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
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.
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|Blackstripe topminnow Fundulus notatus
||Northern pike Esox lucius
Fish Assemblage and Watershed Condition
Central Corn Belt Plain fish list
- 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 :
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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