Erwin Van Nieuwenhuyse1, Randy Dahlgren2, Chris Foe3, Jon Burau4, Scott Morford2, Harry Horner1, and Nick Sakata1

Bay-Delta Science Conference Sacramento Convention Center, Sacramento, CA October 28, 2014

Cooperative Agreement R12AC20032

1 Bureau of Reclamation 2 University of California, Davis 3 Central Valley Regional Water Quality Control Board 4 U.S. Geological Survey

Objectives

• Limnological overview • Specific conductance, turbidity, temperature • Nutrients (nitrate, ammonium, N:P) • Phytoplankton • Zooplankton • Future work

Map: Delta Atlas, California Department of Water Resources

Cache Slough Complex

*

Rio Vista

*

*

*

Isolated

Mixing zone

Tidal exchange

Sac R

*

M A M J J A S O D J

Specific Conductance

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

F M A M J AS

0

200

400

600

800

1000

1200

EC S/cm

2012 2013

*

*

*

*

µ

*

* *

*

M M J J A S O D J

Turbidity

log (ntu)

A

0.0

0.5

1.0

1.5

2.0

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

MF A M J A S

*

*

*

*

Water temperature (0.5 m)

*

* *

*

(ft)

July 12, 2012

22 23 24 25 26 27 28

-11

-9

-7

-5

-3

-1

NL 62

NL 66

NL 70

NL 74

Dep

th (

m)

Water temperature (C)

*

* *

* August 2, 2013

July 30, 2014

21 22 23 24 25

-11

-9

-7

-5

-3

-1

NL 62

NL 66

NL 70

NL 74

Dep

th (

m)

Water temperature (C)

22 23 24 25

-11

-9

-7

-5

-3

-1

NL 62

NL 66

NL 70

NL 74

Dep

th (

m)

Water temperature (C)

*

*

*

*

A M J J A S O D J

DIN : SRP Mass Ratio

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

F M A M J A SM

N:PRatio

0

1

2

3

4

5

6

7

8

9

*

*

*

* *

M

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

A M J J A S O D J

Nitrate Concentrations

NO3-N

(mg/L)

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

F M A M J A S

*

*

*

* *

*

A M J J A S O D J

Ammonium Concentrations

NH4-N

(mg/L)

0.00

0.05

0.10

0.15

0.20

0.25

0.30

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

M F M A M J A S

*

*

*

*

*

M

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

A M J J A S O D J

log Chorophyll

Pigments (ppb)

Chlorophyll Pigments

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

F M A M J A

Ph

yto

pla

nk

ton

bio

vo

lum

e (

µm

3 /L

)

Anabaena, Microcystis

Rhodomonas, Chroomonas, Cryptomonas

Chlamydomonas, Coelastrum, Oocystis

Melosira, Stephanodiscus, Cyclotella, Synedra, Cocconeis, Gyrosigma, Nitzschia, Stauroneis, Synedra, Epithemia, Eunotia, Pinnularia, Planothidium

Common phytoplankton genera

July 12, 2012

Low Microcystis

* *

*

*

*

A M J J A S O D

Zooplankton Biomass

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Log Zoop

Biomass

(ug/L)

J F M A M J A S

150 micron net

Zo

op

lan

kto

n d

ry w

t (µ

g/L

)

Ceriodaphnia, Daphnia, Diaphanasoma

Sinocalanus, Pseudodiaptomus, calanoid

Conochiloides, Lecane, Polyarthra, Brachionus

Veligers

Common macro-zooplankton genera

July 12, 2012

150 micron net

Smelt Cam

M A M J J A S O D J

Specific Conductance

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

F M A M J AS

0

200

400

600

800

1000

1200

EC S/cm

M M J J A S O D J

Turbidity

log (ntu)

A

0.0

0.5

1.0

1.5

2.0

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

MF A M J A S A M J J A S O D

Zooplankton Biomass

NL84WSP

NL62

NL66

NL70

NL74NL76

NL56

NL44

NL34

NL16

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

Log Zoop

Biomass

(ug/L)

J F M A M J A S

Q1~350 m3/s

Chl1~3 mg/m3

Q2~42 m3/s

Chl2~30 mg/m3

Chl3~6 mg/m3

C3 = (Q1C1 + Q2C2)/(Q1+Q2)

Up

per

Sac

ram

ento

R

Cac

he

Slo

ug

h

Rio Vista

Food export experiments

Port

ADCP/YSI

ADCP/YSI

ADCP/YSI

ADCP/YSI

Rio Vista

Conclusions

• Limnologically interesting • Longitudinal/seasonal variation • Nitrogen-deficient • Chl ~10 ug/L threshold • High zooplankton abundance • High value for delta smelt studies • Tool for boosting Delta food supply

Questions?

Photos by Mark Gowdy