Ocean acidificationM. Debora Iglesias-Rodriguez

Based on “An International Observational Network for Ocean Acidification”by Feely et al, and other stories.

Hoegh-Guldberg et al. 2007

Time series of atmospheric CO2

Mauna Loa data: Dr. Pieter Tans, NOAA/ESRL (http://www.esrl.noaa.gov/gmd/ccgg/trends)

HOTS/Aloha data: Dr. David Karl, University of Hawaii (http://hahana.soest.hawaii.edu) (modified after Feely, 2008).

The Federal Ocean Acidification Research and Monitoring (FOARAM) Act passed Congress

(March 25, 2009)

NERC Ocean Acidification Programme

The Natural Environment Research Council and the Department for

Environment, Food & Rural Affairs are developing a collaborative 5 year research programme of ~ £12m.

Emerging and established ocean acidification programmes

• Interactions between biota and water chemistry

• Effects of ocean acidification on marine calcifiers

• Quantify synergistic effects from other environmental variables, (e.g., temp)

• What determines the capacity of organisms to adapt to ocean acidification?

• Threshold levels (tipping points) at the organism and community level

• Societal impacts (socio-economics of ocean acidification) - e.g., effect of declining pteropodpopulations on fish stock?

Central Issues

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

from Pörtner et al., 2004)

Some facts about ocean acidification

• Since industrialization, pCO2 has increased from 280 to 387 ppm: decrease of ~0.1 units at a rate of ~0.0018 yr-1 (Caldeira & Wickett, 2003, 2005; Bates & Peters, 2007; Santana-Casiano et al., 2007).

• pCO2 will reach >800 ppm circa 2100: additional decrease (0.3 pH units).

• Present pCO2 is higher than experienced on Earth for the last 800,000 yrs

• Continuing pCO2 rise will lead to significant temperature increases

Chemistry of ocean acidification

Increasing carbon dioxide (CO2) in seawater causes the formation of carbonic acid (H2CO3), which causes acidification. Effects:

1. [CO2] increase ⇒ ↑ photosynthesis

2. [HCO3-] increase: CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3

- ⇔ 2H+ + CO3

2- ⇒ ↑ calcification

3. [CO32–] decrease, and the ocean’s saturation state with respect to

CaCO3 (calcite/aragonite) (Ω):

Ω = f{[CO32–], [Ca+2]} ⇒↓ calcification

?

Chemistry of ocean acidification

Increasing carbon dioxide (CO2) in seawater causes the formation of carbonic acid (H2CO3), which causes acidification. Effects:

1. [CO2] increase ⇒ ↑ photosynthesis

2. [HCO3-] increase: CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3

- ⇔ 2H+ + CO3

2- ⇒ ↑ calcification

3. [CO32–] decrease, and the ocean’s saturation state with respect to

CaCO3 (calcite/aragonite) (Ω):

Ω = f{[CO32–], [Ca+2]} ⇒↓ calcification

?

Carbonic anhydrase

Carbonic anhydrase

?

Carbonic anhydrase

HCO3- CO2 H2O

Ca+2

ATPase

Carbonic anhydrase

Carbonic anhydrase

?

Carbonic anhydrase

HCO3- CO2 H2O

Ca+2

ATPase

CO32-

CO32-

~2’’

~30’’

pH in intracellular

compartments: 7.2 - 7.8 for

cytosol, nucleoplasm, mitochondria, plastid stroma(Raven, pers

com).

Diatoms

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Riebesell et al., Nature, 2000.

Iglesias-Rodriguez et al., Science, 2008.

Coccolithophores

Phytoplankton functional type adaptation

Langer et al., G32006.

bicarbonatecarbonate

Adaptation???

Acclimation - how?

Adaptation - who wins?

Main questions

• What is the long term adaptation to fast rate of change?

• What is the susceptibility of organisms to changes in pH?

• Can we build an ocean observation network that can accounts for biological complexity?

• Can we improve our knowledge on cell physiology and adaptation with the current experimental approaches?

• What is the effect of functional group dominance on biogeochemistry?

So far:

- Lab experiments

- Mesocosm experiments

- Field observations and monitoring - what latitudes?

Calcium carbonate saturationRoyal Society report on ocean acidification, 2005St. Petersburg report on ocean acidification, 2007

Orr et al., 2005.

CO2 sampling system attached to one of NOAA'sIntegrated Coral Observing Systems (ICON) in the

Bahamas

Joanie Kleypas, NCAR Lead Scientist; �Chris Langdon, and colleagues at the Rosentiel School of Oceanography, University of

Miami; �James Hendee and Rik Wanninkhof, NOAA.

Regional organismal and ecosystemresponse to increased CO2 from

shipboard surveysJust completed 1st August 2009:

On-deck mesocosm ecosystemperturbations with gradients of pH and organic carbon

Responses of phytoplankton and zooplankton to increased CO2 and changingstoichiometry of food supply

Assessment of regional ”natural”stoichiometry of production and export

Richard Bellerby and Frede Thingstad

Community requirements

• A coordinated regional and global network of observations, process studies, manipulative experiments and modelling.

• Identify natural variability of carbonate chemistry.

• Identify whether or not there are geochemical thresholds for ocean acidification that will lead to irreversible effects on species and ecosystems over the next few decades.

• Investigate long-term adaptation.

Strategy:- Repeat surveys of chemical and biological properties- Time-series measurements at stations and on floats & gliders

Measurement Requirements for the Ocean Acidification Observational Network

• DIC, pCO2, TA and pH

• Particulate inorganic carbon (PIC), particulate organic carbon (POC) and bio-optical measurements

• Oxygen

• Other biological measurements (specific DNA sequences for marine bar-coding, physiological rates, genomics and proteomics)

• Nutrients, salinity

Suspended [PIC] (MODIS/ Terra). (a) January–March. (b) April–June. (c) July–September. (d) October–December (after Balch et al, 2007).

Time Series Measurements on Moorings, Gliders and Floats• Carbon and pH sensors on time-series moorings can resolve short space-time scale variability of the upper ocean - OceanSITES time-series.

• Some of these locations: intensified process studies: e.g. open ocean mesocosm experiments, coastal mesoscale CO2 release experiments.

• Coastal sites: effect of upwelling, riverine input - biogeochemical models that address specifically ocean acidification.

• These monitoring systems can provide verification for the models: open ocean large-scale biogeochemical models and coastal data will verify nested high resolution coastal models.

• Carbon system sensors could also be deployed on floats and gliders to resolve shorter space-time scale variability of the upper ocean.

Potential ocean acidification monitoring sites (coral reefs)

Underway Volunteer Observing Ship Network

• Ships equipped with carbon system sensors and ancillary technologies (e.g. autonomous water samplers, nutrient analyzers) for ocean acidification should be added to the present carbon network.• These should be supported with technology to study OA (DNA sensors, PIC and POC production rates, supported by satellite measurements).

New ‘-omics’ approaches

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Dupont et al., 2008.

Meta-approaches

Diversity of marine microbial communities: ‘metagenomics’ (Venter et al. 2004, Delong et al. 2006, Sogin et al. 2006)

Functional properties of marine communities: ‘proteomics’ (Jones, Edwards, Skipp, O’Connor, Iglesias-Rodriguez, 2009)

If cells are in the water, what are they doing?

Genome Genes Static

Proteome Phenes Evolving

proteomics

2.4L 14L 14L

2-3 days in exponential 5/6 generations 3/4 generations

Sampling: Sampling: Sampling:Before addingculture

• SEM • Nutrients• pH• Salinity• Temperature

Before transfer to14L culture

Before starting bubbling

Before addingculture

Before transfer to 14L culture

Before starting bubbling

Before addingculture

Final harvest

• DIC/Alk• Nutrient• pH• Salinity• Temperature

• DIC/Alk• Nutrient• pH• Salinity• Temperature

• DIC/Alk• Nutrient• pH• Salinity• Temperature• PIC• POC• SEM• FRRF

• DIC/Alk• Nutrient• pH• Salinity• Temperature

• DIC/Alk• Nutrient• pH• Salinity• Temperature

• DIC/Alk• Nutrient• pH• Salinity• Temperature• PIC• POC• SEM• FRRF• Proteins foriTRAQ

385 or 1500 ppm CO2

Jones, Edwards, Skipp, O’Connor, Iglesias-Rodriguez, Proteomics, 2009

MembraneOrganelleCytoplasmNucleusUnknown

Subcellular location by protein cluster

Metabolic processNucleosome assemblyPhotosynthesisProtein foldingStress responseTransportProtein synthesisUnknown

Biological process by protein cluster

OA impact on coccolithophores

Improve understanding allows building a range of new modelsAlex Kahl, Oscar Schofield and Debora Iglesias-Rodriguez

Photosynthetic carbon fixation

Carbon Biosynthesis

Carbon Reserves

Light (E)Nutrients

Low C:Nexudate

High C:Nexudate

POC = CPIC is ½ of the POC

when nutrient saturatePOC can vary with nutrients

PIC is constant

Cs

CR : NR

CB : NB

CP : NP

fP

B

fP

R

fB

P

fB

S

fR

B

fN

fE1

fE

2

CP

C+

CB

C+

CS

C+

CR

C= 1

NP

N+

NB

N+

NR

N= 1

dCP = fE − f PB − f PR

dCB = fPB + f RB − f BP − f BR − fBS − f E 2

dCS = fmort ⋅ f BS

dCR = fPR + f BR − f E1

fN =Vmax, N ⋅ Nin

Nin ⋅KN

fE = CR − CE( )⋅ kP ⋅4 ⋅ π ⋅ r 2

4 / 3 ⋅ π ⋅ r 3

⇒3 ⋅ CR − CE( )⋅ kP

r

fL = a∗ ⋅Chl

PQ⋅ PAR ⋅ φP

transfer f function = concentration gradients( )⋅ e−kt

Future challenges for the next ten years

• Assess long term adaptation of functional groups.

• Improve basic knowledge of carbon physiology - adaptation to bicarbonate-rich ocean.

• Observations - coupling between biogeochemistry, physiology, and modelling.

• Building a global time series to assess changes in chemistry and biology.

• Extrapolate from experimental results to natural condition

Acknowledgements

Richard Bellerby, University of Bergen.

Richard Feely, NOAA, Seattle, U.S.A.

Jean-Pierre Gattuso, Laboratoire de Villefranche, France.

Richard Lampitt, National Oceanography Centre, Southampton, U.K.

John Raven, University of Dundee, U.K.