Constraining Primary Production in a pCO2 Manipulation Mesocosm Experiment

Andrew Charles BairdUniversity of Washington Friday Harbor Laboratories

•Why look at the effects of pCO2?- Ocean Acidification

- Carbonate Chemistry

•The Mesocosm Approach

•Net Community Production

•Redfield Ratio

•Results!

•Why look at the effects of pCO2?- Ocean Acidification

- Carbonate Chemistry

•The Mesocosm Approach-Experimental Design

•Net Community Production

•Redfield Ratio

•Results!

•Why look at the effects of pCO2?- Ocean Acidification

- Carbonate Chemistry

•The Mesocosm Approach-Experimental Design

•Net Community Production-What is it?

-How is it measured?

•Redfield Ratio

•Results!

•Why look at the effects of pCO2?- Ocean Acidification

- Carbonate Chemistry

•The Mesocosm Approach-Experimental Design

•Net Community Production-What is it?

-How is it measured?

•Results!

•Redfield Ratio-Nutrient Relationships

-Stoichiometry

P15

+ CN +67

=

LIFE! + O8

•Why look at the effects of pCO2?- Ocean Acidification

- Carbonate Chemistry

•The Mesocosm Approach-Experimental Design

•Net Community Production-What is it?

-How is it measured?

•Results!-the exciting bit

•Redfield Ratio-Nutrient Relationships

-Stoichiometry

225.0

250.0

275.0

300.0

325.0

350.0

375.0

400.0

µmol

O2

L-1

CO2 + H2O H2CO3 H+ + HCO3- H+ + CO3

2-

•Why look at the effects of pCO2?

•The Mesocosm Approach-Experimental Design

•Net Community Production

•Redfield Ratio

•Results!

650ppm(Constant)

1200ppm(Constant)

1200ppm(Variable)

Control High Drift

x3 x3 x3

The Mesocosm Approach

•Constrain an extremely variable system:

-Replication possible-Manipulate

conditions-Trophic level

interactions

• International Scientific collaboration!

•Why look at the effects of pCO2?

•The Mesocosm Approach

•Net Community Production-What is it?

-How is it measured?

•Redfield Ratio

•Results!

What is Primary Production?

$150

O2

What is Primary Production?

$150

O2

Gross Community Production (GCP)

What is Primary Production?

$150

Gross Community Production (GCP)

$50

What is Primary Production?

$150

Gross Community Production (GCP)

$50

Community Respiration (CR)

$100

What is Primary Production?

$150

Gross Community Production (GCP)

$50

Community Respiration (CR)

$100

Net Community Production (NCP)

How is NCP measured?

• Radioactive tracers: 14C, 18O

• In situ differences in O2/CO2 utilization

• Nutrient Relationships

How is NCP measured?

• Radioactive tracers: 14C, 18O

• In situ differences in O2/CO2 utilization

• Nutrient Relationships

Daily Oxygen Measurements

•Why look at the effects of pCO2?

•The Mesocosm Approach

•Net Community Production

•Results!

•Redfield Ratio-Nutrient Relationships

-Stoichiometry

P15

+ CN +67

=

LIFE! + O8

The Redfield RatioP N C O2

1 16 106 138

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

*From Redfield, Ketchum & Richards 1934

*

*

1 16 106 138

106 16 P138

Generalized Organic Matter

The Redfield RatioP N C O2

1 16 106 138

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

Generalized Organic Matter

*From Redfield, Ketchum & Richards 1934

*

*

Production Respiration

The Redfield RatioP N C O2

1 16 106 138

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

Generalized Organic Matter

*From Redfield, Ketchum & Richards 1934

*

*

The Redfield RatioP N C O2

1 16 106 138

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

Generalized Organic Matter

*From Redfield, Ketchum & Richards 1934

*

*

10 µmol NO3-

L = µmol O2

L

µmol O2

The Redfield RatioP N C O2

1 16 106 138

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

Generalized Organic Matter

*From Redfield, Ketchum & Richards 1934

*

*

10 µmol NO3-

L x 138 µmol O2

L16 µmol N= 86

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21225.0

250.0

275.0

300.0

325.0

350.0

375.0

400.0

Control

High

Drift

DS

time

µmol

O2

L-1

Oxygen Concentration [µmol L-1] – Medians

Statistical difference is significant only between Control and High (p=0.004, F2,21 =-0.508)

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21225.0

250.0

275.0

300.0

325.0

350.0

375.0

400.0

Control

High

Drift

DS

time

µmol

O2

L-1

Statistical difference is significant only between Control and High (p=0.004, F2,21 =-0.508)

Phase 1 Phase 2

Oxygen Concentration [µmol L-1] – Medians

M1 M2 M3 M4 M5 M6 M7 M8 M9

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

Phase 1Phase 2

µmol

O2

L-1

d-1

•High significant difference found between Phase1 and Phase2 (t=-6.472, p<0.001)•No significant difference found between treatment groups in Phase1 or Phase2 (p>0.05)

Observed Net Community Production Between Phase 1 & Phase 2

Phase 1

• Net heterotrophy

Phase 2

• Net autotrophy

Phase 1

• Net heterotrophy– Grazers/Respirators dominating

community– Should see decrease in [O2]

Phase 2

• Net autotrophy– Phytoplankton/Producers most

prevalent in food web– Distinct increase in [O2]

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21225.0

250.0

275.0

300.0

325.0

350.0

375.0

400.0

ControlHighDriftDS

µmol

O2

L-1

Phase 1

• Net heterotrophy– Grazers/Respirators dominating

community– Should see decrease in [O2]

Phase 2

• Net autotrophy– Phytoplankton/Producers most

prevalent in food web– Distinct increase in [O2]

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T1210

15

20

25

30

35

M1M2M3M4M5M6M7M8M9Dock

time

µmol

NO

3 L-

1

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

NO3 Trend - Phase 1

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T1210

15

20

25

30

35

M1M2M3M4M5M6M7M8M9Dock

time

µmol

NO

3 L-

1

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

(CH2O)106 (NH3)16 (H3PO4) + 138O2

NO3 Trend - Phase 1

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T1210

15

20

25

30

35

f(x) = − 0.475274725274725 x + 25.6192307692308R² = 0.921173478181648

M1M2M3M4M5M6M7M8M9Linear (M9)Dock

time

µmol

NO

3 L-

1NO3 Trend - Phase 1

M9

µmol O20.48 µmol NO3-

L day x 138 µmol O2

16 µmol N= 4.14

L dayM9

Uptake Rate – Phase 1

µmol O20.48 µmol NO3-

L day x 138 µmol O2

16 µmol N= 4.14

L dayM9

Uptake Rate – Phase 1

M1 M2 M3 M4 M5 M6 M7 M8 M90

1

2

3

4

5

6PHASE 1

Calculated d[O2]*

µmol

O2

L-1

d-1

M1 M2 M3 M4 M5 M6 M7 M8 M902468

10121416182022

PHASE 2

Calculated d[O2]*

µmol

O2

L-1

d-1

M1 M2 M3 M4 M5 M6 M7 M8 M90

1

2

3

4

5

6PHASE 1

Calculated d[O2]*

µmol

O2

L-1

d-1

High significance found between Phase 1 & Phase 2 “calculated d[O2]” (p<0.001)

M1 M2 M3 M4 M5 M6 M7 M8 M902468

10121416182022

PHASE 2Measured d[O2]Calculated d[O2]*

µmol

O2

L-1

d-1

M1 M2 M3 M4 M5 M6 M7 M8 M9-1

0

1

2

3

4

5

6PHASE 1

Measured d[O2]

Calculated d[O2]*

µmol

O2

L-1

d-1

High significance found between Phase 1 & Phase 2 “calculated d[O2]” (p<0.001)

Net Community Production Gross Community Production

M1 M2 M3 M4 M5 M6 M7 M8 M9 ave0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Phase 1Phase 2

µmol

O2

L-1

d-1

Community Respiration Between Phase 1 & Phase 2

Statistical significance found between Phase 1 and Phase 2. (t= -4.671, p=0.002)

How did our microplankton communities effect nutrient interaction?

Control High Drift Redfield

Nitrate (NO3-) vs Oxygen (O2) – Phase 2

138 µmol O2

-16 µmol N =-8.6 µmol O2

µmol N

0 5 10 15 20 25 30 350

50

100

150

200

250

300

350

400

450

Control

High

Drift

Dock

µmol NO3 L-1

µmol

O2

L-1

y= -8.63x

Control High Drift Redfield

-8.6

0 5 10 15 20 25 30 350

50

100

150

200

250

300

350

400

450

Control

High

Drift

Dock

µmol NO3 L-1

µmol

O2

L-1

Nitrate (NO3-) vs Oxygen (O2) – Phase 2

y= -8.63x

Control High Drift Redfield

-6.1 -8.6

0 5 10 15 20 25 30 350

50

100

150

200

250

300

350

400

450

R² = 0.966235159771381

Control

Linear (Control)

High

Drift

Dock

µmol NO3 L-1

µmol

O2

L-1

Nitrate (NO3-) vs Oxygen (O2) – Phase 2

0 5 10 15 20 25 30 350

50

100

150

200

250

300

350

400

450

R² = 0.945174033646846

R² = 0.966235159771381

ControlLinear (Control)HighLinear (High)DriftDock

µmol NO3 L-1

µmol

O2

L-1

Control High Drift Redfield

-6.1 -5.1 -8.6

y= -8.63x

Nitrate (NO3-) vs Oxygen (O2) – Phase 2

0 5 10 15 20 25 30 350

50

100

150

200

250

300

350

400

450

R² = 0.947986315973768R² = 0.945174033646846

R² = 0.966235159771381

ControlLinear (Control)HighLinear (High)DriftLinear (Drift)Dock

µmol NO3 L-1

µmol

O2

L-1

Control High Drift Redfield

-6.1 -5.1 -5.7 -8.6

y= -8.63x

Nitrate (NO3-) vs Oxygen (O2) – Phase 2

•High Significant Correlation between NO3 & O2 (p<0.001)

Conclusion!

•Ocean Acidification-Growing Issue

•NCP, GCP, CR

•Phase 1 vs Phase 2

•Mesocosm vs Redfield

O2

106CO2 + 16H+ + 16NO3- + H3PO4 + 122H2O

Conclusion!

(CH2O)106 (NH3)16 (H3PO4) + 138O2

•Ocean Acidification-Growing Issue

•NCP, GCP, CR -Nutrient Balance and Redfield

•Phase 1 vs Phase 2

•Mesocosm vs Redfield

M1 M2 M3 M4 M5 M6 M7 M8 M9-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

Phase 1

Phase 2

µmol

O2

L-1

d-1

Production Rates

Conclusion!

mesocosm

•Ocean Acidification-Growing Issue

•NCP, GCP, CR -Nutrient Balance and Redfield

•Phase 1 vs Phase 2-light limitation more of an effect than CO2?

•Mesocosm vs Redfield

•Ocean Acidification-Growing Issue

•NCP, GCP, CR -Nutrient Balance and Redfield

•Phase 1 vs Phase 2-light limitation more of an effect than CO2?

•Mesocosm vs Redfield-Decreased O2:N-Oxygen stoichiometry? -Increased Carbon Demand?

Conclusion!

Thank You!- Jim Murray

- Evelyn Lessard

- Jorun Egge

- Mike Foy

- Barbara Paul

- Amanda Fay

- Molly Roberts

- Kelsey Gaessner

- My Mom

- Philslips Gravinese

- Kiely Shutt

- Kelly Govenar

- Jen Apple

- Kitae Park

- Amy Stevens

- Natsuko Porcino

- Daneil Newcomb

- Herbs Tavern

Questions?