Rising Atmospheric CO 2 & Ocean Acidification
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Rising Atmospheric CO 2 & Ocean Acidification Scott Doney Woods Hole Oceanographic Institution International SOLAS Open Science Conference (May 2012) Special Thanks To: Alan Barton, Wei-Jun Cai, Sarah Cooley, Richard Feely, Hauke Kite-Powell, Noelle Lucey, Rik Wanninkhof Talk Outline -Ocean CO 2 Uptake & Seawater Chemistry -Biological, Ecological & Biogeochemical Effects -Socio-economic Impacts
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Rising Atmospheric CO 2 & Ocean Acidification . Scott Doney Woods Hole Oceanographic Institution International SOLAS Open Science Conference ( May 2012). Talk Outline -Ocean CO 2 Uptake & Seawater Chemistry -Biological, Ecological & Biogeochemical Effects -Socio-economic Impacts. - PowerPoint PPT Presentation
Transcript of Rising Atmospheric CO 2 & Ocean Acidification
Rising Atmospheric CO2 & Ocean Acidification
Scott Doney Woods Hole Oceanographic Institution
International SOLAS Open Science Conference (May 2012)
Special Thanks To: Alan Barton, Wei-Jun Cai, Sarah Cooley, Richard Feely, Hauke Kite-Powell, Noelle Lucey, Rik Wanninkhof
Talk Outline-Ocean CO2 Uptake & Seawater Chemistry-Biological, Ecological & Biogeochemical Effects-Socio-economic Impacts
“Thus human beings are now carrying out a large scale geophysical experiment…”Revelle and Suess, Tellus, 1957
Rising Atmospheric CO2
-strong evidence for human causation-highest level in at least last million years-rapid change in CO2 relative to natural trends
Ice core data
2−[CO3 ][CO2]
100−150% 50%
2100
8.2
8.1
8.0
7.9
7.81800 1900 2000 2100
50
40
30
20
10
0
300
240
180
120
60
0
pHμm
ol kg−1
Year
pH
CO2(aq)
CO32−
30% acidity16% [CO3 ]
2000
2−
Wolf-Gladrow et al. (1999)
Ocean Acidification
CO2 + H2O H2CO3 H+ + CO32- HCO3
-H+ + HCO3-CO2 + CO3 + H2O2- 2HCO3-−−<>−−
Hawaii Ocean Time-Series
Doney et al. Ann. Rev. Mar. Sci. 2009Dore et al. PNAS 2009
-Observed rising CO2 & declining pH
CO2 Effects on CaCO3 Saturation aragonite
= [Ca2+][CO32-] / Ksp
Δ[CO32-] = [CO3
2-]obs - [CO32-]sat
Orr et al. Nature 2005; Steinacher et al. Biogeosci. 2009
Present 2100
Anthropogenic Fluxes of CO2, N and SSO2 & H2SO4Anthro CO2
NH4 HNO3
Doney et al. PNAS 2007
Nutrient Eutrophication & Hypoxia
more nutrients
-organic matter respiration lowers pH & O2
-coastal & estuarine waters low pH & buffering capacity-high natural variability
Cai et al. Nat. Geosci. 2011
High Frequency Natural Variability
Hofmann PLoS 2011
Open Ocean AntarcticOpen Ocean
Upwelling Estuarine/near shore
Coral Reef Kelp Forest
Possible Biological Impacts Corals: warm & cold-water
lobsters, crabs some plankton
pteropodsplanktonic snails
scallops, clams, oysterscold-water corals
-Reduced shell formation • corals, mollusks, some
plankton, (crustaceans)-Habitat loss• coral & oyster reefs-Less food for predators• humans, fish, whales-More seagrasses & algae-Finfish sensory & behavior-Open questions• organism ability to adapt• food-webs & ecosystems
Meta-Analysis of Biological Impacts
Kroeker et al. Ecology Letters 2010
Hall-Spenser et al. Nature 2008; Fabricius et al, Nature Clim. Change 2011
‘low pCO2’: pH 8.1∼ ‘high pCO2’: pH 7.8–8.0
intense vents: pH <7.7
Natural High CO2 Laboratories
Potential Food Web Impacts
Barrie Kovish
Vicki Fabry
Pacific Salmon
Coccolithophores
Pteropods
V. Fabry
Copepods
Reduced pH Impairs Sensory Responses & Alters Behavior
Munday et al. PNAS (2009); Dixson et al. Ecol. Lett. (2010); Nilsson et al. Nature Climate Change (2012)
-Sense of smell & hearing-Predator avoidance & mortality-Change in acid-base balance alters effects of neurotransmittor
control CO2
-Nitrogen cycle• N2 fixation (++)• Nitrification (-)-Carbon cycle• Photosynthesis (+)• Calcification (- -) • CaCO3 dissolution (++)
-Export production• Carbon/nutrient ratio (-) or (+)• Particle ballasting (?)• Subsurface oxygen (-) or (?)-Trace gases• DMS (?)• N2O (+) or (?)• Organohalogens (?)-Trace metal speciation
Biogeochemical Impacts in Planktonic Systems
Hutchins et al. Oceanogr. 2009Gehlen et al.; Hopkins et al.; and Riebesell & Tortell in Gattuso & Hansson 2011
Social & Economic Impacts
Cooley et al. Oceanography (2009)Cooley & Doney, Environmental Research Letters (2009)Cooley et al. Fish & Fisheries (2012)
-Marine fisheries & aquaculture• food supply• jobs, livelihoods & trade-Coral reefs• reef fisheries• tourism• shoreline protection-Globally, largest impacts may be on developing island and coastal nations• exposure, sensitivity &
adaptive capacity
-Coastal upwelling => Low oxygen & acidification
-Commercial oyster hatcheries a $100M industry (3000 Jobs)-But no natural Pacific oyster recruitment in WA state for past decade & many hatchery failures
Regional Impacts: Pacific NW Oysters
Reduced Larval Production During Upwelling Events
Barton Limnology & Oceanography 2012
Saturation State
Oyster Larval Production vs. Saturation State
TemperaturepH
Upwelling Winds
Doney Science 2010
Synergies with Other Human Perturbations
Scott DoneyWoods Hole Oceanographic Institution [email protected]
Special Thanks To: Alan BartonHauke Kite-PowellRik Wanninkhof
-Seawater Chemistry• Well understood for open-ocean • Additional factors in coastal waters• Emerging observing systems-Ocean Biological Impacts• Impact corals & mollusks• Ability to acclimate & adapt?• Habitat decline & food-web effects• Synergies with other stressors (e.g.
climate change, overfishing)-Biogeochemical Cycles• Nitrogen, carbon & trace gases-Socio-economic Impacts• Wild fisheries & aquaculture • Recreation, tourism, ecosystem &
cultural services
Summary & Future Directions
Rising CO2 & Ocean Acidification
-About 1/3rd of human carbon dioxide emissions end up in the ocean-Locally enhanced in some coastal waters by atm. deposition, excess nutrient inputs, circulation-Well-understood changes in seawater chemistry:• more acidic (lower pH)• higher aqueous CO2
• lower carbonate ion -Rates of change fast, ~100x faster than natural
