Monitoring and evaluation of benthic macroinvertebrates in the Big Hole River and tributaries

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2 Monitoring and evaluation of benthic macroinvertebrates in the Big Hole River and tributaries Michael A. Bias Big Hole River Foundation

3 Introduction BMI used to evaluate stream biological health Quantifies attributes of community composition, structural and functional organization into a single number estimate of biological integrity Evaluating the biological integrity of BMI assemblages provides an assessment of environmental quality that can be used to identify limiting factors, for detecting impacts from physical alterations, sediment deposition, nutrients and toxicants, and document successful mitigation of environmental degradation

4 Grayling Grayling of all ages feed opportunistically on drifting invertebrates The feeding behavior of grayling is linked to their pattern of habitat selection Snorkel surveys and tracking tagged fish showed that in the upper Big Hole River basin grayling were unevenly distributed in tributaries, with the majority of bigger grayling being found in lower reaches during the summer (Vatland 2008) Most tagged grayling were documented leaving tributaries for the mainstem river, sometime between late September and early December

5 CCAA Monitoring Efforts Biological fish counts (species, occurrence, and numbers) Habitat (i.e., physical) snowpack, streamflow, thermal conditions, and stream channel morphology Project performance Landowner compliance Bugs?

6 Objectives 2002, Evaluate baseline river health and habitat 2007, Evaluate any change in river health , BMI assemblages are correlated with observed seasonal grayling distributions, and Implemented conservation measures improve stream biological health

7 Sample Locations Governor Miner Crk Rd Miner Crk Rd Miner Little Lake Crk Rd Little Lake Crk Rd Steel Hwy 43 Wisdom Br Rock Crk NFkBHR Mudd Crk Br Fishtrap Hwy 43 Lamarche Hwy 43 Deep Hwy 43 East Bank FAS FAS Jerry Crk Br Maiden Rock FAS Kalsta Br ` ` Notch Bottom FAS High Rd FAS BMI Sample Locations 2002, 2007

8 Sample Locations Governor Miner Crk Rd Miner Crk Rd Miner Little Lake Crk Rd Little Lake Crk Rd Steel Hwy 43 Wisdom Br Rock Crk NFkBHR Mudd Crk Br Fishtrap Hwy 43 Lamarche Hwy 43 Deep Hwy 43 East Bank FAS FAS Jerry Crk Br Maiden Rock FAS Kalsta Br Notch Bottom FAS High Rd FAS BMI Sample Locations 2008, 2009, 2010

9 Follow MT DEQ RBP (Rapid Bioassessment Protocols) 2 traveling kick samples obtained from target riffle habitats at each site Sampling will be conducted 3 times per year (April, July, and October) at each location

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13 Lab Methods RBP III sorting methods employed > 300 organisms per sample 2 stage Identification Samples separated to Order (i.e., Picked ) Further ID d to Genus or species (i.e., taxon)

14 Metrics Taxa richness total number of macroinvertebrate types present in a sample an expression of biodiversity and one of the best estimators of environment health EPT (Ephemoptera Plecoptera Tricoptera) Richness typically the dominant macroinvertebrates in healthy trout streams EPT richness and relative abundance metrics characterize this important component of the benthic fauna Biotic Index developed as a measure of organic pollution this index is an excellent gauge of stresses associated with drought % Dominant Taxa % Collectors % Scrapers and Shredders % Hydropsychinae functional feeding group metrics reflect energy pathways in a stream and, thus, are particular responsive to increased nutrient laden sediment deposition and changes in trophic condition Healthy streams typically have fairly even distributions of feeding groups % EPT

15 Intermountain Valley and Foothill Metric Taxa Richness > < 14 EPT Richness > < 11 Biotic Index < > 6 % Dominant < > 50 % Collectors < > 90 % Scrapers & Shredders > < 10 % Hydropsychinae < > 95 % EPT > < 30 Unimpaired Severely Impaired For each site: score, total, divide by 3, results range 0 1 > 0.75 unimpaired, moderate impaired, < 0.25 severely impaired

16 Where are we at? No Sites No Samples Picked ID d

17 100 % EPT by Site % EPT Site

18 100 % EPT by Site % EPT Site

19 Site No Taxa R EPT R % Dom % EPT % Hydrop Taxa R EPT R % Dom % EPT % Hydrop GC BHR MCR MC BHR LLC SC BHR W RC NFk BHR Mud FT LM DC EB DB JC MR Kal No Hi

20 Site No Taxa R EPT R % Dom % EPT % Hydrop Taxa R EPT R % Dom % EPT % Hydrop GC BHR MCR MC BHR LLC SC BHR W RC NFk BHR Mud FT LM DC EB DB JC MR Kal No Hi

21 1.2 H2O Quality Score by Site H2O Quality Score Site

22 Conclusions Results Preliminary 08: 75% complete 09, 10 yet to ID % EPT Tributaries, except RC, unimpaired Most mainstem sites improved (unimpaired) compared to 02 H2O Quality Scores Revealing different results than EPT FT, DC, LM largely unimpaired; SC moderately impaired Most mainstem scores declined from 02 to 08 Drought conditions through the decade? Results preliminary BMI monitoring and evaluation can contribute substantially to the monitoring objectives of the CCAA to help recover fluvial Arctic grayling Excellent tool for monitoring health of the river throughout the system

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