Ocean AcidificationRepasado por Profa. Furumo
The Situation• Current atmospheric CO2 value is about  380ppmv compared to 280ppmv before the  industrial age• 1/3 of anth...
Chemical Calisthenics• Inorganic carbon system largely controls pH of  seawater• DIC (Dissolved Inorganic Carbon) exists i...
The Process• Calcium carbonate (CaCO3) is required by  calcifying organisms to make shells• Increased CO2 = decreased [CO3...
Does this effect all organisms equally?• The CaCO3 saturation state (Ω) determines the  extent to which organisms are affe...
AragoniteSaturationHorizon (ASH)
Shoaling of Aragonite Saturation            Horizon
Danger Zones• Temperature decrease = Increase in solubility  of CaCO3• Coupled with ASH migration• Higher latitudes most v...
Results of Acidification on Fauna•   Widespread ecological implications•   Decreased organism calcification capabilities• ...
Impact on Fauna• Ecological Cascade beginning with plankton• 3 primary CaCO3 producers• Coccolithophores and Foraminifera ...
Pteropod C. pyramidata• Habitat extends up to 55˚N• Found at 400-500m depth during day and  surface at night – Diel Vertic...
New Food Menu• Gymnosomes prey exclusivelyon shelled pteropods, so wouldhave to seek a new habitat in their absence• Zoopl...
Pink salmon example• Euthecosome L. helicina  account for about 60% of  juvenile pink salmon,  before they switch to C.  p...
Benthic organisms• High commercial value (oysters, mussels)• Most vulnerable during larval and early  calcifying stages  –...
Results of Acidification on Fauna•   Widespread ecological implications•   Decreased organism calcification capabilities• ...
Mechanisms in response to             hypercapnia• Increased pCO2 diffuses  into intra-/extra-cellular  spaces, causing de...
Physiological Adaptations• Metabolism suppression   – Short-term advantage,     long-term danger   – Shuts down expensive ...
Blood-Oxygen Binding• Higher metabolic rates among organisms  require more pH sensitive oxygen binding in  the blood• Epip...
Does anybody win?• Tolerant fish – “fish mortality caused by  anthropogenic CO2 is never expected in  marine environments”...
Lets discuss• What do you think the effects of acidification  are on coastal environments?• Which organisms (or which habi...
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Paper discussion Fabry et al. 2008

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Impacts of ocean acidification on marine fauna and ecosystem processes presented by Paul Furumo.

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Paper discussion Fabry et al. 2008

  1. 1. Ocean AcidificationRepasado por Profa. Furumo
  2. 2. The Situation• Current atmospheric CO2 value is about 380ppmv compared to 280ppmv before the industrial age• 1/3 of anthropogenic CO2 is absorbed by the seas• Elevated partial pressure of carbon dioxide (pCO2) interferes with organisms ability to calcify structures and their metabolic physiology
  3. 3. Chemical Calisthenics• Inorganic carbon system largely controls pH of seawater• DIC (Dissolved Inorganic Carbon) exists in 3 primary forms, and at pH 8.2: – 1) bicarbonate ion (HCO3-) – 88% – 2) carbonate ion (CO32-) – 11% – 3) aqueous carbon dioxide (CO2(aq)) – 0.5%
  4. 4. The Process• Calcium carbonate (CaCO3) is required by calcifying organisms to make shells• Increased CO2 = decreased [CO32-] & pH• Increased CO2 yields fewer carbonate ions available to form CaCO3 through the reaction: CO2 + CO32- + H2O = 2HCO3-
  5. 5. Does this effect all organisms equally?• The CaCO3 saturation state (Ω) determines the extent to which organisms are affected• Based on whether organism secretes shells in form of aragonite or calcite, 2 forms of CaCO3• If Ωarag or Ωcal > 1, formation of shells favored• If Ωarag or Ωcal < 1, dissolution is favored• Importance of saturation states, ΩCaCO3 dictates calcification instead of pH
  6. 6. AragoniteSaturationHorizon (ASH)
  7. 7. Shoaling of Aragonite Saturation Horizon
  8. 8. Danger Zones• Temperature decrease = Increase in solubility of CaCO3• Coupled with ASH migration• Higher latitudes most vulnerable• Pelagic organisms also at risk• Coastal habitat uncertain due to dynamic nature of circulation and eutrophication factors
  9. 9. Results of Acidification on Fauna• Widespread ecological implications• Decreased organism calcification capabilities• Developmental complications• Altered species distribution• Change in diet/prey choices• Physiological adaptations
  10. 10. Impact on Fauna• Ecological Cascade beginning with plankton• 3 primary CaCO3 producers• Coccolithophores and Foraminifera = calcite excretion, produce majority of pelagic CaCO3• Euthecosomatous pteropods = aragonite excretion, 50% more soluble in seawater
  11. 11. Pteropod C. pyramidata• Habitat extends up to 55˚N• Found at 400-500m depth during day and surface at night – Diel Vertical Migration• Provide major source of CaCO3 to ocean interior & deep ocean, biological pump• Shoaling ASH restricting its habitat distribution• Will have to adapt to aragonite under- saturation or migrate to warmer, carbonate rich water
  12. 12. New Food Menu• Gymnosomes prey exclusivelyon shelled pteropods, so wouldhave to seek a new habitat in their absence• Zooplankton and carnivorous fish (cod, haddock) that feed on pteropods would have to find new prey, such as juvenile fish
  13. 13. Pink salmon example• Euthecosome L. helicina account for about 60% of juvenile pink salmon, before they switch to C. pyramidata in third year of life• Models predict that a 10% decrease in pteropod production could result in a 20% drop in pink salmon body weight
  14. 14. Benthic organisms• High commercial value (oysters, mussels)• Most vulnerable during larval and early calcifying stages – More soluble shell precursors – Transient, unstable forms of CaCO3 – Ex) Amorphous CaCO3, high-magnesium calcite
  15. 15. Results of Acidification on Fauna• Widespread ecological implications• Decreased organism calcification capabilities• Developmental complications• Altered species distribution• Change in diet/prey choices• Physiological adaptations
  16. 16. Mechanisms in response to hypercapnia• Increased pCO2 diffuses into intra-/extra-cellular spaces, causing decrease in pH• Methods to counteract internal acidification:1) Passive buffering2) Transport and exchange of ions3) Transport of CO2 in the blood4) Metabolic suppression
  17. 17. Physiological Adaptations• Metabolism suppression – Short-term advantage, long-term danger – Shuts down expensive processes like protein synthesis• Ex: Sipunculus nudus, a tidal worm, reduces metabolism under short- term CO2 elevation; over long-term (3-6 weeks), 100% mortality
  18. 18. Blood-Oxygen Binding• Higher metabolic rates among organisms require more pH sensitive oxygen binding in the blood• Epipelagic squid with high metabolisms could be impacted by increased CO2 present in the oceans as it interferes with O2 binding at the gills
  19. 19. Does anybody win?• Tolerant fish – “fish mortality caused by anthropogenic CO2 is never expected in marine environments”• Jellyfish frequency increase with pH decrease• Will calcifying organisms eventually be replaced by non-calcifiers? i.e. Algae
  20. 20. Lets discuss• What do you think the effects of acidification are on coastal environments?• Which organisms (or which habitats) seem to be most at risk from ocean acidification?• Can acidification occur in freshwater systems?• What other possible solutions exists beyond simply reducing CO2?• Is ocean acidification unavoidable given our daily habits?
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