Unnamed Tributary to Tarkio River Stanton (HW104)

Analysis Summary for Series #1548

Benthic Macroinvertebrate Index of Biotic Integrity (BMIBI)

Metric Name	Value	Score
MH Total Taxa	31	10
SH Total Taxa	13.67	10
MH EPT Taxa	9	7.14
SH EPT Taxa	9.33	10
MH Sensitive Taxa	3	5.45
SH Ephem %	48.92	6.26
SH EPT %	90.46	9.47
SH Chiron %	6.04	9.49
SH Scraper %	5.85	1.31
SH Top3Dom %	65.68	10
SH Dom FFG %	53.93	7.68
MHBI	5.58	5.26
*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	8/6/2013
Sampling Series	Series #1548
Drainage Area (mi²)	4.631
Log(DA)	0.665674780993893
Calculation Last Updated	7/22/2025 3:36:46 PM
Sampling Gear	Surb

Sessions used in this analysis

BMIBI Score

Warm Water

Excellent

BMIBI Score Explained

This site was analyzed using the BMIBI-Warm Water assessment methodology.

Sites that score between 76 - 100 are considered excellent. High numbers of taxa present, including sensitive species, EPT taxa are diverse and dominate the community in terms of abundance; habitat and trophic specialists (e.g., Scraper organisms) are present in good numbers, all of the major functional feeding groups (FFG) are represented, with no particular FFG that is excessively dominant. The community has good balance in terms of the abundance of organisms in each taxon.

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:

Steeply Rolling Loess Prairies

This site is in the Steeply Rolling Loess Prairies ecoregion.

Max	72
75th Percentile	61
Median	53
25th Percentile	47
Min	28
This Session's Score	77
Total Reference Site Samples	37
Mean	53.73
Standard Deviation	10.44