Digital Map fromDr. William Bowen California State University Northridge

Sacramento-San Joaquin

DeltaSan Joaquin

River

Sacramento River

Suisun Bay

San Francisco

1

2

Stationary Habitat ---Geometry

Dynamic Habitat ---Hydrodynamics, ocean conditions, weather

Environment

Biological Conditions

3

Estuarine habitat conceptual model(Peterson 2003)

Stationary Habitat

Dynamic Habitat

Production AreaTidal and River Flow

PelagicRecruitment

4

Hydrology

Delta Geometry

Water Demand

Exports

Delta Hydrodynamics

Realized Habitat

Potential Habitat

Biological and Chemical Conditions

5

Tides

0 50 100 150 200 250 300 3500

0

5

10

15

O N D J F M A M J J A S

Day of Water Year

W D

1983 1977 1998 1991 1995 1992 1982 1990 1958 1994 (1997)

Dry Years

Wet Years

Fres

hwat

er F

low

(m3 s

-1)

Variability of Freshwater Delta Inflow

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7

Pelagic organisms follow salinity:The copepod Eurytemora affinis

Kimmerer 1998

40 50 60 70 80 90 10040

50

60

70

80

90

100

110 1:1 Regression Line

X2 (km)

Pos

ition

of P

eak

(km

)

8X2 (km)

1009080706050

100

90

80

70

60

50

X2

Cente

r of dis

trib

ution

1:1

Pelagic organisms follow salinity: Delta smelt

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0 10 20 300

20

40

60

80

100Delta smelt

Shiner

perch

Thr. shadAm. shad

Striped bass

Chinook salmon

YF goby

Starry flounder

Longfin smelt

Salinity

C

umul

ativ

e P

erce

nt

Staghorn sculpin

Splittail

Most fishes follow salinities

Kimmerer 2004

Marine species

10

1967-871988-2000

1982-2000 (DS)All Years

1

2

3

4

1

2

3

4

0

1

2

3

2

3

4

5

0

1

2

3

2

3

4

5

50 60 70 80 90

0

1

2

3

50 60 70 80 90

-2

-1

0

1

Bay Shrimp

Striped BassSplittail

Longfin smeltDelta smelt

Herring Am. Shad

Flounder

Log

Abu

ndan

ce o

r S

urvi

val

X2 (km)High Flow Low FlowSource:

Kimmerer 2002MEPS

Higher trophic levels show many

relationships of abundance to

freshwater flow

11X2 (km)

0

1

2

0

1

2

1

2

3

4

1

2

3

4

50 60 70 80 90

2

3

4

5

50 60 70 80 90-2-1012

Mysid

Copepod: Spring

Copepod: Summer

Rotifer: Summer

Chlorophyll: SummerChlorophyll: Spring

Log

Abu

ndan

ce

X2(km)

High Flow Low Flow

Lower trophic levels show few relationships

of abundance to freshwater flow

Source:Kimmerer 2002 MEPS

1972-19871988-2000

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X2 (km)

1873 Delta:

Long residence time

Marsh connections

Two rivers connect to bay

Waterways dendritic

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Modern delta

Short residence times

Rip-rapped

Cross Delta flows

Rare San Joaquin connection to bay

Waterways web-like14

What Changes As Flow Increases?

X2Location of Any Salinity

RangeLSZ

Salinity and X2

FLOW

15

stratification

Proportion

Diverted

What Changes As Flow Increases?

Delta

Residence Time

RiverStage,Velocity

River

stage and

velocity

Floodplain

inundation

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FLOW

FLOW

Upstream

bottom current

Nutrients

Contaminants

Organic matter

Sediment

What Changes As Flow Increases?

Concentrations

Loadings

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FLOW

FLOW

What Changes As Flow Increases?

Adult spawners move up:SalmonGreen and White

SturgeonLongfin smeltDelta smeltSplittailAmerican shadPacific herring

Young Marine fish move up:Starry flounderWhite croakerPacific halibut

Young fish move down:SalmonLongfin smeltDelta smeltSplittailAmerican shadStriped bass

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Flows are important but so is geometry

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 transport4. Recent Delta environmental flows are insufficient to support

native Delta fishes for today’s habitats5. A strong science program and a flexible management

regime are essential to improving flow criteria

Five Key Points

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+

-

Nutrients

Organic matter

Sediment

Fish

Proportion

Diverted

What Changes As Flow Increases?

X2

-Delta

Residence Time

-River

Stage,Velocity

+

Location of Any Salinity

Range

-Salinity

At a

Point

LSZ

21

Delta smelt habitat abundance in relation to X2

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Fish

Production

Benthic

Production

Zooplankton

Production

Microbial

Production

Phytoplankton

Production

Nutrient

Input

Organic

InputInputs

Hydrodynamic Forcing:

Freshwater inflowOceanic 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

How much water do fish need?

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