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

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

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)

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

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

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

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

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.

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 ( 2010-2014 10 sites Silver Bow Creek- Turah Mann-Kendall Test

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?

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.

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

Longitudinal Gradient Map produced by Judy Rosenbaum (RESPEC)

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.

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.

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)