Thompson Fork - Grand River Davis City
Analysis Summary for Series #1348
Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)
| Metric Name | Value | Score |
|---|---|---|
| MH Total Taxa | 28 | 5.38 |
| SH Total Taxa | 4.67 | 2.06 |
| MH EPT Taxa | 15 | 5.56 |
| SH EPT Taxa | 2.33 | 1.59 |
| MH Sensitive Taxa | 3 | 2.73 |
| SH Ephem % | 0.88 | 0.11 |
| SH EPT % | 3.83 | 0.4 |
| SH Chiron % | 85.31 | 1.48 |
| SH Scraper % | 0.28 | 0.06 |
| SH Top3Dom % | 97.64 | 0.37 |
| SH Dom FFG % | 96.16 | 0.64 |
| MHBI | 6.27 | 2.7 |
| *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 | 7/19/2012 |
| Sampling Series | Series #1348 |
| Drainage Area (mi2) | 701 |
| Log(DA) | 2.84571801796666 |
| Calculation Last Updated | 10/10/2025 8:07:47 AM |
| 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 | 78 |
| 75th Percentile | 58 |
| Median | 52 |
| 25th Percentile | 42 |
| Min | 14 |
| This Session's Score | 19 |
| Total Reference Site Samples | 49 |
| Mean | 49.84 |
| Standard Deviation | 13.11 |