Indiana Biological Survey

Division of Fishes Projects

Central Corn Belt Plain Ecoregion

Central Corn Belt Plain sites

Dunes Creek, Indiana

Dead River, Illinois

The Central Corn Belt Plain (CCBP) consists of dissected glacial till mantled with loess (Omernik and Gallant 1988). Much of the ecoregion is characterized by low relief; however, some morainal hills occur in the northern portion reaching 60.1 m. Stream valleys are generally shallow throughout the 46,400 square miles of the ecoregion. Small streams have narrow valley floors; larger streams have broad valley floors. Elevation varies from about 121 m in the southern portion of the ecoregion to over 303 m on a few of the hills in the north. Precipitation occurs mainly during the growing season and averages from 80-176 cm annually. Except near Lake Michigan and in the meandering corridors along major rivers, few natural lakes occur.

Both perennial and intermittent streams are common in the ecoregion. Constructed drainage ditches and channelized streams further assist in soil drainage in flat, poorly drained areas (e.g., claypans). Stream density is approximately one mile per square mile in the most typical portions of the ecoregion, but ranges from one to two miles per square mile in the “generally typical” portions of the ecoregion.

Major crops produced in the CCBP are corn, soybeans, feed grains, and some livestock forage. Emphasis on livestock production is not as great as the adjacent ecoregions. Approximately, five percent of the ecoregion remains as woodland, primarily on wet floodplains, steeply sloping valleys, and morainal ridges.

Most of the soils of the Central Corn Belt ecoregion developed under tall grass prairie. They are dark and fertile soils comprised of Hapludolls and Argiudolls on loess-covered till. Argiaquolls, Haplaquolls, and Ochraqualf’s occur on broad, flat uplands, especially in the claypan region. Fragiaqualf’s and Hapludalf’s are locally common on forested slopes and loessal ridges. Hapludolls, Haplaquolls, Udifluvents, and Fluvaquents are common on the poorly drained silt and clay alluvium on floodplains. A few Haplaquolls and Medisaprists have formed in poorly drained flats and wet depressions.

The natural vegetation of the area consisted of a mosaic of bluestem prairie and oak/hickory forest. Most of the level uplands and broad floodplains were covered by tall grasses: big and little bluestem, indiangrass, prairie dropseed, and switchgrass. Hardwood forest originally occurred along the irregular topography of streams and moraines. Woodlands were originally a mixture of oak and hickory species including, black oak, white oak, bur oak, red oak, shingle oak, shagbark hickory, and bitternut hickory, with occasional black walnut, yellow popular, white ash, sugar maple, basswood, elm, and beech. Riparian areas represent the remaining refugia for pin oak, silver maple, elm, ash, cottonwood, willow, sycamore, and sweetgum in the heavily agricultural area. Cattails, bulrushes, and common reed grow in the organic soils of the marshes.

Blackstripe topminnow Fundulus notatus	Northern pike Esox lucius

Fish Assemblage and Watershed Condition

• Kankakee River Drainage:

  We sampled 112 sites mostly from 1990-1995. A total of 82 species were collected and were numerically dominated by cyprinid species. The headwaters of the Kankakee River were depauperate of cyprinids, and instead were comprised of other benthic insectivores.

  The overall water quality of the Kankakee River ranges between very poor ( IBI score 12; numerous sites) to excellent (IBI score: 57, Yellow River). An increasing trend was evident from headwater to higher order tributaries in the overall water quality of the Kankakee drainage. The number of sites approximated a normal distribution based on the integrity of sites sampled during 1990. The following was the range of conditions (N=112 sites) within each condition class: excellent 1.78% (2 sites), good 16.07% (N=18), fair 36.6% (N= 41), poor 28.57% (N=32), very poor 16.07% (N=18), no fish 0.89% (N=1).

• Iroquois River Drainage:

  The Iroquois River was sampled at 37 headwater and wadeable sites. A total of 56 species were collected and were numerically dominated by catfish species. The headwaters of the Iroquois River, i.e., Oliver Ditch and Ryan Ditch, were depauperate of cyprinids, but instead possessed catfish and centrarchid species. The areas were generally degraded due to fluctuating flows and prohibited few species from maintaining permanent residence.

  The overall condition of the Iroquois River ranged from a low of very poor (IBI score: 16; single site) to a high of excellent (IBI score: 56; single station). The integrity of the Iroquois River drainage did not vary with increasing drainage area and showed a normal distribution of condition. The following was the percent occurrence of site conditions: excellent 5.41% (N=2), good 29.73 (N=11), fair 45.95% (N=17), poor 16.22% (N=6), very poor 2.7% (N=1). Fish were collected from every site in the Iroquois River drainage. Poor habitat conditions were pervasive throughout the drainage, which contributed to the condition of the fish assemblage. Channelization and side-cast dredging of single banks reduced habitat complexity. There were several high quality streams in the drainage including Sugar Creek, Curtis, and Carpenter Creeks, which had high IBI scores at almost every site sampled.

  The red shiner Cyprinella lutrensis was collected in high numbers in most of the ditches that drain into the Iroquois River.

• Lake Michigan Basin :

  Two divisions are recognized within the Lake Michigan basin, including the East Branch Little Calumet River and the Lake Michigan Divisions. The East Branch Little Calumet River Division includes Burns ditch, the East Branch Little Calumet River and its tributaries (i.e., Salt Creek, Reynold’s Creek, and the unnamed tributary in the headwaters). A total of 28 headwater and wadeable sites were sampled in the Little Calumet Division, which had integrity scores ranging from very poor (IBI score = 12; three sites) to fair (IBI score= 45; single site). The biological integrity of the Little Calumet River declines with increasing drainage area and has a skewed condition distribution. The following was the percent occurrence of East Branch Little Calumet Division sites within condition class: fair 14.29% (N=4 sites), poor 46.43% (N=13), very poor 39.29% (N=11). Fish were collected at all sites in the Division. Reynold’s Creek was an exceptional stream in the Division, as well as, the unnamed tributary in the headwaters of the Little Calumet.

  Species appearing in the Division included Atlantic salmon Salmo salar, which either emigrated through Lake Michigan stocking efforts or was transplanted. New drainage records include the American brook lamprey Lampetra appendix and the largescale stoneroller Campostoma oligolepis.

  The Lake Michigan Division includes the Grand Calumet River drainage, the West Branch Little Calumet River and its tributaries, all former coastal wetlands of Lake Michigan. Twenty headwater and wadeable sites were sampled and 36 species of fish were collected. There were no outstanding reference conditions remaining in this drainage. The condition of the Lake Michigan Division ranged from very poor (IBI score=12) to fair (IBI score=44; single station). The condition distribution was highly skewed showing a decline in biotic integrity with increasing drainage area. The following was the condition of the fish assemblage in the Lake Michigan Division: fair 5.0% (N=1), poor 10.0% (N=2), very poor 85.0% (N=17). Fish were collected at all sites in the Division. Sites that had low index values were due to poor habitat and toxic influence. Several tributaries had low flows that caused accumulation of soft substrates and effectively reduced available habitat.

Back to top