Iowa DNR
BioNet
River & Stream Biological Monitoring
Fish and Benthic Macroinvertebrate Surveys
Physical Habitat Assessments

South Raccoon River Nations Bridge Co Park- Stuart

Analysis Summary for Series #1270

Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)

Metric Name Value Score
MH Total Taxa 47 9.04
SH Total Taxa 11.67 5.14
MH EPT Taxa 24 8.89
SH EPT Taxa 8.33 5.67
MH Sensitive Taxa 10 9.09
SH Ephem % 22.12 2.83
SH EPT % 85.1 8.91
SH Chiron % 11.01 8.99
SH Scraper % 3.32 0.74
SH Top3Dom % 69.67 4.81
SH Dom FFG % 59.97 6.67
MHBI 5.11 7
*Mouse-over metric for full name
**Final IBI is sum of scores multiplied by 0.8333

Analysis Factors

Factor Value
BMIBI Type Warm Water
Sample Date 7/25/2012
Sampling Series Series #1270
Drainage Area (mi2) 330.259
Log(DA) 2.51885466155403
Calculation Last Updated 7/22/2025 3:28:19 PM
Sampling Gear Hess
BMIBI Score
65
Warm Water
Good

BMIBI Score Explained

This site was analyzed using the BMIBI-Warm Water assessment methodology.

Sites that score between 56 - 75 are considered good. A slight reduction in number (Ephemeroptera, Plecoptera, Trichoptera) of taxa; however, good numbers of taxa are present, including several sensitive species, EPT taxa are fairly diverse and dominate the community. The most sensitive taxa and some habitat specialists may not be present and/or are reduced in abundance. The community is balanced, with no taxon excessively dominating in abundance. One functional feeding group, often collector filterers or collector gatherers, may be somewhat dominant.

This location has been classified as a Reference Site. Reference sites represent natural stream qualities that are least disturbed by human activities within the watershed. These sites are then grouped by ecoregion to establish a benchmark against which other streams in the same ecoregion are compared.

EcoRegion Comparison

Scores for a sampling session are compared against reference sites within the same ecoregion:

Rolling Loess Prairies

This site is in the Rolling Loess Prairies ecoregion.

Ecoregion Map
Max 86
75th Percentile 69
Median 61
25th Percentile 54
Min 20
This Session's Score 65
Total Reference Site Samples 127
Mean 61.08
Standard Deviation 10.7