Climate, Oceans and Phytoplankton:

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Climate, Oceans and Phytoplankton That Sinking
Feeling
Conservation Biology Oct 22, 2004
With apologies to Bill Forsyth and Jorge
Sarmiento (Nature 2000)
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Our plan for today

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

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Our plan for today

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

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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

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Global Carbon Cycle
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CARBON CYCLE ISSUES
Roger Revelle
360
CO2 (ppm)
the grandfather of the greenhouse effect...
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• 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...

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DEEP WATERS are Undersaturated with CO2
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Absorption of CO2 in the Ocean new and void
CO2 (aq) CO2 Ca2 CaCO3 (ppt) (reactive,
catalytic)
?pCO2 -22 39 -20
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CARBON SEQUESTERING - a PANACEA?
Depth
Case 2
Case 1
PSN
100
1000
Organic carbon
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Depth
Option 1 Carbon Sequestering injection
100
P
1000
Inorganic CO2
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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 water circulation
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• Movement
• Uncertain effects on
• benthic communities
• Transportation and
• processing costs

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Depth
Option 2 Carbon Sequestering Biological pump
PSN
100
1000
Organic carbon
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IRON LIMITATION IN MARINE SYSTEMS
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John Martin
Linked PHYTOPLANKTON PRODUCTIVITY With the CARBON
CYCLE
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 Ill create the
  next ice age.

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Nitrate
Cell Biomass growth ? needs (C, N, P, ?)
Phosphate
Silicate
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Nitrate
Cell Biomass growth ? needs (C, N, P, Fe)
Redfield ratio 106161 0.008 CNPFe
(cellular) So for every gram of iron added,
draw down 2.9 tonnes of carbon.
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So what is limiting the growth of the
phytoplankton?
FeSO4 Fe2 SO4-2 Fe3 Fe(OH)x (ppt)
Concentration mol L-1
Residence Time in Upper Waters (years)
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How does iron get to the Pacific?
April 2001
http//science.nasa.gov/headlines/y2001/ast17may_1
.htm
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CLEAN sampling and handling techniques
Martins Small Bottle-experiments (small scale)
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Meso-scale studies to test the iron
hypothesis Does adding iron stimulate the growth
of phytoplankton?
IronExII
SOFeX
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SOFeX - 64 km2 with 1 nM FeSO4
... So, some ecosystems have major Nutrients
() but limiting levels of Iron (cheap!)
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Quantifiable reduction in atmospheric CO2 in
"patches" of iron 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.
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Started with a mixed flagellate and diatom
community
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Ended with a DIATOM-only community.
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Remove CO2 via Productivity
SINK! Biological Pump!
IronExII
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Meso-scale studies to test the iron
hypothesis Does adding iron stimulate the growth
of phytoplankton?
IronExII
SOFeX
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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)
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SERIES fertilization of Ocean Station PAPA
(2002) Funded through SOLAS (NSERC, CCAF etc.)
Iron fertilization to measure Growth, gas
production, sinking 64 sq. km FeSO4 addition
1-2 nM Fe in the surface water
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SERIES fertilization of Ocean Station PAPA
(2002) Funded through SOLAS (NSERC, CCAF etc.)
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SERIES fertilization of Ocean Station PAPA
(2002) Funded through SOLAS (NSERC, CCAF etc.)
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FeSO4 and SF6 (gas)
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SERIES fertilization of Ocean Station PAPA (2002)
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In warm waters ...
FeSO4 SO4-2 Fe2 Fe3 Fe(OH)x (ppt)
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In warm waters ... But the cold waters of the
North may be a different story
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CO2
CO2 CH4 DMS N2O
Different story
FeSO4 SO4-2 Fe2 Fe3 Fe(OH)x (ppt)
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Consequences of fertilizing OS PAPA ...

• Few Diatoms, lots of flagellates.
• Flagellates were stimulated to grow
• Respire at gt 90 of carbon
• Produce GHG that are more destructive than CO2
• The resulting phytoplankton are a bit suspect ....

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.... 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.

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One flagellate that dominated is ....
Responsible for Paralytic Shellfish
Poisoning (PSP)
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One of the diatoms that dominated was ...
Chaetoceros sp. (a non-specific fish kill
species)
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Another was Pseudo-nitzschia
a toxigenic diatom which produces domoic acid -
responsible for Amnesiac Shellfish
poisoning (ASP) in local waters
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Conclusions so far.

• Theres 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.

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Public ponderingson scientific responsibility.

• There are many of us who consider the oceans to
  be sacred. Weve 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