Climate, Oceans and Phytoplankton: That Sinking Feeling* *With apologies to Bill Forsyth and Jorge...

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Climate, Oceans and Phytoplankton: That Sinking Feeling*

*With apologies to Bill Forsyth and Jorge Sarmiento (Nature 2000)

Conservation BiologyOct 22, 2004

Our plan for today:

• Conservation and the ocean.• Why? Global carbon budget.• How? Carbon sequestration: injection• How? Carbon sequestration:

“biological pump”

Our plan for today:

• Conservation and the ocean.• Kyoto• Carbon credits.

How the oceans influence climate

• Oceans and atmosphere are tightly linked.• Oceans are critical for storing heat (and

carbon)• Powerful currents are moving waters -

transporting heat• Deep-water currents influence extremes in

climate• Minor changes in ocean current mean

major (large scale) climate variations

Global Carbon Cycle



Roger Revelle

“the grandfather of the greenhouse effect...”

40% of the atmospheric carbon remains in the atmosphere.2/3 from fossil fuel; 1/3 from clear of forests.

Sent warning of sea level changes due to greenhouse effect...

CARBON CYCLE ISSUES

310

360

CO

2 (p

pm)

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DEEP WATERS are Undersaturated with CO2


Absorption of CO2 in the Ocean: “new” and “void”

CO2 (aq)

CO2 + Ca+2

CaCO3 (ppt)(reactive, catalytic)

pCO2 -22 +39 -20 +10

CARBON SEQUESTERING - a PANACEA?

100

1000

Depth

Organic carbon

PSN

P

Inorganic CO2

Case 2Case 1

100

1000

Depth

P

Inorganic CO2

Option 1 Option 1 Carbon Carbon Sequestering: Sequestering: injectioninjection

Option 1 Carbon Sequestering: injection

• Peter Brewer (MBARI)

• Collection of CO2 gases from industry

• Pump to below 1000 m.

• CO2 gases will be denser than seawater and will remain as a liquid or as ice.

• Movement depends on mid- or deep-water circulation.


Plume formation and watercirculation


• Movement• Uncertain effects on benthic communities• Transportation and processing costs

Option 2 Option 2 Carbon Sequestering: Carbon Sequestering:

Biological pumpBiological pump100

1000

Depth

Organic carbon

PSN

IRON LIMITATION IN MARINE SYSTEMSIRON LIMITATION IN MARINE SYSTEMS


John Martin

“Johnny Ironseed”

Looked at the oceans with an analytical eye.... Developed an analytical approach that opened up a

field of ocean chemistry “Give me half a tanker, and I’ll create the next ice age.”

Linked PHYTOPLANKTON PRODUCTIVITYWith the CARBON CYCLE





Phosphate Silicate

Nitrate


Cell Biomass + growth = ∑ needs (C, N, P, ?)



Nitrate


Cell Biomass + growth = ∑ needs (C, N, P, Fe)

Redfield ratio: 106:16:1: 0.008 C:N:P:Fe (cellular)

So … for every gram of iron added, draw down 2.9 tonnes of carbon.

So what is limiting the growth of the phytoplankton?

Residence Time in Upper Waters (years)

Con

cent

rati

on m

ol L

-1

FeSO4

Fe+2 + SO4-2

Fe+3

Fe(OH)x (ppt)

http://science.nasa.gov/headlines/y2001/ast17may_1.htm

How does iron get to the Pacific?

April 2001


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QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.“CLEAN” sampling and handling techniques

Martin’s Small Bottle-experiments(small scale)

Meso-scale studies to “test” the iron hypothesis:Does adding iron stimulate the growth of phytoplankton?

IronExII

SOFeX


QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.SOFeX - 64 km2 with 1 nM FeSO4

... So, some ecosystems have major Nutrients ($$$) but limiting levels of Iron (cheap!)

Quantifiable reduction in atmospheric COQuantifiable reduction in atmospheric CO22 in "patches" of iron in "patches" of iron

fertilization. SOFEX. fertilization. SOFEX.

Watson, A.J., and others. 2000. Effect of iron supply on Southern Ocean CO2 uptake and implications for glacial atmospheric CO2. Nature 407: 730 - 733.


Started with a mixed flagellate and diatom community

Ended with a DIATOM-only community.


IronExII

SINK! Biological Pump!

Remove CO2 via Productivity

Meso-scale studies to “test” the iron hypothesis:Does adding iron stimulate the growth of phytoplankton?

IronExII

SOFeX


To get the Biological Pump ... Pumping, need to grow diatoms and other heavy cells. Does the addition of iron always result in these heavy cells?


Good (sp. density 1.1)...

Better (sp. density 1.5)...

Terrible! (sp. density 1.1)


SERIES: fertilization of Ocean Station PAPA (2002)Funded through SOLAS (NSERC, CCAF etc.)

Iron fertilization to measure:Growth, gas production, sinking

64 sq. kmFeSO4 addition~ 1-2 nM Fe in the surface water

SERIES: fertilization of Ocean Station PAPA (2002)Funded through SOLAS (NSERC, CCAF etc.)

FeSO4 and SF6 (gas)

SERIES: fertilization of Ocean Station PAPA (2002)

In warm waters ...

FeSO4

SO4-2 + Fe+2

Fe+3

Fe(OH)x (ppt)

010203040

02468101214DayNutrient (µM), Chl a (µg/L)SilicateNitrateChl aIn warm waters ... But the cold waters of

the North may be a different story

Different story

FeSO4

SO4-2 + Fe+2

Fe+3

Fe(OH)x (ppt)

CO2 CO2 CH4 DMS N2O

Consequences of fertilizing OS PAPA ...

• Few Diatoms, lots of flagellates.• Flagellates were stimulated to grow

Respire at > 90% of carbon Produce GHG that are more destructive

than CO2

• The resulting phytoplankton are a bit suspect ....

.... HARMFUL ALGAL BLOOMS

The definition of a HAB is not clear-cut, since it is a societal term, not a scientific term, that describes a diverse array of blooms (both macroscopic and macroscopic) that can cause detrimental effects to national economies.

Responsible for Paralytic Shellfish

Poisoning(PSP)

One flagellate that dominated is ....

Chaetoceros sp. (a non-specific fish kill species)

One of the diatoms that dominated was ...

Another was Pseudo-nitzschia …

a toxigenic diatom which produces domoic acid - responsible for Amnesiac Shellfish poisoning (ASP) in local waters

There’s no great degree of success.•chemistry of iron limits use at different zones

The measurement of success is uncertain.

The consequences of fertilization may be detrimental at the regional scale

•HABs•toxins

May show no net benefit to GHG emissions.•CO2 respired quickly•O2 stress in surface waters•CH4, DMS and N2O produced.

Conclusions … so far.

Public ponderings…on scientific responsibility.

“There are many of us who consider the oceans to be sacred…. We’ve let the cat out of the bag. We have to keep looking at it now whether we like it or not.”

- Ken Coale

“The biggest danger, in my view, is that large-scale iron fertilization will occur without the necessary understanding of just what will happen on scales ranging from single cells to ecosystems.”

- John Martin

Climate, Oceans and Phytoplankton: That Sinking Feeling* *With apologies to Bill Forsyth and Jorge...

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