East Nishnabotna River Shenandoah
Analysis Summary for Series #2407
Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)
| Metric Name | Value | Score |
|---|---|---|
| MH Total Taxa | 25 | 4.81 |
| SH Total Taxa | 5.67 | 2.5 |
| MH EPT Taxa | 11 | 4.07 |
| SH EPT Taxa | 4.33 | 2.95 |
| MH Sensitive Taxa | 3 | 2.73 |
| SH Ephem % | 1.5 | 0.19 |
| SH EPT % | 18.4 | 1.93 |
| SH Chiron % | 81.31 | 1.89 |
| SH Scraper % | 0.3 | 0.07 |
| SH Top3Dom % | 97.33 | 0.42 |
| SH Dom FFG % | 82.2 | 2.97 |
| MHBI | 5.85 | 4.26 |
| *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 | 8/12/2020 |
| Sampling Series | Series #2407 |
| Drainage Area (mi2) | 1021.794 |
| Log(DA) | 3.00936334816564 |
| Calculation Last Updated | 7/22/2025 3:33:09 PM |
| Sampling Gear | Float ArtSub |
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:
| Max | 72 |
| 75th Percentile | 62 |
| Median | 53 |
| 25th Percentile | 46 |
| Min | 28 |
| This Session's Score | 24 |
| Total Reference Site Samples | 39 |
| Mean | 53.74 |
| Standard Deviation | 10.33 |