nianzhi (george) jiao, yao zhang xiamen university china

Picoplankton Community Structure

subarctic (K2) v.s.

subtropical (Aloha similar)

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Nianzhi (George) Jiao, Yao Zhang

Xiamen University

China

Investigation Sites

Fig. 1 Sampling stations Chlorophyll a remote images (Aqua-MODIS) of August 2005 were employed as the backgrounds. NWPG: North Western Pacific; NEP: North Eastern Pacific; MNEP: Marginal sea of North Eastern Pacific.

0.01

0.10

1.00

10.0

60.0

mg

m- 3

0

20

40

60

80

K2

NW PG1

NEP1

ALOHA

NEP2 NEP3

160W 140W 120W 100W160E140E120E 180

NW PG2

Picoplankton discrimination by FCM

Prochlorococcus Synechococcus

Picoeukaryotes Heterotrophic bacteria

AAPB (AAPB (aerobic anoxygenic phototrophic bacteriaaerobic anoxygenic phototrophic bacteria))

TIREM TIREM Jiao et al., 2006,Jiao et al., 2006, Journal of Microbiological Methods

Exposure time (min)

0 3 6 9 12 15 18

Cou

nts

/ M

icro

-fie

ld

20

40

60

80

200

Cyano CountDAPI CountIR Count

Paths of Photosynthesis

Karl, 2002

Sunlight

Phtosynthesis in Phytoplankton

Phtosynthesisin AAPB

C fixation

ATP

Save OC Ocean C cycling

Re-budget ??

respiration consumption

Carbon cycling

TEM-Ultrathin sections

SEM

dc10-s

dg26-y-1(2216)

dc10-s

dc10-s

db6-y-2(0.2)

TEM-Negatively stained cells

AAPB cells

Non-AAPB

AAPB

ciliates Meso-zooplanktonflagellates

ciliates

flagellates

Meso-zooplankton

Cellular contribution to sinking flux in AAPB could also be higher than non-AAPB

Deployment 1 Deployment 2 Cell Abundance (cells/ml)

1e+3 1e+4 1e+5 1e+6

De

pth

(m

)

0

10

20

30

40

50

Euk.Syn.Bact.AAPB

Cell Abundance (cells/ml)

1e+3 1e+4 1e+5 1e+60

10

20

30

40

50

Depth profiles of the abundance (upper)And biomass (lower) of picoplankton at K2.

Cell Abundance (cells/ml)

1e+1 1e+2 1e+3 1e+4 1e+5 1e+6

Dep

th (

m)

0

50

100

150

200

Euk.Syn.Bact.AAPB

Cell Abundance (cells/ml)

1e+1 1e+2 1e+3 1e+4 1e+5 1e+60

50

100

150

200

K2Deployment 1

K2Deployment 2

Fig. 4 Depth profiles of picoplankton at K2 with false connection down to 200m.

The data of 60-200m are adopted from Liu et al. 2002.

Picoplankton Carbon Biomass at K2

0 5 10 15 20 25 30

K2Deployment 1

Biomass (C mg/m3)

051015202530

Dep

th (

m)

0

10

20

30

40

50

0 5 10 15 20 25 30

non-AAPBAAPB

K2Deployment 2

Biomass (C mg/m3)

0510152025300

10

20

30

40

50

Euk. Syn.

0 5 10 15 20 25 30

K2Deployment 1

051015202530

Dep

th (

m)

0

50

100

150

200

0 5 10 15 20 25 30

non-AAPBAAPB

K2Deployment 2

0510152025300

50

100

150

200

Euk. Syn.

Fig. 5 Depth profiles of pico-sized autotrophic and heterotrophic carbon biomass at K2. The data of 60-200m (shaded) were from Liu et al. 2002.

Comparison between K2 and Aloha similars

Fig. 1 Sampling stations Chlorophyll a remote images (Aqua-MODIS) of August 2005 were employed as the backgrounds. NWPG: North Western Pacific; NEP: North Eastern Pacific; MNEP: Marginal sea of North Eastern Pacific.

0.01

0.10

1.00

10.0

60.0

mg

m- 3

0

20

40

60

80

K2

NW PG1

NEP1

ALOHA

NEP2 NEP3

160W 140W 120W 100W160E140E120E 180

NW PG2

Pico- biomass K2 v.s. NWPG

Fig. 6 Vertical distribution of pico-sized autotrophic and heterotrophic carbon biomass

at K2 and NWPG1

0 5 10 15 20 25 30

K2

Biomass (C mg/m3)

051015202530

Dep

th (

m)

0

50

100

150

200

0 5 10 15 20 25 30

non-AAPBAAPB

NWPG1

Biomass (C mg/m3)

0510152025300

50

100

150

200

Pro.Euk.Syn.

Surface layer: Auto > hetero Auto < heteroTwilight zone: Auto < hetero Auto > hetero

GyreK2

Comparison along longitude

Fig. 1 Sampling stations Chlorophyll a remote images (Aqua-MODIS) of August 2005 were employed as the backgrounds. NWPG: North Western Pacific; NEP: North Eastern Pacific; MNEP: Marginal sea of North Eastern Pacific.

0.01

0.10

1.00

10.0

60.0

mg

m- 3

0

20

40

60

80

K2

NW PG1

NEP1

ALOHA

NEP2 NEP3

160W 140W 120W 100W160E140E120E 180

NW PG2

NEP1, 2 ,3,4Auto –fraction

increased eastward

Vertical distibution of pico-sized autotrophic and heterotrophic carbon biomas

s at NEP

0 5 10 15 20 25

NEP3

0510152025

Depth

(m

)

0

50

100

150

200

0 5 10 15 20 25

NEP2

0510152025

Depth

(m

)

0

50

100

150

200

0 5 10 15 20 25

non-AAPBAAPB

NEP1

Biomass (C mg/m3)

0510152025

Depth

(m

)

0

50

100

150

200

Pro.Euk.Syn.

Fig. 10 Variation of vertical profiles of pico-sized autotrophic and heterotrophic carbon biomass along longit

ude

0 10 20 30 40 50 60

non-AAPB AAPB

NEP4Deployment 1

Biomass (C mg/m3)

0102030405060

De

pth

(m

)

0

50

100

150

200

Pro.Euk.Syn.

0 10 20 30 40 50 60

NEP4Deployment 2

Biomass (C mg/m3)

01020304050600

50

100

150

200

0 10 20 30 40 50 60

NEP4Deployment 3

0102030405060

De

pth

(m

)

0

50

100

150

200

0 10 20 30 40 50 60

NEP4Deployment 4

01020304050600

50

100

150

200

0 10 20 30 40 50 60

NEP

01020304050600

50

100

150

200

0 10 20 30 40 50 60

NEP2

0102030405060

De

pth

(m

)

0

50

100

150

200

0 10 20 30 40 50 60

NEP1

01020304050600

50

100

150

200

0 10 20 30 40 50 60

NWPG2

0102030405060

De

pth

(m

)

0

50

100

150

200

0 10 20 30 40 50 60

NWPG1

01020304050600

50

100

150

200

NEP4 (1,2,3,4) <=> K2 (1,2) in terms of Biomass flux and auto/hetero ratio; although composition are different

0 10 20 30 40 50 60

non-AAPB AAPB

MNEPDeployment 1

Biomass (C mg/m3)

0102030405060

Dep

th (

m)

0

50

100

150

200

Pro.Euk.Pro.

0 10 20 30 40 50 60

MNEPDeployment 2

Biomass (C mg/m3)

01020304050600

50

100

150

200

0 10 20 30 40 50 60

MNEPDeployment 3

0102030405060

Dep

th (

m)

0

50

100

150

200

0 10 20 30 40 50 60

MNEPDeployment 4

01020304050600

50

100

150

200

Vertical distribution of pico-sized autotrophic and heterotro

phic carbon biomass at NEP4

Depth profiles ofpico-sized autotrophic and heterotrophic carbon biomass

at K2

Two dimensional trends

0.01

0.10

1.00

10.0

60.0

mg

m- 3

0

20

40

60

80

K2

NEP3

120W 100W160E140E120E

NW PG2Along trophic gradient

Alo

ng

la

titu

de

180 160W 140W

Conclusions• Picoeukaryoes and Synechococcus dominate carbon biomass of

pico-autotrophs at K2 • Prochlorococcus dominate carbon biomass of pico-autotrophs at l

ow latitudes especially in the oligotrophic areas. • AAPB are more abundant in entrophic waters than in oligotrphic w

aters

• picoplankton carbon flux maximum layer depth eutrophic waters: 50-75m oligotrophic waters: 100-150m

• Temperature and nutrients are two major controlling factors

• Variations along gradients: autotrophs >> heterotrophic bacteria • Therefore whether or not a province is autotrophic or heterotrophi

c is determined primarily by autotrophs

Cheers!

K2 Aloha