Chlorophyll and phytoplankton community changes in a shifting CO 2 environment

Chlorophyll and phytoplankton community changes in a shifting

CO2 environment

Natsuko Porcino

University of Washington, Friday Harbor Labs

Spring 2013

What are phytoplankton?

Photo courtesy of Amy Stephens

• Microscopic photosynthetic organisms

• The primary producers of the ocean

• Account for half of all photosynthetic activity on Earth

Cyanobacteria (0.5 – 2 microns)

Nanoplankton (2 – 5 microns)

Large phytoplankton (5+ microns)

CHLOROPHYLL

• Used by primary producers to photosynthesize

• A fluorophore

Were chlorophyll a levels different between the treatments?

What populations were present? Were they different between CO2 levels?

Methods

T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T210.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0Median chlorophyll values by day, by treatment

Control

High

Drift

Time (days)

Ch

loro

ph

yll (

ugL

-1)

High and drift: p<0.001 Control and high: p<0.001Control and drift: p=0.728

(Friedman Rank Sum Test)

01/03/1900 01/07/19000

200

400

600

800

1000

1200

1400

1600

1800

0

5

10

15

20

25Chlorophyll and large phytoplankton counts over time

chlorophyll control

chlorophyll high

chlorophyll drift

phytoplankton control

phytoplankton high

phytoplankton drift

Time (days)

Ph

ytop

lan

kto

n (

cell

s m

l-1

)

Ch

loro

ph

yll (

ugL

-1 )

T0 T2 T4 T6 T8 T10 T12 T14 T16 T18 T20

Control: rho=0.95, p<2.2x10-16

High: rho=0.93, p=1.3x10-14

Drift: rho=0.93, p=7.9x10-15

(Spearman Rank Correlation)

Were chlorophyll a levels different between the treatments?

What populations were present? Were they different between CO2 levels?

Flow cytometry

fluorophore

light

fluorophore

emits light

FCM diagram courtesy of MUSC Department of Regenerative Medicine and Cell Biology

FL2-H (phycoerithrin, phycocyanin)

FL3-H(chlorophyll)

FSC-H(size)

SSC-H(complexity)

Cyanobacteria (0.5 – 2 microns)

Nanoplankton (2 – 5 microns)

Large phytoplankton (5+ microns)

Control (bag 1) High (bag 2) Drift (bag 3)

Day 2

Day 14

Day 21

2 6 12 13 14 15 16 17 18 19 20 210

200

400

600

800

1000

1200

1400

1600

1800Different FCM gated communities through time

synCsynHsynDeukC

Time (days)

Cel

l cou

nts

(ce

lls

ml-

1 ) Control and drift: p=0.001

Control and high: p=0.02Drift and high: p=0.35

(Kruskal-Willis Test)

2 6 12 13 14 15 16 17 18 19 20 210

200

400

600

800

1000

1200

1400

1600

1800

Different FCM gated communities through time

synCsynHsynDnanoCnanoHnanoDeukC

Time (days)

Cel

l cou

nts

(ce

lls

ml-

1 ) Control and drift: p=0.003

Control and high: p<0.001Drift and high: p=0.003

(Kruskal-Willis Test)

2 6 12 13 14 15 16 17 18 19 20 210

200

400

600

800

1000

1200

1400

1600

1800

Different FCM gated communities through time

synCsynHsynDnanoCnanoHnanoDeukCeukHeukD

Time (days)

Cel

l cou

nts

(ce

lls

ml-

1 )

Chi-squared: 1.35p=0.51

(Kruskal-Willis Test)

1 2 3 4 5 6 7 8 9 10 11 120%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Control treatment

1 2 3 4 5 6 7 8 9 10 11 120%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

High treatment

1 2 3 4 5 6 7 8 9 10 11 120%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Drift treatment

Blue = small phytoplankton (<2 microns)

Red = nanoplankton (2-5 microns)

Green = large phyoplankton (>5 microns)

T2 T6 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T2 T6 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T2 T6 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21

T2 T6 T12 T14 T16 T18 T200

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

Bacterial, nanoplankton, and larger phytoplankton cell counts over time

FCM controlFCM highFCM driftphytoplank-ton controlbacteria control

Time (days)

Ph

ytop

lan

kto

n a

nd

FC

M c

oun

ts (

cell

s m

l-1

)

Bac

teri

al c

oun

ts (

cell

s m

l-1

)

T2 T6 T12 T14 T16 T18 T200

200

400

600

800

1000

1200

1400

1600

0

500000

1000000

1500000

2000000

2500000

3000000

3500000Bacterial, nanoplankton, and larger phytoplankton cell counts over time

FCM control

FCM high

FCM drift

phytoplankton control

phytoplankton high

phytoplankton drift

bacteria control

Time (days)

Ph

ytop

lan

kto

n a

nd

FC

M c

oun

ts (

cell

s m

l-1

)

Bac

teri

al c

oun

ts (

cell

s m

l-1

)

T2 T6 T12 T14 T16 T18 T200

200

400

600

800

1000

1200

1400

1600

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

Bacterial, nanoplankton, and larger phytoplankton cell counts over time

FCM control

FCM high

FCM drift

phytoplankton control

phytoplankton high

phytoplankton drift

bacteria control

bacteria high

bacteria drift

Time (days)

Ph

ytop

lan

kto

n a

nd

FC

M c

oun

ts (

cell

s m

l-1

)

Bac

teri

al c

oun

ts (

cell

s m

l-1

)

T2 T6 T12 T14 T16 T18 T200

200

400

600

800

1000

1200

1400

1600

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

Bacterial, nanoplankton, and larger phytoplankton cell counts over time

Time (days)

Ph

ytop

lan

kto

n a

nd

FC

M c

oun

ts (

cell

s m

l-1

)

Bac

teri

al c

oun

ts (

cell

s m

l-1

)

T2 T6 T12 T14 T16 T18 T200

200

400

600

800

1000

1200

1400

1600

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

Bacterial, nanoplankton, and larger phytoplankton cell counts over time

Time (days)

Ph

ytop

lan

kto

n a

nd

FC

M c

oun

ts (

cell

s m

l-1

)

Bac

teri

al c

oun

ts (

cell

s m

l-1

)

T2 T6 T12 T14 T16 T18 T200

200

400

600

800

1000

1200

1400

1600

0

500000

1000000

1500000

2000000

2500000

3000000

3500000

Bacterial, nanoplankton, and larger phytoplankton cell counts over time

Time (days)

Ph

ytop

lan

kto

n a

nd

FC

M c

oun

ts (

cell

s m

l-1

)

Bac

teri

al c

oun

ts (

cell

s m

l-1

)

Conclusion

• Distinct phytoplankton size classes present

Conclusion

• Shifts in population through time

• Distinct phytoplankton size classes present

Conclusion

• Increasing number of large phytoplankton as the experiment progresses

• Distinct phytoplankton size classes present

• Shifts in population through time

Acknowledgements

James Murray Kelsey Gaessner

Robin Kodner Mike Foy

Ocean Acidification Research ApprenticesFriday Harbor Labs

Shannon Point Marine CenterUW Department of Biology

Educational Foundation of AmericaNational Science Foundation

0 5 10 15 20 250.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

1400.0

1600.0

Chlorophyll and pCO2 through time

control (chl)

drift (chl)

high (chl)

control (pCO2)

high (pCO2)

drift (pCO2)Time (days)

Ch

loro

ph

yll (

ugL

-1 )

pC

O2

(u

atm

)

0 5 10 15 20 250

5

10

15

20

25

30

35

0

50

100

150

200

250

300

350

400

Chlorophyll and O2 through time

Time (days)

Ch

loro

ph

yll (

ugL

-1)

O2

(u

mol

kg-

1 )