1. Clark Fork Symposium Friday April 24th 2015
Temporal and Spatial Trends of Benthic Biological Integrity in the Upper Clark Fork Basin
Clark Fork Symposium Friday April 24th 2015
Sean P. Sullivan1
Wease Bollman1
Daniel McGuire 2
1 Rhithron Associates, Inc. Missoula, Montana
2 McGuire Consulting, Espanola New Mexico

2. Outline History of benthic community sampling in the Clark Fork Basin.
Current monitoring efforts across multiple agencies.
Trend analysis at sentinel sites in the basin.
Current longitudinal gradient of biological integrity.
Conclusions and future directions

3. 41 years of Bioassessment in the CFR
Community analyses dates back to 1972 ( Canton and Chadwick, 1986*)
Historical data focused on SBC and upper river.
State programs pick up sampling in the early to Mid –eighties
Federal and State programs ‘annually’ to present
*Clark Fork Symposium (1985)

4. More Recent Efforts Federal monitoring program sampling
36 sampling sites from Blacktail Creek to Thompson Falls Reservoir.
State Monitoring Program(s)
15 sites in the CFOU
17 sites in SSTOU

5. Method Heterogeneity Field: Lab: Interpretation:
Quantitative v. semi quantitative
Level of effort
Habitats
Lab:
Subsampling v. whole sample analysis.
Taxonomic targets
Interpretation:
11 historic indices

6. Field Methods/ Lab Methods
4 replicate modified Hess samples ( 0.1m2)
Targeted Riffles
Laboratory
No sub-sampling in Lab
Lowest Practical Taxonomic Level
Hydropsyche ( s.s. and s.l.) to species
Chironomidae- Genus / species grp.
Oligochaeta to Family
10 % Taxonomic and Sorting QC
Synoptic Reference Collections

7. Data Analysis Methods Indices MVFP(Bollman,1998)
MT Foothills (Bukantis, 1998)
B-IBI (Karr,1996)
Montana MMI (Jessup, 2006)
Montana O:E (Hawkins 2006)
Montana O:E (Feldman et al., 2012)
Metals Tolerance Index (McGuire, 1998)
“Hilsenhoff” Biotic Index (McGuire, 1998)
Index of Biological Integrity (McGuire, 1998)
Organic pollution subset
Metals pollution subset

8. Data Harmonization
Field Methods homogenized to 4 replicate modified Hess samples in targeted Riffles.
Laboratory Methods homogenized to full sample identification and enumeration.
Taxonomic harmonization is still in progress with continued QA/QC between analysts.
Interpretation harmonization to McGuire IBI and subsets.

9. Trend Analyses Historical Trend Analysis Spatial Trend
Combine historical and current data
Three ‘sentinel’ locations
Mann – Kendall Non- Parametric Trend Test
Spatial Trend
5 year mean (
10 sites
Silver Bow Creek- Turah
Mann-Kendall Test

10. Trend Analysis- CFR nr. Galen
Extremely weak (R=0.2) but significant upward trends (p>0.01).
2011 decline due to high spring flow scour events?
Observing recovery from more limited recruitment?

11. Trend Analysis Clark Fork at Deer Lodge
Strong positive significant trend over time.
p=>0.01
Recent years have had instream/ near stream construction likely affecting local community.
Limiting factor still appears to be ‘metals’ related.

12. Trend Analysis Clark Fork at Turah
No significant Trend.
p=0.47
All but a few years are un impaired.
Impaired years correlated to Metals impacts

13. Longitudinal Gradient
Map produced by Judy Rosenbaum (RESPEC)

14. Conclusions Temporal Trends:
Upper river trends indicate slow and steady improvement in biotic integrity. Region most susceptible to ‘natural’ disturbance regimes.
Middle river shows strong positive trends in biotic integrity scores. Nutrients and metals still having some effect on community structure.
Lower river shows little improvements, but relatively least impacted reach.

15. Conclusions Spatial Trends No statistically significant trend
Observationally that the river generally improves in biotic integrity with increased distance from “source”.
Mid river shows a decline in IBI scores, further investigation coming in 2015.

16. Discussion
Increased harmonization of monitoring efforts and data in the basin has reduced duplication and increased data compatibility
Refining the tools for measuring biotic integrity.
Re calibration of currently used indices
Use of additional regional indices (O:E) to compare to least impacted streams
Similar analyses with Algal communities
Diatom and Soft bodied algae
Algal biovolume estimates
Nutrient Increaser Taxa ( Teply and Bahls, 2006)