Dr. Ted Sommer

1. Dr. Ted Sommer California Department of Water Resources IEP Pelagic Organism Decline Management Team The Pelagic Organism Decline: An Update

2. Delta smelt Longfin smelt Threadfin shad Striped bass

3. 1970 1970 2000 2000 1980 1980 1990 1990 The Pelagic Organism Decline (POD) Delta Smelt Longfin Smelt Abundance Index Threadfin Shad Striped bass Source: Sommer et al. (2007)

4. POD Management Team Randy Baxter DFG Rich Breuer DWR Larry Brown USGS Mike Chotkowski USBR Matt Nobriga CALFED Marty Gingras DFG Bruce Herbold USEPA Anke Mueller-Solger DWR Ted Sommer DWR Kelly Souza DFG

5. POD Principal Investigators • Dept Fish and Game • Randy Baxter, John Budrick, Kelly Souza, Steve Slater, Kathy Hieb, Marty Gingras • Dept Water Resources • Fred Feyrer, Ted Sommer, Bob Suits, Heather Peterson, Zoltan Matica, Peggy Lehman, Lenny Grimaldo, Mike Mierzwa, Jim Wilde, Karen Gehrts, Tanya Veldhuizen • US Bureau of Reclamation • Mike Chotkowski • US EPA • Bruce Herbold • Consultants • BJ Miller, Bryan Manly • US Fish and Wildlife Service • Gonzalo Castillo, Ken Newman, Scott Foote • US Geological Survey • Joseph Simi, Cathy Ruhl, Pete Smith, Dave Schoellhamer • UC Davis • Bill Bennett, Swee Teh, Inge Werner, David Ostrach, Frank Loge, Jim Hobbs • SF State University • Wim Kimmerer, John Durand • SF Estuary Institute • Daniel Oros, Geoff Siemering, Jennifer Hayworth

6. POD: What We Know NowCaveats • Synthesis is from POD MT, not all PIs. • The story will continue to change. • Most results have not been written up or peer-reviewed. • The management implications of this effort are therefore unclear.

7. TOP-DOWN PHYSICAL & CHEMICAL FISH HABITAT LOSS PARENTS Prior Fish Abundance FISH ABUNDANCE HOME FOOD BOTTOM-UP

8. The ‘Big Three’ Questions • Did anything change at the same time as the Pelagic Organism Decline? • How and why did these factors change? • Did these factors affect populations of pelagic organisms?

9. Quick Answers

10. Prior Abundance PRESENT ABUNDANCE

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

12. Evidence of Allee Effects in Delta Smelt? Juvenile (TNS) Adults (FMWT) Source: Anke Mueller-Solger (DWR)

13. PHYSICAL & CHEMICAL FISH HABITAT FISH ABUNDANCE

14. PHYSICAL & CHEMICAL FISH HABITAT Temperature Turbidity Salinity Nutrients FISH ABUNDANCE Contaminants Disease Toxic algae

15. Habitat Modeling Turbidity Salinity • 40 year data set of fish and water quality. • 100 stations sampled in fall. • Generalized additive modeling approach.

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

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

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 Source: Inge Werner, Swee Teh, and Dave Ostrach (UCD)

19. 2007 Update • Low Flows = Less Dilution • Toxicity and Growth Impairment Seen in Some Invertebrate Bioassays • Ammonia a Rising Concern • Widespread Microcystis Blooms in Summer Source: Inge Werner (UCD), Peggy Lehman and Anke-Mueller Solger (DWR)

20. L55 Fish & zooplankton collection Invertebrate toxicity test sites Sites with invertebrate toxicity in 2007 Jan. – July 2007 Toxicity in the North Delta Inge Werner, UCD

21. Unionized ammonia is toxic to fish Unionized ammonia is calculated from total ammonia, pH, temperature Sacramento at Hood San Joaquin at Stockton

22. ~ 90% of the Ammonium Load at Hood comes from the Sacramento Regional Wastewater Treatment Plant

23. Widespread blooms of the toxic alga Microcystis in 2007 August Levels: 1.3 million cells/mL Core Habitat of Delta Smelt Source: Peggy Lehman (DWR)

24. TOP-DOWN Water Diversions Predation FISH ABUNDANCE

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

26. 80 84 88 92 96 00 04 Evidence of Increased Entrainment of Adult Delta Smelt During Winter 300000 # fish salvaged 0 Source: IEP (2005), Grimaldo (In prep)

27. Increased winter exports Shifts in Tributary Inputs Entrainment Increase in winter salvage.

28. Map of South Delta showing Old and Middle River Flow monitoring stations A Possible Integrator of Delta Water Project Operations: Old and Middle River Flows Old Middle River River Clifton Court Forebay

29. 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

30. Negative Old & Middle River Flows Coincided with Low Smelt Indices in POD Years, But Not in All Previous Years Fall delta smelt index Summer delta smelt index Old & Middle River flows In Log-Linear Modeling Over 1981-2004, Monthly or Semi-Monthly Exports or O&M River Flows Individually Explain No More Than 1.5% Of The Variation In Fall Catches Source: Bryan Manly and Mike Chotkowski (USBR)

31. Bennett Hypothesis: Not All Smelt Are Created Equal Larger/older females: • Have higher fecundity. • Spawn early and repeatedly. • Produce larger/earlier offspring that have higher fitness. • Are more subject to water project effects.