Middle Fork Project AQ 3 Macroinvertebrate and Aquatic Mollusk Technical Study Report Overview

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Middle Fork ProjectAQ 3 Macroinvertebrate and
Aquatic Mollusk Technical Study Report Overview

• April 21, 2008

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Study Objectives

• Document the BMI community in the peaking reach
  and compare to adjacent bypass and comparison
  reaches to characterize general habitat
  conditions.
• Sample the BMI community at long-term USDA-FS
  sampling sites to supplement existing data sets.
• Document BMI community in bypass reaches
  downstream of each large reservoir.

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Study Objectives

• Document the BMI community in areas with known
  water quality issues, if any, as determined in
  the AQ 11 TSR.
• Document the seasonal density and size
  distribution of drifting macroinvertebrates in
  selected bypass reaches and the peaking reach for
  input to bioenergetics growth and habitat
  modeling (2009 AQ 5-TSR).
• Determine presence or absence of 3 special-status
  mollusk species and identify potentially suitable
  habitat for these species (2009 AQ 3-TSR).

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Macroinvertebrate Study Objectives and Related
Study Elements and Reports
Study Objectives Document BMI community in the
peaking reach and compare to adjacent bypass and
comparison reaches to characterize general
habitat conditions. Sample BMI community at
long-term USDA-FS sampling sites to supplement
existing data sets. Document BMI community in
the bypass reaches downstream of each large
reservoir. Document BMI community in areas with
known water quality issues, if any are identified
in the AQ 11 - TSP. Determine presence or
absence of three special-status mollusk species
and identify potentially suitable habitat for
these species. Document seasonal density and
size distribution of drifting macroinvertebrates
in selected bypass reaches and the peaking reach
for input to bioenergetics growth and habitat
modeling.
Conduct 2007 Field Surveys
Conduct SWAMP Benthic Sampling
Conduct CSBP Benthic Sampling at the Ralston
Afterbay Sediment Management Project Monitoring
Sites
Conduct Drift Sampling
Document 2007 Findings in this Macroinvertebrate
Report
Consult with Aquatic TWG
Discuss Contingency Sampling Based on Water
Quality Results
If Necessary, Develop Recommendations and Prepare
Contingency Studies
Document 2007 Findings in the Bioenergetics
Report (2009)
Complete 2008 Mollusk Field Studies and
Contingency Studies (if necessary)
Document 2008 Mollusk and Contingency Study
Results in Macroinvertebrate Report (2009)
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Macroinvertebrate Study Sites
14 SWAMP Sites 7 RASMP (CSBP) Sites
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BMI Metrics

• Multi-metric index of biotic integrity (IBI)
  (Rehn 2008)
• ET taxa richness
• Percent intolerant individuals
• Percent tolerant individuals
• Percent Non-insect taxa
• Percent predator individuals
• Percent scraper individuals
• Shannon diversity

• Individual metrics consistent with the RASMP
  (2000-2006)
• Invertebrate density
• Taxa richness
• EPT ratio
• Percent Chironomidae
• California Tolerance Value
• Functional feeding groups
• Dominant taxa

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Survey Results

• Longitudinal Trends in BMI Community Metrics
• Comparison of Peaking Reach and Adjacent Bypass
  and Comparison Reaches
• Above and Below Diversions
• Bypass Reaches Below Large Reservoirs
• Long-term BMI Sampling Sites

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Longitudinal Trends in BMI Community Metrics

• Hydropower IBI scores are higher at higher
  elevation and colder water sampling sites than at
  the low elevation and warmer water sampling
  sites.

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Comparison of Peaking Reach with Adjacent Bypass
and Comparison Reaches

• Hydropower IBI and individual metric scores in
  the peaking reach (RM 20.9 to RM 4.8) are similar
  to sites in the Middle Fork American and Rubicon
  Rivers immediately upstream of Ralston Afterbay
  and comparison streams, although some variability
  of individual metrics occurs.

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Comparison of Peaking Reach with Adjacent Bypass
and Comparison Reaches

• Compared to the comparison sampling sites, the
  downstream peaking reach sampling sites had
• Lower California Tolerance Values (better
  habitat)
• Similar or higher BMI densities
• Similar EPT Index values
• Slightly lower taxa richness
• More collector-gathers and collector-filterers
  and fewer scrapers

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Comparison of Peaking Reach with Adjacent Bypass
and Comparison Reaches

• Hydropower IBI scores and individual metrics are
  low at MF24.4 and MF36.2 compared to adjacent
  bypass and comparison sites.

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Above and Below Diversions

• In 2007, hydropower IBI scores were slightly
  higher upstream from the diversions than
  downstream.

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Bypass Reaches Below Large Reservoirs

• Hydropower IBI scores are high and within the
  range of those observed in unimpaired river
  reaches above hydropower reservoirs by Rehn
  (2008).

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Long-term BMI Sampling Sites

• RASMP Locations (2000-2007)

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Long-term BMI Sampling Sites

• RASMP Locations (2000-2007) Functional Feeding
  Groups

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Long-term BMI Sampling Sites

• South Fork Long Canyon Creek

• Hydropower IBI scores have slightly increased
  since 1999.

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Long-term BMI Sampling Sites

• Duncan Creek

• Hydropower IBI scores have varied over time.