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New Science – New Regulations

New Science – New Regulations. Bruce Herbold (EPA) IEP and POD Management Teams. Fall abundance in 2008 continued low for all POD fishes. Source DFG 2008 Fall MW Trawl No sampling 1974 and 1979. TOP-DOWN. Water Diversions. Predation. PHYSICAL & CHEMICAL FISH HABITAT.

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New Science – New Regulations

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  1. New Science – New Regulations Bruce Herbold (EPA) IEP and POD Management Teams

  2. Fall abundance in 2008 continued low for all POD fishes. Source DFG 2008 Fall MW Trawl No sampling 1974 and 1979

  3. TOP-DOWN Water Diversions Predation PHYSICAL & CHEMICAL FISH HABITAT Prior Fish Abundance FISH ABUNDANCE Temperature Turbidity Salinity Contaminants Disease Food availability Food quality Toxic algae SAV BOTTOM-UP

  4. Water Project Losses Up to 35-65 Percent of Delta Inflow Fish Facilities Provide Data on Numbers Salvaged

  5. 94 96 98 00 02 04 Winter Salvage (Nov-Mar) Longfin smelt Delta smelt Striped Bass 250,000 Threadfin Shad 2,500,000

  6. Fall abundance in 2008 continued low for all POD fishes. Source DFG 2008 Fall MW Trawl No sampling 1974 and 1979

  7. Old River Middle River Old and Middle Rivers as an Integrator of Hydrodynamic Effects

  8. Negative Old & Middle River Flows Apparently Increase Adult Delta Smelt Entrainment 1993-1999 2000-2005 r2 = 0.31, p<0.05 Delta Smelt SWP & CVP Salvage (log count) Combined Old & Middle River Flow (cfs) Mean Values for December-March Source: Source Lenny Grimaldo (In Review) 1993-2005

  9. “First Flush/turbidity spike” Winter 14 days of OMR -2000 cfs

  10. Spawning (temp<12 C) Late Winter-Spring OMR -3500 to -5000 cfs

  11. Downstream Movement (temp 12-25 C) Spring OMR -1250 to -5000 cfs

  12. Rearing ( about 1 ppt salinity) Fall Typical Distribution Wet year outflow 7000-11,000 cfs Source: Sommer et al. In review

  13. TOP-DOWN Water Diversions Predation PHYSICAL & CHEMICAL FISH HABITAT Prior Fish Abundance FISH ABUNDANCE Temperature Turbidity Salinity Contaminants Disease Food availability Food quality Toxic algae SAV BOTTOM-UP

  14. Fall “habitat quality” deteriorated Striped bass Delta smelt Source: Feyrer et al. (CJFAS 2007)

  15. Fall “habitat quality” matters to the delta smelt population Fall EQ + Fall Abundance predicts juvenile production

  16. Increased outflow = more longfin smelt. Pre-clam Upper Estuary – relation changed Post-clam POD years Fall Midwater Trawl Lower Estuary – relation unchanged Bay Study Otter Trawl Source: Randy Baxter, DFG

  17. Where the smelt are in the bay a b

  18. Other habitat stressors • Bioassays showed little effect (<5 %) in 2005 or 2006. • <15% adult delta smelt impaired • 100 % of young striped bass show multiple infections • Little evidence of toxicity Source: Inge Werner, Swee Teh, and Dave Ostrach (UCD)

  19. POD & Nutrients • Example: Ammonia pollution Sewage Treatment Plants Increasing Ammonia levels in Delta and Suisun Bay Potential Ecosystem Effects

  20. ~ 90% of the Ammonia Load at Hood comes from the Sacramento Regional Wastewater Treatment Plant Sources: A. Mueller-Solger, DWR; A. Jassby, in press SFEWS

  21. Widespread blooms of the toxic alga Microcystis in 2007 August Levels: 1.3 million cells/mL Microcystis grows well on ammonia! (Diatoms don’t) Core Habitat of Delta Smelt Source: Peggy Lehman (DWR)

  22. July August 2007 Microcystis bloom and smelt effects L55 Fish & zooplankton collection August Microcystis bloom Sept delta smelt distribution

  23. Liberty Island 40 % catch 0 Fall Winter Spring Summer Alternative Life Histories

  24. A Major Emphasis on Habitat Restoration to Boost the Delta Food Web FISH ABUNDANCE Food availability Food quality BUT… only local effect likely BOTTOM-UP

  25. TOP-DOWN Water Diversions Predation PHYSICAL & CHEMICAL FISH HABITAT Prior Fish Abundance FISH ABUNDANCE Temperature Turbidity Salinity Contaminants Disease Food availability Food quality Toxic algae SAV BOTTOM-UP

  26. But Recent Levels Were Not Remarkable Food Affects Summer Smelt Survival Delta Smelt Zooplankton (Jul-Oct) Source: Wim Kimmerer (In review)

  27. POD Years Stock - Recruitment Effects Threadfin shad Juvenile Production Delta smelt

  28. Have Delta Smelt Dropped Below Critical Population Levels? Juvenile (TNS) Recent Trend Adults (FMWT) Source: Anke Mueller-Solger (DWR)

  29. Striped Bass Revisited

  30. What’s Wrong With This Picture? Juveniles Age-O Townet index Adults Adults Adult abundance (1000)

  31. What Happened To All Of The Mamas? 40 Gill Net Sampling 30 Percent Females 20 10

  32. Effect of Sex Shift on Population? Petersen Estimates Adults

  33. Effect of Sex Shift on Population? Petersen Estimates Adults Gill Net Sex Ratio Applied to Petersen Estimates Adults

  34. Highly variable Lots Little Cool Low Low High Flow Phosphorus Ammonia Temperature Contaminants “Harvest” turbidity Clams Jellyfish Edge and benthic fish Microcystis Aquatic Weeds Low and Constant Limited Lots Warm High High Low Diatoms Pelagic fish Natives thrive Resists invasions

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