des Mortes, Winneconne, and Poygan). The Prairie Hardwood Transition includes the 12-county area around Chicago, which contains about 60,729 ha of palustrine wetlands, 12,955 ha of lakes, and several resource rich areas as identified by the Illinois Department of Natural Resources (Suloway et al. 1996).


Also within the Prairie Hardwood Transition is the historic Great Black Swamp, which once covered approximately 580 km2 and reached from Sandusky Bay south and west to Fort Wayne, Indiana and north and east to Detroit, Michigan. This system formed on ancient glacial lake plain and was dominated by forested wetlands, with isolated wet prairies and oak savannas interspersed within the swamp and coastal marshes along the Lake Erie shoreline. The Great Black Swamp was decimated in a matter of decades by agricultural drainage and logging efforts and today only fragmented remnants remain (Herdendorf 1987).

The Lake Ontario Basin, in the Lower Great Lakes/St. Lawrence Plain is the lowest in the Great Lakes drainage system, has the highest relief of all the Great Lakes, and is also a primary focus within this Conservation Region. The level plain around the edge of the lake gives way to rolling glaciated topography. Plateaus or glaciated hills with steep slopes comprise the uplands. Streams near the headwaters are fast moving and cold, with high water quality. Bays, river mouths shoreline estuaries, and islands of the St. Lawrence River contain some of the best potential for wetland development in the Great Lakes Region.

The Boreal Hardwood Transition Region includes the northern half of Michigan, Wisconsin and Minnesota, and is characterized by coniferous and northern hardwood forests, numerous clear lakes, bogs, river flowages and nutrient-poor soils. This area includes portions of the Canadian Shield, which encompasses Lake Superior and significant portions of Lakes Michigan and Huron. Over 9,717 ha of coastal wetland, consisting of forested, scrub-shrub, and emergent types, are associated with Wisconsin's Green Bay and the Door Peninsula (Prince et al. 1992), and are considered some of Lake Michigan's most important marshes (Bookhout et al. 1989).

Another notable area of importance in the Boreal Hardwood Transition Ecoregion is the coastal marsh and lake plain region surrounding the Saginaw Bay in Michigan. The 7,287 ha of productive coastal wetlands surrounding Saginaw Bay make up one of the largest remaining freshwater coastal systems in the nation. More than 30 plant and animal species on the federal threatened and endangered list make their home in the 22-county watershed. The area is important for commercial fishing, tourism and recreation as well as being a major agricultural and industrial area.

Wetland Status and Trends

Wetland loss throughout the Prairie Hardwood Transition and Central Hardwoods has been extremely high with most states losing over 75% of their original wetlands (Dahl 1990). Much of the remaining wetland and prairie habitat has been seriously degraded. Threats to wetland habitats of these two regions include water quality, urbanization, recreational development, agricultural drainage, pollution, surface mining, forestry, barge fleeting and high Great Lakes water levels.

Hydrological modification is the key term when characterizing the Prairie Hardwood Transition and Central Hardwoods. Agricultural development has resulted in the conversion of countless small inland wetlands as a result of drainage with millions of kilometers of drain tiles and ditches. Agricultural development has also led to the diking and drainage of Great Lakes coastal marshes, especially along the southern half of Lake Michigan, Western Lake Erie, and Lake St. Clair. "Hardening" of the lakeshore in the late 1880s and early 1900s for agriculture and development do not allow coastal marshes to "migrate" inland in response to high Great Lakes water levels (Herdendorf 1987). In many areas, the only remaining coastal marshes are those retained by waterfowl hunting interests or those located on government-owned wetland management areas. Paradoxically, these existing marshes must be protected and their productivity maintained by dikes and pumps due to the destructive actions of high lake levels, storm events and exotics such as carp, purple loosestrife and phragmites (Kroll and Gottgens 1997).

Almost equally important as hydrological modification, especially along the shore of lower Lake Michigan, the west shore of Lake St. Clair and western Lake Erie, is urban sprawl associated with the cities of Chicago, Detroit and Toledo (Fuller et al. 1995). In many coastal areas, residential and industrial development is so pronounced that wetland restoration on a broad scale is not possible. Small remnant wetlands and isolate "islands" of habitat can be protected and restored, although the overall value for waterfowl is limited. These wetlands can serve as ideal locations for education and public use. Additionally, industrial activity has introduced contaminants into the ecosystem, compounding restoration efforts and presenting a serious issue that must be considered with restoration activities in many areas of this region. Active management of remaining wetlands is especially important because a high level of productivity is necessary to compensate for irreversible wetland losses.

The coastal marshes of the Great Black Swamp are primarily intensively managed marshes due to the hydrological alterations since settlement. Of the 12,146 ha of wetlands remaining, about half are in public ownership and half are owned by private duck hunting clubs (Bookhout et al.1989). Other coastal habitats along the shores of Lake Erie and Ontario have been lost or seriously altered for residential, commercial and recreational development. In addition to this direct loss of habitat, various toxic chemicals from agricultural and industrial sources degrade remaining wetlands. It is expected that coastal shoreline development will increase from 10-30% in many areas in the next 20-50 years.

In the St. Lawrence Valley, dairy farms are the primary industry and the landscape is comprised of an abundance of grassland habitat. However, soils here are low to moderate in productivity and extensive farm abandonment has occurred. Reverting farmland has produced ideal habitat for beaver allowing their populations to expand, creating thousands of acres of wetland habitat. The combination of many wetlands in close proximity to pasture land accounts for relatively significant breeding waterfowl densities. Ironically, the continuing decline in dairy farming in the Valley may present the greatest threat to maintaining and expanding waterfowl production.

An exotic plant, purple loosestrife, is scattered throughout the region. Significant areas of concentration occur at the Montezuma Wetland Complex (MWC), and Tonawanda-Iroquois-Oak Orchard (TIO) wetlands. An intensive biological control program, involving the release of several species of beetles from Europe, has been ongoing on MWC and TIO since about 1995. Results have been very positive and plans are now being made to use beetle populations from these sites to populate other loosestrife-infested areas throughout the region.

In general, wetland loss throughout most of the Boreal Hardwood Transition Ecoregion has been moderate; less than 25% of the pre-settlement wetlands have been lost in the Michigan portion, with similar losses in Wisconsin (Dahl 1990). Although sparsely populated, wetland habitats in this region face numerous human influences including recreational development, urbanization, agricultural drainage, pollution, cranberry operations, peat harvesting and high Great Lakes water levels. Wetland loss in the Saginaw Bay watershed of Michigan, however, has been extreme. Settlement and intensive farming led to the loss and degradation of more than 50% of these wetlands (Comer 1996). Intense agricultural and industrial practices throughout the watershed have seriously degraded the water quality in Saginaw Bay. Similar losses have occurred in the Green Bay and Lake Winnebago areas of Wisconsin.

Waterfowl Characteristics

Breeding Habitat - Mallards, wood ducks, blue-winged teal, ring-necked ducks, mergansers and Canada geese are common breeding species in the U.S. Great Lakes Waterfowl Conservation Region. Nesting by American black ducks, green-winged teal, northern shoveler, gadwall, canvasbacks, redheads and American wigeon also occurs on a limited basis within the region (USFWS 1979). Historically, high numbers of black ducks nested in the Boreal Hardwood Transition region (Pirnie 1935). Mallards are the most common waterfowl species found breeding throughout the entire region. Areas with relatively high populations of breeding mallards occur throughout southeastern Wisconsin, southeastern Michigan, fringes of northern Illinois, Indiana and Ohio, and the St. Lawrence Valley in New York. Survey data taken in New York show that the St. Lawrence Valley has the greatest density of breeding mallard pairs (5\km2) in the entire Northeast portion of the U.S. The wood duck is the second most abundant breeding waterfowl species, and nests throughout the region. Blue winged-teal can also be found nesting where mallards are abundant, but the highest concentrations are in southeast Wisconsin.

The Prairie Hardwood Transition and Central Hardwoods are second only to the prairies to the west in terms of waterfowl production (IAFWA 1998). Glacial pothole wetlands and small inland lakes in the north and forested bottomlands along river corridors provide breeding habitat for dabbling ducks including mallards, wood ducks and blue-winged teal. In Northeast Illinois, mallard breeding pair surveys estimated mallard breeding pair density in a 287,044 ha study area to be 3.38 pairs/km2. Breeding waterfowl densities for all species was approximately 4.6 pairs/sq. km, which compared favorably with areas of secondary importance in the PPR (USFWS 1998). Managed marshes adjacent to vegetated littoral areas of the Great Lakes provide limited nesting habitat for canvasbacks, scaup, mallards, black ducks and red-breasted mergansers (USFWS 1979).

Migration and Wintering Habitat - More than 3 million ducks, primarily mallards, black ducks, lesser and greater scaup, canvasbacks, and redheads are estimated to migrate annually through the Great Lakes region. Many cross the Boreal Hardwood Transition, Central Hardwoods, Prairie Hardwood Transition and the Eastern Tallgrass Prairie as they make their passage between breeding and wintering areas (Bookhout et al. 1989). Important habitats in these regions include portions of the sheltered, vegetated littoral zone of the Great Lakes, coastal marshes, and riverine and palustrine marshes, and adjacent upland habitats of low-gradient river tributaries that empty into the lakes.

Lack of suitable migration habitat, especially for spring migrants, in this Waterfowl Conservation Region may be a factor in population declines of black ducks, canvasbacks, scaup and redheads. Diving ducks, including greater and lesser scaup, canvasback, redhead, bufflehead and common goldeneye generally use open water and emergent marshes associated with coastal wetlands of the upper Great Lakes, Saginaw Bay and Green Bay. Habitat loss and degradation on historic canvasback staging areas, such as the Winnebago System, other large inland lakes, and Green Bay, has caused migrating canvasbacks to utilize the Upper Mississippi River in greater numbers (Bellrose 1976). The Lake St. Clair, Detroit River and southwest Lake Erie marshes are considered to be the most important wetlands in the Great Lakes (Fuller et al. 1995). In recent years, 150,000 canvasbacks have been surveyed in Lake St. Clair (MI DNR unpublished report). The Lake Erie marshes annually host hundreds of thousands of waterfowl in spring and fall, and are the most concentrated staging areas for black ducks in North America (average peak 51,500 black ducks) (Tori et al. 1990).

The Mississippi Valley Population (MVP) of Canada geese, use migration sites in the western Upper Peninsula and eastern Wisconsin. Notably, Horicon marsh in eastern Wisconsin is a significant staging and wintering area for the majority of the MVP geese as they pass through the area. The Saginaw Bay area is a key migration area for the Southern James Bay Population (SJBP) of Canada geese, as it is the first major stop after the birds leave James Bay. It is estimated that during peak fall migration, 13,680 Southern James Bay Canada geese occur annually at Shiawassee National Wildlife Refuge (estimates based on 10-year average). One of the limiting factors for wintering SJBP and other waterfowl in the Saginaw Bay is the lack of an adequate energy source. The Eastern Great Lakes Lowlands is also an important region for the SJBP.

Other Wildlife

This region provides breeding and migration habitat for a diverse group of wildlife including song, shore and upland birds, mammals, fish, amphibians, and reptiles. Species of concern include Forster's, common and black tern, snowy egret; state listed osprey, federally threatened bald eagle and federally endangered piping plover and peregrine falcon. Restoration of wetlands, native grassland complexes, and forested and scrub-shrub habitats will improve breeding and stopover conditions for many birds. Involvement with many "˜all-bird' initiatives associated with the Joint Venture provides additional opportunities to participate in habitat conservation, management and research to improve populations of avian species in North America and the Neotropics. Amphibians use wetlands during part of their life cycle, and while reptiles are often less dependent on wet areas, there are many that require the habitat characteristics provided by wetlands. Wetland-dependent amphibian and reptilian species occurring in the Great Lakes Basin and expected to benefit from wetland restoration include such species of concern as Blanchard's cricket frog, copperbelly rattlesnake, eastern massasauga rattlesnake and Blanding's turtle.

Current Habitat Conservation Programs

This region bridges two Joint Ventures of the NAWMP; the Boreal Hardwood Transition, Central Hardwoods, Prairie Hardwood Transition, Eastern Tallgrass Prairie and the Ohio portion of the Lower Great Lakes/St. Lawrence Plain being associated with the Upper Mississippi River and Great Lakes Region Joint Venture (UMR/GLRJV). Portions of New York and Pennsylvania are in the Atlantic Coast Joint Venture.

In Wisconsin, DU's program is focused in southeastern Wisconsin, which is important for both breeding and migratory waterfowl. Southeast Wisconsin spans an area historically characterized by a glaciated mosaic of wetlands surrounded by tall grass prairie and oak savanna. Agriculture and development are the dominant features resulting in substantial losses of small isolated prairie-like wetlands and the original prairie that covered most of the area prior to settlement. Much of the current landscape is composed of row crops, hayfields, and pasture. Development associated with urban sprawl is currently the greatest threat to grassland and wetland habitat. The protection and restoration of grass and wetland complexes on private land will increase breeding propensity as well as improve production. Coastal habitat restoration and acquisition on large public property is primarily for spring and fall migratory waterfowl, although breeding birds will also benefit from small restoration projects.

Three DU programs cover a significant portion of Lower Michigan: Saginaw Bay, Lake St. Clair/ Lake Erie, and Southeast Lake Michigan including the Grand River. The Saginaw Bay watershed falls mostly within the Boreal Hardwood Transition region. Saginaw Bay is one of largest remaining freshwater coastal systems in the nation. The Saginaw Bay watershed historically contained some of Michigan's most extensive wetlands, providing spring and fall stopover points for tremendous flocks of migrating birds and nesting habitat for large numbers of waterfowl. Settlement and intensive farming led to the loss and degradation of more than 50% of these wetlands. Degradation of remaining habitat has occurred as intense agricultural and industrial practices throughout the watershed have seriously degraded water quality. Conservation work in this area will concentrate on production and migration habitat through the protection and restoration of Great Lakes coastal marshes and their associated habitats, expansion of existing state and federal wildlife areas with the restoration of newly acquired lands, and restoration and enhancement of small wetlands and associated uplands important for waterfowl production on private lands. To date, several NAWCA grants and several large foundation donations have been secured to fund the partnership project in Saginaw Bay.

The St. Clair-Detroit waterway is heavily impacted with over 90% of the U.S. shoreline filled and bulk-headed, that resulted in wetlands being replaced by hardened shoreline. Over 5 million people live within one hour of the area. Despite these impacts, existing marshes in the lower river have high waterfowl use, primarily diving ducks during spring and fall migration as well as wading and shorebirds. The coastal marshes in this area provide habitat for some of the highest concentration of staging American black duck and canvasbacks in North America as well as 27 other species of waterfowl. Because the area still has extensive beds of wild celery, it remains one of the largest and most productive duck feeding and fish spawning grounds in the Midwest. The Western Hemisphere Shorebird Reserve Network as a Regional Shorebird Reserve designated this area. Given the continued threat from sprawl and development, programs in this area will be focused on the long-term protection of important and threatened wetland habitat, primarily for migratory birds.

The southeast Lake Michigan watershed, which includes parts of Indiana, is one of the fastest growing and most urbanized regions in the Great Lakes Basin. This area also supports some of the highest breeding densities of mallards and wood ducks in Michigan. Agriculture and urban development dominate the landscape and have resulted in drained wetlands, fragmented forests, and increased sedimentation and nutrient loading in lakes and streams. Habitat fragmentation, initially for agriculture and more recently for urban development, has hindered attempts to restore large blocks of habitat within this watershed. Wetland losses within the Grand River watershed since 1800 are estimated to be more than 229,000 acres, with some counties exceeding 40-60%. In Indiana, the current landscape contains a disproportionate amount of grass and hence the potential for wetland restoration on private lands is high. The primary life cycle need within this focus area is for breeding habitat, targeted at mallards, and spring migration habitat for a variety of species

DU Programs in the Lake Erie Watershed are focused on southwest Lake Erie marshes in Ohio. Alterations in hydrology are the primary influence on quantity and quality of waterfowl habitat. Sediment from agricultural practices and industrial runoff has created serious water quality problems. The open water bays and coastal wetlands of northwest Ohio are used extensively for feeding and resting by migrating and wintering waterfowl and other wildlife. Remnants of the Great Black Swamp, including inland forested, riverine, emergent and depress ional wetlands and associated uplands, provide valuable habitat for breeding waterfowl. The conservation focus in southwest Lake Erie is restore and preserve forested, inland, and coastal wetlands for breeding, wintering and migratory waterfowl.

Two areas of concentration in the Lower Great Lakes/St. Lawrence Plain of the Lake Ontario watershed include Montezuma and the St. Lawrence Valley. Historically this area was dominated by a forested ecosystem, with extensive coastal marshes. The area has lost approximately 70% of its wetland base primarily due to agriculture and urbanization. The Montezuma Wetland Complex is known as an important stating area within the Atlantic Flyway, attracting as many as 1 million ducks and geese during spring and fall migration. The focus is to restore and protect those areas containing muck land soils that were previously drained for agricultural production. . Three NAWCA grants have been awarded for habitat work in the complex. The St. Lawrence area contains abundant freshwater wetlands interspersed with extensive agricultural grasslands. Although grasslands in this are represent the largest contiguous block of grassed landscape in the northeast U.S., they are currently threatened by farm abandonment which results in natural succession to woody habitat, further fragmentation, and an overall decline in agricultural grasses. This area is an important breeding area for mallards, blue-winged teal, blacks ducks, and Canada geese. Because of the abundance of grasslands, this area supports some of the largest populations of grassland and early success ional bird species in the northeastern U.S. DU has taken the delivery role in "˜All-bird' partnerships in the St. Lawrence. The approach is to develop or protect habitat in a complex of grass and wetlands to meeting multiple lifecycle needs, especially in areas where protected lands already exist so that buffers can be built around these areas.




* Region 12 - NABCI Bird Conservation Regions 12, 13, 22, 23 & 24 Lower Great Lakes / St. Lawrence Plain, Boreal Hardwood Transition, Central Hardwoods, Eastern Tallgrass Prairie, Prairie Hardwood Transition

Revised January 17, 2005 - Region 12

    Major revision and update of all sections