Ecological potential of the Grand Calumet River basin

Proceedings of the Indiana Academy of Science, Wntr-Fall, 1999 by Richard L. Whitman, Meredith B. Nevers, Shira Hammann, Philip B. Moy

ABSTRACT

The Grand Calumet River and watershed have been severely degraded by industrialization and urbanization, and yet several high-quality natural areas remain intact. The degraded condition presents numerous opportunities for pollution mitigation and ecosystem restoration. In many areas of the river and watershed, biological communities are characterized by low diversity and pollution-tolerant organisms. By establishing programs of nonnative species control, prescribed burning, sediment removal, wetland establishment and extirpated species re-introduction, the Grand Calumet can be improved to reflect some of its natural history. The dredging plan for the river presents an opportunity to coordinate simultaneous improvement and restoration plans. Possibilities for each section of the river are discussed.

Keywords: Grand Calumet River, Calumet region, restoration, sediment removal

Other papers in this volume discussed the status of each major component of the flora and fauna of the Grand Calumet River study area. Here, we present an executive summary of the restoration opportunities found in the basin. These options were formulated at a meeting of all project authors and represent their collective vision for the Grand Calumet River and its associated ecosystems. This paper also includes a discussion of the impaired uses that serve as the rationale for river dredging as well as a discussion of the ways in which habitat restoration will reduce impairments.

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The solutions were generated with two specific goals in mind. First, the flora, fauna and habitats need to be identified, restored, and protected. Second, pollution in the area needs to be abated. As far as possible, we hope to ensure that the watershed will possess the structural and functional attributes of a native, natural community, consistent with the Lake Michigan dune and swale ecotone.

The first step was to define the area under consideration, recognizing such an area would focus efforts to enhance the region's ecosystems but would not negate efforts to include suitable areas adjacent to the region as they become available. The second step will be to protect and enhance existing high-quality natural areas so that they can serve as biological refugia and as models to guide the restoration projects. Many other areas along the river should be enhanced and restored. These restored areas will serve as buffers for core natural areas and provide migratory pathways between natural and "least" disturbed habitats. Habitat heterogeneity and the control of exotic species are imperative for restoring and managing the watershed. To achieve our long-term goals, partnerships between the private sector and governmental agencies will be necessary to remediate degradation, to provide ongoing stewardship of lands, and to integrate ecological issues into the urban planning process.

THE STUDY AREA

The area covered in this report extends from the first dune ridge south of Lake Michigan to the ridge summit of Toleston Beach (located to the south of the Grand Calumet River) and from the Grand Calumet Lagoons in the east to the river's confluence with the Little Calumet River in Illinois at the western end (Fig. 1). The purpose of our study was to examine functional relationships among habitat areas whose hydrology is connected to and dependent on the Grand Calumet River. Historically, the borders identified for our study marked the extent of the Grand Calumet watershed, but the hydrology of the region has been so altered by human activities that some areas have lost their connection to the river. The greatest focus has been on sites that retain some value as natural areas because these sites will benefit the most from preservation, restoration, and abatement.

The habitat quality along the shore of the Grand Calumet River is highly variable, ranging from contaminated Superfund sites to remnant natural areas that are globally significant for their rarity and diversity. The natural communities of the region were formed as the result of interaction of glacial, biotic, geologic and hydrologic factors. Industrialization has destroyed many of these sites and fragmented the rest, but those that remain retain a surprising degree of species diversity and community integrity.

The communities in the watershed formed through the mixing of species from four different biomes. The tundra species present after glacial retreat were slowly replaced by boreal forest species (Schneider 1989). Gradually, deciduous forest or woodland species replaced the boreal species in a series of changes dependent on the rates of seed dispersal and mobility. A period of warmer and/or drier climate followed, and grassland and savanna communities became established. These species invaded the region in numerous small waves as the glaciers that formed Lake Michigan receded northward (Bacone & Campbell 1983). The current communities reflect these changes. Relict species are still present in areas, but variation has occurred even within historic times. The prime communities in the current natural landscape are upland savannas, prairie remnants, and wetlands. Boreal remnants include bearberry, jack pine, white pine, and paper birch. Some woodland areas are also present. Relicts from other biomes, including tundr a and deciduous forest, are located primarily to the north of the Grand Calumet River (Swink & Wilhelm 1994).