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

Unnamed Tributary to Elk Creek Gillett Grove - Fen Valley WMA (HW116)

Analysis Summary for Series #1541

Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)

Metric Name Value Score
MH Total Taxa 22 9.23
SH Total Taxa 14 10
MH EPT Taxa 6 5.25
SH EPT Taxa 6 10
MH Sensitive Taxa 2 4.05
SH Ephem % 10.18 1.3
SH EPT % 58.76 6.15
SH Chiron % 1.7 9.93
SH Scraper % 20.57 4.6
SH Top3Dom % 61.03 10
SH Dom FFG % 48.58 8.57
MHBI 5.43 5.81
*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 9/24/2013
Sampling Series Series #1541
Drainage Area (mi2) 3.513
Log(DA) 0.545678149792026
Calculation Last Updated 7/22/2025 3:36:25 PM
Sampling Gear Surb
BMIBI Score
71
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 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:

Des Moines Lobe

This site is in the Des Moines Lobe ecoregion.

Ecoregion Map
Max 84
75th Percentile 68
Median 59
25th Percentile 51
Min 10
This Session's Score 71
Total Reference Site Samples 161
Mean 58.18
Standard Deviation 13.09