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

Wapsipinicon River Troy Mills (REMAP #65)

Analysis Summary for Series #688

Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)

Metric Name Value Score
MH Total Taxa 35 6.73
SH Total Taxa 7 3.08
MH EPT Taxa 10 3.7
SH EPT Taxa 4.33 2.95
MH Sensitive Taxa 4 3.64
SH Ephem % 2.07 0.26
SH EPT % 7.89 0.83
SH Chiron % 76.65 2.36
SH Scraper % 1.18 0.26
SH Top3Dom % 95.31 0.74
SH Dom FFG % 92.13 1.31
MHBI 6.21 2.93
*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 9/24/2003
Sampling Series Series #688
Drainage Area (mi2) 1218.788
Log(DA) 3.08592816957473
Calculation Last Updated 7/22/2025 3:39:33 PM
Sampling Gear ArtSub
BMIBI Score
24
Warm Water
Poor

BMIBI Score Explained

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

Sites that score between 0 - 30 are considered poor. Severely impaired macroinvertebrate community. Low numbers of taxa present, sensitive species not present, EPT taxa are rare or not present; community extremely unbalanced; dominated by a few pollution tolerant organisms; some trophic functional feeding groups are not represented. Total numbers of organisms may be low. Total taxa richness and EPT taxa richness are noticeably reduced from optimum levels; sensitive species and habitat specialists are rare; EPT taxa no longer dominate the macroinvertebrate community. Taxa that are tolerant of organic enrichment and/or excessive sediment loads are dominant; the community is unbalanced; a few generalist taxa make up a high percentage of the organisms present; collector-gatherers or collector-filterers are very dominant.

This location has been classified as a survey site. Survey sites are compared to reference sites within the same ecoregion. A reference site represents natural stream qualities that are least disturbed by human activities within the watershed. Reference sites are grouped by ecoregion to establish a benchmark against which these survey streams are compared.

EcoRegion Comparison

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

Iowan Surface

This site is in the Iowan Surface ecoregion.

Ecoregion Map
Max 91
75th Percentile 75
Median 66
25th Percentile 57
Min 23
This Session's Score 24
Total Reference Site Samples 162
Mean 65.27
Standard Deviation 12.31