South Fork Chariton River Corydon
Analysis Summary for Series #1265
Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)
| Metric Name | Value | Score |
|---|---|---|
| MH Total Taxa | 35 | 7.6 |
| SH Total Taxa | 5 | 2.74 |
| MH EPT Taxa | 4 | 1.85 |
| SH EPT Taxa | 1.67 | 1.35 |
| MH Sensitive Taxa | 2 | 2.06 |
| SH Ephem % | 5.38 | 0.69 |
| SH EPT % | 5.73 | 0.6 |
| SH Chiron % | 85.41 | 1.47 |
| SH Scraper % | 2.34 | 0.52 |
| SH Top3Dom % | 94.25 | 1.06 |
| SH Dom FFG % | 94.29 | 0.95 |
| MHBI | 6.13 | 3.22 |
| *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 | 9/12/2012 |
| Sampling Series | Series #1265 |
| Drainage Area (mi2) | 37 |
| Log(DA) | 1.56820172406699 |
| Calculation Last Updated | 7/22/2025 3:27:58 PM |
| Sampling Gear | ArtSub |
Sessions used in this analysis
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 | 78 |
| 75th Percentile | 58 |
| Median | 52 |
| 25th Percentile | 42 |
| Min | 14 |
| This Session's Score | 20 |
| Total Reference Site Samples | 49 |
| Mean | 49.84 |
| Standard Deviation | 13.11 |