1. Relationships between River Environment & Aquatic Life Don Sada Walker Basin Stakeholder Meeting December 12, 2007 Dr. Sudeep Chandra (UNR), Fish Dr. Christian Fritzen (DRI), Periphyton Dr. Kumud Archarya (DRI), Food Webs Ron Hershey (DRI), Water Chemistry

2. Personal Experience  Aquatic Ecologist (30 years) –Understanding relationships between the environment and aquatic communities in West U.S.  High, middle, and low elevation streams, rivers, and spring-fed environments –Fish –Aquatic insects –Mollusks

3. River Goods & Services  Traditional Benefits  Consumption –Irrigation –Transportation –Clean water  Other Benefits –Flood control –Waste purification –Recreation –Wildlife & fish –Food supply

4. Condition of U.S. Rivers PRESETTLEMENT  Free flowing river 3,060,000 Miles 3,060,000 Miles  Number of Dams None None  River Water Quality All Unimpaired All Unimpaired  Extinction Rates 1 sp./million years 1 sp./million years CURRENT  Free Flowing River 600 miles  Number of Dams 75,000 (> 2 m high)  River Water Quality > 33% Impaired  Extinction Rates 123 recorded since 1900 Imperiled or Endangered Imperiled or Endangered - > 25% fish I or E - > 25% fish I or E - > 50% mussels I or E - > 33% crayfish I or E - > 25% amphibians I or E

5. RIVER ENVIRONMENT Nutrients EnergyBenthic Communities Water Column Communities Substrate Composition Hydrograph Turbidity Riparian Communities Geology Gradient

6. River Environment & Aquatic Life  Environment ‘Drives’ Characteristics of Aquatic Life –Temperature –Substrate –Nutrients –Current Velocity –Hydrograph

7. Challenges Challenges  Regional differences –Fish –Macroinvertebrates  Flow –Deserts vs. northeast U.S.  Topography –Mountainous Nevada vs. ‘flat’ east & midwest GENERALITIES FROM ELSEWHERE ARE INAPPROPRIATE FOR NEVADA

8. Regional Context Important One Example Doesn’t Work Everywhere  Management potential  Restoration potential  Hydrograph considerations  Environmental assessment

9. State of Knowledge  Local Context –Few Sites & Sporadic  Fish, East Fork (CDFG) –Macroinvertebrates  East Fork  Historic & scattered through Mason Valley  Watershed Context –Many Sites & Frequent  Water Quality  Flow manipulation  Macroinvertebrates  Fish distribution  Riparian studies  Environment and aquatic life relationships Truckee RiverWalker River REGIONAL INFORMATION MEAGER COMPARED TO OTHERS

10. Walker River Studies Locations  Eight Sites  Base of Sierra Nevada to Lake –East and West Forks –Mainstem

11. Walker River Studies Methods  Quantitatively Describe River Physical Habitat  Quantify Spatial & Seasonal Differences and Variation –Water Chemistry –Aquatic Life  Fish  Macroinvertebrates  Periphyton

12. Products  Determine existing biological and environmental conditions  Understand northern Nevada’s rivers within national context  Provide insight into restoration potential and goals  Inform hydrologic models regarding the consequences of different management decisions