1. Digital Map from Dr. William Bowen California State University Northridge Sacramento- San Joaquin Delta San Joaquin River Sacramento River Suisun Bay San Francisco 1

2. 2

3. Stationary Habitat ---Geometry Dynamic Habitat --- Hydrodynamics, ocean conditions, weather Environment Biological Conditions 3

4. Estuarine habitat conceptual model (Peterson 2003) Stationary Habitat Dynamic Habitat Production Area Tidal and River Flow Pelagic Recruitment 4

5. Hydrology Delta Geometry Water Demand Exports Delta Hydrodynamics Realized Habitat Potential Habitat Biological and Chemical Conditions 5 Tides

6. Variability of Freshwater Delta Inflow 6

7. X2=82 X2=70 7

8. Pelagic organisms follow salinity: The copepod Eurytemora affinis Kimmerer 1998 8 X2 (km)

9. 1:1 Pelagic organisms follow salinity: Delta smelt 9

10. Most fishes follow salinities Kimmerer 2004 Marine species 10

11. 1967-87 1988-2000 1982-2000 (DS) All Years High FlowLow Flow Source: Kimmerer 2002MEPS Higher trophic levels show many relationships of abundance to freshwater flow 11 X2 (km)

12. High FlowLow Flow Lower trophic levels show few relationships of abundance to freshwater flow Source: Kimmerer 2002 MEPS 1972-1987 1988-2000 12 X2 (km)

13. 1873 Delta: Long residence time Marsh connections Two rivers connect to bay Waterways dendritic 13

14. Modern delta Short residence times Rip-rapped Cross Delta flows Rare San Joaquin connection to bay Waterways web-like 14

15. What Changes As Flow Increases? X2 Location of Any Salinity Range LSZLSZ Salinity and X2 FLOW 15 stratification

16. Floodplains Proportion Diverted What Changes As Flow Increases? Delta Residence Time River Stage, Velocity River stage and velocity Floodplain inundation 16 FLOW Upstream bottom current

17. Nutrients Contaminants Organic matter Sediment What Changes As Flow Increases? Concentrations Loadings 17 FLOW

18. What Changes As Flow Increases? Adult spawners move up: Salmon Green and White Sturgeon Longfin smelt Delta smelt Splittail American shad Pacific herring Young Marine fish move up: Starry flounder White croaker Pacific halibut Young fish move down: Salmon Longfin smelt Delta smelt Splittail American shad Striped bass 18

19. 19 Flows are important but so is geometry

20. 1. Environmental flows are more than just volumes of inflows and outflows 2. Recent flow regimes both harm native species and encourage non-native species 3. Flow is a major determinant of habitat and transport 4. Recent Delta environmental flows are insufficient to support native Delta fishes for today’s habitats 5. A strong science program and a flexible management regime are essential to improving flow criteria Five Key Points 20

21. + - Nutrients Organic matter Sediment Fish Floodplains Proportion Diverted What Changes As Flow Increases? X2X2 - Delta Residence Time - River Stage, Velocity + Location of Any Salinity Range - Salinity At a Point LSZLSZ 21

22. Delta smelt habitat abundance in relation to X2 22

23. Fish Production Benthic Production Zooplankton Production Microbial Production Phytoplankton Production Nutrient Input Organic Input Inputs Hydrodynamic Forcing : Freshwater inflow Oceanic variability Wind Stratification Transport/ Retention Physical Habitat Physical forcing mechanisms Material flows Direct physical influences Key feedback loop Conceptual Model: Physical effects on estuarine ecosystem 23

24. How much water do fish need? 24