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

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

Fish Facilities Provide Data on Numbers Salvaged Up to Percent of Delta Inflow Water Project Losses

Striped Bass Delta smelt Longfin smelt Winter Salvage (Nov-Mar) Threadfin Shad 250,000 2,500,000

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

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

Mean Values for December-March Negative Old & Middle River Flows Apparently Increase Adult Delta Smelt Entrainment Source: Source Lenny Grimaldo (In Review) r 2 = 0.31, p<0.05 Delta Smelt SWP & CVP Salvage (log count) Combined Old & Middle River Flow (cfs)

“First Flush/turbidity spike” Winter 14 days of OMR cfs

Spawning (temp<12 C) Late Winter-Spring OMR to cfs

Downstream Movement (temp C) Spring OMR to cfs

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

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

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

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

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

b a Where the smelt are in the bay

Other habitat stressors Bioassays showed little effect (<5 %) in 2005 or <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)

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

~ 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

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

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

Alternative Life Histories FallWinterSpringSummer Liberty Island % catch 40 0

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

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

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

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

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

Striped Bass Revisited

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

What Happened To All Of The Mamas? Percent Females Gill Net Sampling

Effect of Sex Shift on Population? Petersen Estimates Adults

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

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