Big Muddy Creek Spencer
Analysis Summary for Series #1542
Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)
| Metric Name | Value | Score |
|---|---|---|
| MH Total Taxa | 20 | 3.92 |
| SH Total Taxa | 8.33 | 4.1 |
| MH EPT Taxa | 7 | 2.93 |
| SH EPT Taxa | 5.33 | 3.84 |
| MH Sensitive Taxa | 2 | 1.85 |
| SH Ephem % | 15.2 | 1.94 |
| SH EPT % | 27.56 | 2.89 |
| SH Chiron % | 68.59 | 3.17 |
| SH Scraper % | 6.77 | 1.51 |
| SH Top3Dom % | 88.06 | 1.94 |
| SH Dom FFG % | 80.23 | 3.29 |
| MHBI | 5.62 | 5.11 |
| *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 | 8/27/2013 |
| Sampling Series | Series #1542 |
| Drainage Area (mi2) | 63.018 |
| Log(DA) | 1.79946461586834 |
| Calculation Last Updated | 7/22/2025 3:36:28 PM |
| Sampling Gear | ArtSub |
Sessions used in this analysis
Warm Water
Poor
Artficial substrates were poor in quality due to little to no flow. A beaver dam was present downstream of the reach, and compounded the issue.
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 Reference Site. Reference sites represent natural stream qualities that are least disturbed by human activities within the watershed. These sites are then grouped by ecoregion to establish a benchmark against which other streams in the same ecoregion are compared.
EcoRegion Comparison
Scores for a sampling session are compared against reference sites within the same ecoregion:
| Max | 84 |
| 75th Percentile | 67 |
| Median | 59 |
| 25th Percentile | 50 |
| Min | 10 |
| This Session's Score | 30 |
| Total Reference Site Samples | 173 |
| Mean | 57.64 |
| Standard Deviation | 13.14 |