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

Beaver Creek Akron

Analysis Summary for Series #1538

Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)

Metric Name Value Score
MH Total Taxa 30 10
SH Total Taxa 6.5 6.44
MH EPT Taxa 7 5.53
SH EPT Taxa 1 1.5
MH Sensitive Taxa 0 0
SH Ephem % 0 0
SH EPT % 3.02 0.32
SH Chiron % 76.84 2.34
SH Scraper % 4.02 0.9
SH Top3Dom % 91.44 3.29
SH Dom FFG % 83.89 2.68
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 8/12/2013
Sampling Series Series #1538
Drainage Area (mi2) 4.685
Log(DA) 0.670709595223797
Calculation Last Updated 7/22/2025 3:36:16 PM
Sampling Gear LowFlow ArtSub
BMIBI Score
30
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 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:

Northwest Iowa Loess Prairies

This site is in the Northwest Iowa Loess Prairies ecoregion.

Ecoregion Map
Max 88
75th Percentile 58
Median 51
25th Percentile 45
Min 10
This Session's Score 30
Total Reference Site Samples 45
Mean 50.91
Standard Deviation 13.26