Co-Limitation of Phytoplankton by Light and Multiple Nutrients Hein de Baar, Klaas Timmermans, Loes...

Co-Limitation of Phytoplanktonby Light and Multiple Nutrients

Hein de Baar, Klaas Timmermans, Loes Gerringa, Erik Buitenhuis, Patrick Laan;

Christiane Lancelot, Olivier Aumont, Geraldine Sarthou, Andy Bowie, Stephane Blain, Paul Worsfold

and many others in European research teams of MERLIM, CARUSO, IRONAGES

Koninklijk Nederlands Instituut voor Onderzoek der ZeeRoyal Netherlands Institute for Sea Research

Europese UnieEuropean Union

Contents

• Building Blocks for Life• Concepts of Limitation• Observations in the Sea• Growth Experiments• Ironages• GEOTRACES (GEOSECS II)• Summary

Abundance of Chemical Elements

HeO

Mg

O

-3

-2

-1

0

1

2

3

4

5

6

7

8

9

10

11

0 10 20 30 40 50 60 70 80 90 100

Ar

Ti

Cr

UTh

H

He

Li

Be

B

C

N

F

NeSi

S

Ca

Fe

Ni

ZnMn

CoCu

Ag

CdHg

Pb

Mg

NaAl

PCl

10 L

og(A

bund

ance

)

Atomic Number

O

Major Bio-ElementsAbundances versus one million Si atoms

• Carbon• Nitrogen• Silicon• Phosphor

us• Iron

• 10 x 106

• 3 x 106

• 1 x 106

• 1 x 104

• 0.9 x 106

Metals Abundance & Biological Evolution

Evolution used abundant metals: essentialLow abundant metals no bio-functions: toxic

Pb315

Hg0.34

Cd ?1.61

Ag0.49

Zn1260

Cu522

Ni49300

Co2250

Fe900000

Mn9550

numbers of atoms versus 1 million Si atoms

Photosynthetic Oxygen Captured in Iron Formations

0

1

2

3

4

5

6

7

3.8 3.3 2.8 2.3 1.8 1.3 0.8 0.3

Time before present [Gyrs = 109 years]

1017

kg

Fe2O3 formed

4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0

4 Fe(II)dissolved + 3 O2 2 (Fe2O3)deposit

oxygen in the air

photosynthesisDumb algaetook away

theirown iron supply

2. Concepts of limitation [nutrient]------- = ----------------------------max ( Knutrient + [nutrient] )

Michaelis, M. & Menten, M.L. (1913) Kinetics of invertase action. Zeitschrift f. Biochemie, 49, 333.Monod, J. (1942) Recherches sur la croissance des cultures bacteriennes. Paris, Herrmann. Emiliania huxleyi

in pristine natural seawater

driven into iron limitation by siderophore addition

Timmermans et al., in prep.

Multiple Limitations in Real Ocean

• Caveats– static (steady state) equation applied to

dynamic wax and wane of plankton blooms– limitations presumed independent while within

living cell they are all interacting

de Baar and Boyd (2000) JGOFS Midterm Synthesis Book

[N] [P] [Fe] [Si]----- = {(1-exp(aI/Kmax)}{-----------}{----------}{------------}{-----------} max (KN+ [N]) (KP+[P]) (KFe+[Fe]) (KSi+[Si])

growth light nitrate phosphate iron silicategrowth light nitrate phosphate iron silicate

Moreover terms for Mn, Cu, Zn, Co to be included as well !?

Some examples of interactions

within the plant cell

• Iron-light co-limitation– electron transfer in photosystems

• Iron essential for nitrate uptake– nitrate reductase, nitrite

reductase

• Zinc - bicarbonate co-limitation– carbonic anhydrase

3. Observations in the Sea

• Zn and silicate• Cd and phosphate• Cu and Ag and silicate• Fractionations Zn/Cd and Cu/Ag• Anomalies of major nutrients

Zinc resembles SilicateD

epth

[m

] Zn [nM]

North PacificOcean(33°N, 145°W)

Bruland (1980)-5000

-4500

-4000

-3500

-3000

-2500

-2000

-1500

-1000

-500

00 2 4 6 8 10

Zn [nM]

0.053 Si [uM]

Cadmium resembles PhosphateCd [nM]

Dep

th [

m]


Bruland (1980)-5000

-4500

-4000

-3500

-3000

-2500

-2000

-1500

-1000

-500

00 0.2 0.4 0.6 0.8 1 1.2

Cd [nM]0.331 PO4

Improved accuracy of both Cd and PO4 is crucial for further progress

Loscher, vander Meer, de Baar, Saager, de Jong (1998) The global Cd/phosphate relationship in deep ocean waters and the need for accuracy. Mar Chem., 59, 87-93

Global Cd/phosphate dataset for waters >1000m depth.

Open circles deBaar et al. (1994);

Filled circles new data Loscher etal (1998).

Biological function for Cd after all

• Replacement of Zn by Cd in marine phytoplankton. Lee and Morel, Mar.Ecol.Prog.Ser., 127, 305-309, 1995

• A biological function for Cd in marine diatoms. Lane and Morel, Proc. Nat.Acad.Sci., 97, 4627-463, 2000

Pb315

Hg0.34

Cd ?1.61

Ag0.49

Zn1260

Cu522

Ni49300

Co2250

Fe900000

Mn9550

carbonicanhydrase

join theGreenParty

Silver (Ag) resembles Copper (Cu)


Martin et al. (1983)-1000

-900

-800

-700

-600

-500

-400

-300

-200

-100

00 1 2 3 4 5 6 7 8 9 10 11 12

Ag [pM] or tenfold Cu [nM]

Dep

th [

m]

10 x Cu [nM]Ag [pM]

Ag has better correlation with Si

Zhang, Amakawa & Nozaki (2001) Mar. Chem., 75, 151

Worldwide correlation Ag and Si

Zhang, Amakawa & Nozaki (2001) Mar. Chem., 75, 151

Ag/Si ratio increases from~1.2 10-6 in Atlanticto~2.7 10-6 in Pacific

Fractionations Cu/Ag and Zn/Cd

Periodic Table Group 1b Group 2b

Cu /Ag Zn / Cd

Crustal abundance ratio ~1060~780

Oceanic waters ratio ~8 + 3~91

Fractionation factor ~130~8.6

Pb315

Hg0.34

Cd ?1.61

Ag0.49

Zn1260

Cu522

Ni49300

Co2250

Fe900000

Mn9550

First row ‘real biometals’ have shorter ocean residence time than second row ‘abiotic’ metals

(Also differences inorganic speciation)

Nutrient anomalies Fragilariopsis kerguelensis blooms

Deep Sea Research II, 44, 229-260 (1997)

anomalous slope

Fragilariopsis kerguelensis with heavily silicified armor ‘pantzer’

More Fe co-limitations major nutrients

Study Fe-deplete Fe-repleteSouthern Ocean (Takeda, 1998) plankton community Si/N=2.3 Si/N = 0.95

N/P = 12 N/P = 14Chaetoceros dichaeta Si/N = 1.9 Si/N = 0.7Nitzschia sp. Si/N = 2.1 Si/N = 1.2

California upwelling (Hutchins et al., 1998)plankton community Si/N = 1.6 Si/N = 0.8

Si/N = 2.7 Si/N = 1.0Si/N = 3.0 Si/N = 1.0

Uptake by blooms in Ross Sea DiatomsPhaeocystisArrigo et al. (1999) N/P = 9.5 N/P = ~19

Three more recent cases of nitrate anomalies in Fragilariopsis blooms

Polarstern1999

Polarstern2000

SOIREE1999

Polarstern2000Polarstern1999

SOIREE1999

February 1999 SOIREE Nutrient Anomalies:

Fragilariopsis kerguelensis strikes again

Nutrients data courtesy Stuart Pickmere, NIWA, New Zealand

end of bloom season

Polarstern 1999 survey cruise:NOx/PO4 anomalies at stations

dominated by Fragilariopsis

Polarstern (2000) in situ Fe enrichment

y = 0.4756x + 16.394

R2 = 0.8868

y = 0.181x + 20.98

R2 = 0.7442

15.00

17.00

19.00

21.00

23.00

25.00

27.00

29.00

10.00 12.00 14.00 16.00

Si (uM)

NO3 (uM)

NO3/Si insideNO3/Si-outside

y = 0.0298x + 1.192

R2 = 0.6564

y = 0.0012x + 1.6159

1.00

1.20

1.40

1.60

1.80

2.00

10.00 12.00 14.00 16.00

Si (uM)

PO4 (uM)

PO4/Si-insidePO4/S-outside

y = 2.9355x + 2085.6

R2 = 0.7627

y = 0.5991x + 2122.4

R2 = 0.3882

2100

2110

2120

2130

2140

2150

10.0012.0014.0016.00

Si (uM)

DIC (umol/kg)

DIC/Si-insideDIC/Si-outside

Bozec, Bakker, de Baar, Thomas, Bellerby and Watson (2003) submitted

y = 0.4756x + 16.394

R2 = 0.8868

y = 0.181x + 20.98

R2 = 0.7442

15.00

17.00

19.00

21.00

23.00

25.00

27.00

29.00

10.00 12.00 14.00 16.00

Si (uM)

NO3 (uM)


y = 0.0298x + 1.192

R2 = 0.6564

y = 0.0012x + 1.6159

1.00

1.20

1.40

1.60

1.80

2.00

10.00 12.00 14.00 16.00

Si (uM)

PO4 (uM)


y = 2.9355x + 2085.6

R2 = 0.7627

y = 0.5991x + 2122.4

R2 = 0.3882

2100

2110

2120

2130

2140

2150

10.0012.0014.0016.00

Si (uM)

DIC (umol/kg)


y = 0.4756x + 16.394

R2 = 0.8868

y = 0.181x + 20.98

R2 = 0.7442

15.00

17.00

19.00

21.00

23.00

25.00

27.00

29.00

10.00 12.00 14.00 16.00

Si (uM)

NO3 (uM)


y = 0.0298x + 1.192

R2 = 0.6564

y = 0.0012x + 1.6159

1.00

1.20

1.40

1.60

1.80

2.00

10.00 12.00 14.00 16.00

Si (uM)

PO4 (uM)


y = 2.9355x + 2085.6

R2 = 0.7627

y = 0.5991x + 2122.4

R2 = 0.3882

2100

2110

2120

2130

2140

2150

10.0012.0014.0016.00

Si (uM)

DIC (umol/kg)


Polarstern (2000) in situ Fe enrichment

Polarstern Ironex II RedfieldTakeda(2000) (1994) (1934) (1998)

-Fe +FeC/P 82 90 + 5 106C/N 5.9 6.2 + 0.2 6.6N/P 12 14.3 + 0.2 16 12 14C/Si 2.9 5.1 + 0.3Si/N 2.1 2.3 0.9

in the patch in the patch in bottlesplankton planktonplanktoncommunity community community

(Steinberg &Millero, 1998)

Bozec, Bakker, de Baar, Thomas, Bellerby and Watson (2003) submitted

4. Growth Experiments

• Pristine natural seawater medium• Fragilariopsis kerguelensis• Diatoms are Forever

– light & Fe co-limitation– small versus large Chaetoceros sp.

• Zn-HCO3 co-limitation Emiliania huxleyi

Different forms of Fe in seawater

AlgalCell

[Fe ] [Fe ]

[Fe(III)L]organic complexes

? ?

? ?photoreduction

sidero-phores

solidsFe2O3

Fe(OH)3FeOOHcolloids

photoreduction

[Fe(OH) ][Fe(OH) ]2+

+23+2+

[FeCO ]03

[FeOH ]+

[Fe(II)L]?

Gerringa, de Baar and Timmermans (2000), Marine Chemistry, 68, 335-346

EDTA dopewould disturball this

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 2 4 6 8 10

Fragilariopsis kerguelensis

µ (

d-1

)

Fe dissolved (x10 -9 M )

Km Fediss: 0.44 x 10-9 Mµmax: 0.31 . d-1

Timmermans, van der Wagt, de Baar, in prep.

80 µm

Fragilariopsis kerguelensisin natural Antarctic seawater

Nutrients Stoichiometryof Fragilariopsis kerguelensis

Ratio Southern Ocean IncubationsFe-deplete Fe-deplete Fe-replete

Si : N 7.7 2.5

N : P ~ 5 + 1 ~ 5 + 1 ~12 + 2

heavily silicified Frag.kerguelensis has higher Si/N ratio

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 2 4 6 8 10 12

Actinocyclus sp.

µ (

d-1)

Fe dissolved (x 10 -9 M)

Km Fediss: 0.98 x 10-9 Mµmax: 0.34 . d-1

Klaas Timmermans et al., in prep.

Actinocyclus sp.

Elemental composition in relation to Fediss

mol per liter cell volume

Actinocyclus sp.

Fediss Si N P Si : N N:P (x10-9 M)0.25 18.25 0.69 1.48 27 0.470.45 17.25 0.75 1.50 23 0.500.65 9.88 0.56 1.38 18 0.411.05 5.69 0.59 0.78 10 0.761.85 4.02 0.52 0.52 8 1.003.45 3.66 0.53 0.63 7 0.8510.45 2.36 0.61 0.33 4 1.86

Klaas Timmermans et al., in prep.

Timmermans et al. (2001), MEPS 287 - 297.

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.55

0 10 20 30 40 50

60 µmol photons.m-2.s-1

15µmol photons.m-2.s-1and

Fe’ (x 10-12 M)

µ (

d-1)

open symbols60 mol fotons m-2 sec-1

filled symbols15 mol fotons m-2 sec-1

Light and Fe co-limitation

single cells 4 - 6 µm diameter (small)

Chaetoceros brevis

0

0.1

0.2

0.3

0.4

0.5

0.6

0 2 4 6 8 10

µ (

d-1)

Fe dissolved (x 10 -9 M)

20 h light: 4 h dark

12 h light : 12 h dark

Chaetoceros dichaetaC. dichaetaKmFediss:1.12 x 10-9 M

Timmermans et al. (2001), MEPS 287 - 297.

does notgrow at all

Chain-forminglarge cells

C. dichaeta

C. brevis

single cells 4 - 6 µm diameter (small)

chain-forming cells, individual cells 80 µm long, 30 µm width (large)

Timmermans et al. Limnol & Oceanogr. 46: 699 - 703.

Open Southern Ocean HNLC species

Large versus smallat optimal light levels

0

0.1

0.2

0.3

0.4

0.5

0.6

0 2 4 6 8 10

µ (

d-1)

Fe dissolved ( x 10 -9 M)

C. brevis in its pristine Antarctic seawater“a wonderful start”

growth rates not affected by Fe additions


-0.1

0

0.1

0.2

0.3

0.4

0.5

2 4 6 8 10 12 14

µ (

d-1)

DFOB (M) addition

x 10-9

C. brevis, it works…. a limitation response


effect of Fe: restoration of µ

increasing DFOB

decreasing Fe’

Add DFOB siderophore to tie down the iron

-0.1

0

0.1

0.2

0.3

0.4

0.5

2 4 6 8 10 12 14

µ (

d-1)

DFOB (M) addition

x 10-9

C. brevis, it works…. a limitation response


effect of Fe: restoration of µ

increasing DFOB

decreasing Fe’

10-14

10-13

10-12

10-11

10-10

10-9

10-8

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6 C. brevis

Fe dissolved (M )10

-1410

-1310

-1210

-1110

-1010

-910

-8-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6 C.dichaeta

In the Southern Ocean:Large C. dichaeta is mostly Fe-limited except after Fe supply

Small C. brevis is never Fe-limited but grazer-controlled

ambient dissolved Fe

Km C.brevis0.59 x 10-12 M

Km C.dichaeta:1.12 x 10-9 M


Paradigm Shift

• Old Paradigm (Sunda, Swift, Huntsman, 1991)

– coastal diatom require more Fe than oceanic diatom

• New Paradigm– O.K. but third class of large oceanic

diatoms having high Fe requirement– these large guys are driving export

Emiliania huxleyi

excretes external CaCO3 platelets

Concerted photosynthesis & calcification

Buitenhuis, Timmermans and de Baar, Limnol.Oceanogr., in press

• Zn-carbonic anhydrase permits fast use of [HCO3-]

• Calcification provides the necessary proton to make CO2

Growth on [HCO3-] at 3 different [Zn2+]


Growth on [Zn2+] at constant [HCO3

-]


Suitable Equation for co-limitation ?

• A) Multiply two Monod equations– two nutrients act independently on growth rate

• B) Minimum nutrient governs growth rate– compare [N] with KN to select one of two Monod

– most suitable for independent nutrients

• C) Affinity for [HCO3-] depends on [Zn2+]

– most suitable concept for Zn-carbonic anhydrase


Which would provide the best fit ??

Multiply two Monod equations

filled circles are data; open circles are intersect with 3-D model plane

best fit: mean residual on = 0.018 day-1

Minimum nutrient governs growth rate



Affinity for [HCO3-] depends on [Zn2+]



Best concept but fitnot any better

5. Iron Resources and Oceanic Nutrients;Advancement of Global Environment Simulations• Existing ecosystem model Southern Ocean

– two plankton groups diatoms and nanoplankton– limitation by light and four nutrients N, P, Fe, Si– successful for Polar Front and for SOIREE– (Lancelot et al 2000; Hannon et al 2001)

• Advance to generic global model– five bloom-forming groups: diatoms, calcifiers,

Phaeocystis, N2-fixers, pico-nano-plankton– limitation by light and four nutrients N, P, Fe, Si– embedding in Ocean Biogeochemical Climate

Models

Control of the carbon cycling in the upper ocean

intermediate and deep waters

N, P, SiFe

light pCO2 air

ice heat

Air/seaCO2 flux

upwelling

C Production

Mineralisation

export

Planktonic system

HighTrophicLevels

TCO2

wind atm

z=0

UML

zUMLPOC

C:N:P:Si:FePIC

Christiane Lancelot, Nice 2003 lecture

WML

STR

EUPHOTIC

Uwind

ice

Tair

GSR

Ice-ocean CLIO-model

Alk Sal

pCO2air

nutrient uptakecalcification / dissolution

SWAMCO-4[Sea WAter Microbial

COmmunity]

CO2

- carbonate system- air-sea CO2 flux)

PAR0

PAR

Chl.a Twater

1D-CLIO

Structure of the coupled biological-chemical-physical 1D model


1D SWAMCO-4 results at KERFIX [1993] :

Jul93 Oct93 Jan94 Apr94 Jul942

2.5

3

3.5

4

4.5

5

SST

(°C

)


300

350

400

µat

m

Jul93 Oct93 Jan94 Apr94 Jul94-25

-20

-15

-10

-5

0

5

10

mm

ol m

-2 d

-1

-0.18


10

20

30

40

50

mm

olC

m-2

d-1

2.32

1.33


1

2

3

4

5

6

7

mm

olC

m-3


0.5

1

1.5

µg

l-1


0.2

0.4

0.6

DF

e µ

mol

m-3

Temperature fCO2 air-sea CO2 flux

DFe Chl.aDIA

NAN

PP

Export

moles C m-2 a-1

Prim. Prod/export Taxon succes. Iron/Chl a

moderate diatom bloom and low CO2 sink


1D SWAMCO-4 results at KERFIX [1993] :Thermodynamic & biological control of air-sea CO2 fluxes


2.5

3

3.5

4

4.5

5

SST

(°C

)


300

350

400

µat

m


-20

-15

-10

-5

0

5

10

mm

ol m

-2 d

-1

-0.18

0.90


10

20

30

40

50

mm

olC

m-2

d-1

2.32

1.33


1

2

3

4

5

6

7

mm

olC

m-3


0.5

1

1.5

µg

l-1


0.2

0.4

0.6

DF

e µ

mol

m-3

Temperature fCO2

Prim. Prod/export

no biologyno biology

air-sea CO2 flux

Taxon succes. Iron/Chl a

PP

ExportNAN

DIADFe Chl.a

moles m-2 a-1


1D SWAMCO-4 results at AESOPS [1996]:Thermodynamic & biological control of air-sea CO2 fluxes


-1.5

-1

-0.5

0

0.5

1

SST

(°C

)


300

350

400

µat

mJul96 Oct96 Jan97 Apr97 Jul97

-25

-20

-15

-10

-5

0

5

10

mm

ol m

-2 d

-1

-0.93

0.16


50

100

150

200

mm

olC

m-2

d-1

7.90

1.83


10

20

30

40

50

60

70

mm

olC

m-3


5

10

µg

l-1


2

4

µm

ol m

-3

Temperature fCO2 air-sea CO2 flux

Prim. Prod/export Taxon succes. Iron/Chl a

moles C m-2 a-1

PP

Export

PHAEO DFe

Chl.a


PISCES Model by Olivier Aumont:Co-limiting of 4 taxa by 3 nutrients

Fe

N Si

Example: the Diatoms

6. GEOTRACES (GEOSECS II)

Epoxy-coated stainless steel prototype frame;final type of titanium or carbon fibre, within own clean van

GoFlo withrotatingball valves

NOEXexpanding

silicone closures

driver unitpneumatics

Air tubeslink

Routine deep profiling with ultraclean CTD frame and cable:

allows GEOSECS II for trace elementsDFe (nM)

-4500

-4000

-3500

-3000

-2500

-2000

-1500

-1000

-500

0

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

De

pth

(m

)

34.2

34.1

34.3

NOEX

Geraldine Sarthou, Stephane Blain, Patrick Laan, Klaas Timmermans

October 2003 cruise IRONAGES-3 off West Africa

GOFlo on CTD-frame

GOFlo on single wire

True and accuratedissolved Fe values still are puzzling.

Certified standard is urgently needed

- outliers not shown- IOC station

de Baar and de Jong(2001) Chapter in:Biogeochemistry of Iron

in Seawater

Atlantic Fe distribution in Hamburg model

Modelers are ready to go, but lack of good Fe data for validation

Six and Maier-Reimer, European Ironages project modeling

Dust storm on 25Dust storm on 25thth Sept 2000 off Western Sept 2000 off WesternAfrica observed by SeaWiFS satelliteAfrica observed by SeaWiFS satellite

IRONAGES-1 Cruise, IRONAGES-1 Cruise, Sep 29Sep 29thth–Oct 23–Oct 23rdrd 2000 2000

IRONAGES standard: collection

-10o

-20o

-30o

-40o

50o

40o

30o

20o

10o

0o

0o-20o 20o-40o-60o

Start

Finish

AtlanticAtlanticOceanOcean

<0.25 0.26- 0.50 0.51- 0.75 0.76- 1.00 >1.00

Dissolved Fe (nM)(UoP data)

Longitude (Longitude (ooE)E)

Lat

itu

de

(L

atit

ud

e (oo

N)

N)

“IRONAGES”standard

collected here

(Provided by the SeaWiFSproject NASA/Goddard Space

Flight Center, and ORBIMAGE)

Analytical challenge - how to collect, preserve and distribute sea water samples for the preparation of a low level iron in sea water CRM?Paul Worsfold, Nice 2003 lecture

IRONAGES standard: sampling

• 1000 l HDPE cubic tank• Filled to 700 l over 8 h• South Atlantic Ocean, 6.0oS 5.6oW• Acidified to ~pH 2 using 700 ml Q-HCl• Homogenised by gentle shaking of

tank

R.V. PolarsternR.V. Polarstern

Towed fishTowed fish

HDPE tankHDPE tank

Towed fishTowed fish

Paul Worsfold, Nice 2003 lecture

IRONAGES standard: bottling• Transfer from tank to clean

laboratory using Teflon FEP line and peristaltic pump

• 200 x 1 l LDPE bottles filled in two batches - 160 UoP & 40 NIOZ

• Trials underway for:– homogeneity– time-series stability– sample storage

• Other bottles sent to 25 worldwide iron laboratories


IRONAGES standard: participants/methods

Analytical methods used duringAnalytical methods used duringthe IRONAGES exercisethe IRONAGES exercise

Laboratories participating in the “Ironcal”Laboratories participating in the “Ironcal”workshop, San Antonio, January 2000workshop, San Antonio, January 2000

SolventSolventextractionextraction

GFAASGFAAS

FI-CLFI-CL(O(O22, FeII), FeII)

FI-CLFI-CL(H(H22OO22, FeIII), FeIII)

FI-FI-spectrophotometryspectrophotometry

CSV (1N2N)CSV (1N2N)

CSV (SA)CSV (SA)

CSV (TAC)CSV (TAC)

SpectrophotometrySpectrophotometry(long pathlength)(long pathlength)

Isotope dilutionIsotope dilutionICP-MS ICP-MS

Solid phaseSolid phaseextractionextraction

ICP-MSICP-MS

Total: 25Total: 25

AustraliaAustralia

BelgiumBelgium

BermudaBermuda

CanadaCanada

FranceFrance

GermanyGermany

JapanJapan

NetherlandsNetherlands

New ZealandNew Zealand

SwitzerlandSwitzerlandUnitedUnited

KingdomKingdom

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Laboratory data versus analytical method

Jim Moffett, independent chair

0.0

0.4

0.8

1.2

1.6

Analytical method

Fe

co

nce

ntr

ati

on

(n

M)

Data courtesy of Andrew Bowie (University of Tasmania, Australia)

FI-C

L -

Fe(II)

FI-C

L -

Fe(III)

ID-IC

P-

MS

SP

E - IC

P-M

S

SE - G

FA

AS

CS

V (D

HN

)

FI - S

PEC

Overa

ll mean

Mean

s fo

r e

ach

tech

niq

ue


Towards GEOTRACES (GEOSECS II)

• Imbalance of ocean sciences– plenty modeling of the virtual ocean

• armchair oceanography: cheap and easy

– not much real data in real ocean – accuracy, certification, calibration is

underfunded

• need for certified standards• nitrate, phosphate, silicate • essential metals Fe, Mn, Zn, Co, Cd

Summary

• Co-limitation is the rule• Single limiting factor is exceptional• Southern Ocean nice and simple

– only light and Fe as two co-limitations– only two taxa: diatoms and Phaeocystis

• Oligotrophic central gyres– surface waters uncharted for all nutrients– NO3, PO4, SiO4 in nanomoles or picomoles ?– Fe, Mn, Zn, Co, Cu ?– seasonality of these nutrients ?

• New concepts beyond Liebig (1840 !) and M&M (1913 !) are needed– dynamics beyond steady state– co-limitations beyond single factor

The EndWith many thanks for support by

Scientific Committee for Oceanic Research SCOREuropean Union Programs MERLIM, CARUSO, IRONAGES

National Science Agencies (NWO, NERC, DFG, CNRS)Our universities and institutes

Koninklijk Nederlands Instituut voor Onderzoek der ZeeRoyal Netherlands Institute for Sea Research

Europese UnieEuropean Union

Co-Limitation of Phytoplankton by Light and Multiple Nutrients Hein de Baar, Klaas Timmermans, Loes...

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Transcript of Co-Limitation of Phytoplankton by Light and Multiple Nutrients Hein de Baar, Klaas Timmermans, Loes...