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

Indian Creek Lewis (RMN Trend Site)

Analysis Summary for Series #2839

Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)

Metric Name Value Score
MH Total Taxa 25 4.81
SH Total Taxa 9.33 4.11
MH EPT Taxa 12 4.44
SH EPT Taxa 7 4.76
MH Sensitive Taxa 2 1.82
SH Ephem % 26.29 3.36
SH EPT % 92.25 9.66
SH Chiron % 2.86 9.81
SH Scraper % 0 0
SH Top3Dom % 57.52 6.74
SH Dom FFG % 68.25 5.29
MHBI 5.44 5.78
*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 8/29/2024
Sampling Series Series #2839
Drainage Area (mi2) 182.745
Log(DA) 2.26184550326538
Calculation Last Updated 7/22/2025 3:37:33 PM
Sampling Gear Surb
BMIBI Score
50
Warm Water
Fair

BMIBI Score Explained

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

Sites that score between 31 - 55 are considered fair. Total taxa richness and EPT (Ephemeroptera, Plecoptera, Trichoptera) taxa richness are noticeably reduced from optimum levels; sensitive species and habitat specialists are rare; EPT taxa are still dominant in abundance; however, the most-sensitive EPT taxa have been replaced by ept taxa that are more tolerant of organic enrichment; the community is not well-balanced; a few taxa clearly dominate in abundance, collector-gatherers or collector-filterers often comprise more than 50% of the community.

This location has been classified as a Candidate Reference Site. Further study is required to determine if this site represents natural stream qualities that are least disturbed by human activities within the watershed.

EcoRegion Comparison

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

Steeply Rolling Loess Prairies

This site is in the Steeply Rolling Loess Prairies ecoregion.

Ecoregion Map
Max 72
75th Percentile 61
Median 53
25th Percentile 47
Min 28
This Session's Score 50
Total Reference Site Samples 37
Mean 53.73
Standard Deviation 10.44