DETERMINING THE EFFECTS OF CO2 OCEAN DISPOSAL ON DEEP-SEA ORGANISMS

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Changing the world one breath at a time
Humans, Climate, and Ocean Ecosystems
Ricketts Memorial Lecture Jim Barry Monterey
Bay Aquarium Research Institute
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Changing the world one breath at a time
Humans, Climate, and Ocean Ecosystems

• Collaborators
• Peter Brewer, Kurt Buck, Christian Levesque,
  Eric Pane, Craig McClain, Jim Kennett (UCSB),
  Jeff Drazen (UH), Dave Thistle (FSU), Kevin
  Carman (LSU) , Rafe Sagarin, Chuck Baxter, Sarah
  Gilman, George Somero
• Support
• MBARI
• U.S. Dept. of Energy
• Hopkins Marine Station
• Acknowledgements
• Patrick Whaling, Chris Lovera, Linda Kuhnz,
  Peter Walz, Ed Peltzer
• MBARI Marine Operations ROV groups

Plan for today

• CO2 on Earth and the role of man
• Warming and ocean ecosystems
• The high CO2 ocean
• Challenges for animal physiology
• CO2-related research
• Implications for future ocean ecosystems
• Where do we go from here?

Classic view of human evolution
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Changing the world one breath at a time
Humans, Climate, and Ocean Ecosystems
Plan for today

• CO2 on Earth and the role of man
• Warming and ocean ecosystems
• The high CO2 ocean
• Challenges for animal physiology
• CO2-related research
• Implications for future ocean ecosystems
• Where do we go from here?

Modern view of human evolution?
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Change in Atm. CO2 during the last 550 million
years

• Large variation in CO2, with decline to low
  values over the past 150 million y
• CO2 levels typically change slowly
• Mass extinctions occur during periods of rapid
  climate change (CO2)

   
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The Global Carbon Cycle
A review to help us understand our role
The numbers are Billions of tons of Carbon (1 ton
of Carbon 3.7 tons of CO2)
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Role of Human Activities in the Carbon Cycle
How has our carbon footprint changed?
CO2 Emissions
World Population
Fossil Fuel CO2
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Role of Human Activities in the Carbon Cycle
How has our carbon footprint changed?
Per Capita CO2 Emissions
Per Capita CO2 Emissions (T/y)
Fossil Fuel CO2
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Role of Human Activities in the Carbon Cycle
How has our carbon footprint changed?
Human CO2 emissions as a percentage of global C
budget?
Per Capita CO2 Emissions (T/y)
Fossil Fuel CO2
Fossil fuel emissions are not recycled
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Climate Response 1.0 - 4.5 oC per doubling of
CO2
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Scale of Ocean Climate Variability
3-12 years
25 years
Centuries?
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How is global warming affecting ocean ecosystems?
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Climate-related shifts in rocky intertidal
animals (1932-1993)
Warming of water temperatures over 60 years has
been accompanied by a shift in the geographic
ranges of species
More
Monterey
Less
Warming prediction Species ranges should
migrate poleward with warming temperatures
Northern Species Declined
Southern Species Increased
Barry et al. 1995, Sagarin et al. 1999
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Changes in Fish Communities in the Channel
Islands, California
Conclusions Northern Species decreased Southern
Species increased
Are observed changes a response to short-term
climate variation or long-term climate warming?
Holbrook et al. 2002
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Ecosystem Impacts Coral Reefs
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Mass coral bleaching caused by thermal stress

1. 95 correlation with increases in sea temperature
   (1-2oC above long-term summer sea temperature
   maxima) and bleaching.
2. Backed up experimentally
3. Basis for a highly predictive SST program at NOAA
   (HotSpots)

1998
2002
Strong, Hayes, Goreau, Causey and others
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Threshold temperature above which bleaching
manifests itself (1-2oC above the long-term
summer maximum temperatures WHAT DOES THE
FUTURE HOLD?
Hoegh-Guldberg (1999)
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The High CO2 Ocean
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Rising Atmospheric CO2 and Ocean Chemistry
As ocean CO2 levels increase, so does the acidity
of the oceans
Ocean CO2 level near Bermuda
Atmospheric CO2, Mauna Loa
Ocean Carbon Dioxide umoles C
Keeling
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Ocean CO2 Disposal Today
Sabine et al. (2004)
Projected change in Ocean pH

• Fossil fuel signal has penetrated to gt1000
  2000m
• We have disposed of 118 billion tonnes of C in
  the world ocean
• Global surface ocean CO2 disposal is now 1
  million tons per hour

Caldeira and Wickett (2003)
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Effect of Recent CO2 Emissions on Ocean Chemistry
CO2 on Earth
425,000 Year History of Change

• CO2 emissions causing rapid and
  significant change in ocean chemistry
• Ocean surface is 25 more acidic than
  50 y ago
• Ocean acidification will intensify in
  future

Global CO2 Increase
Atmospheric CO2 (ppm)
Sea Cucumber (Scotoplanes)
Increase in Ocean Acidity due to added CO2
Ocean pH (units)
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Ocean Acidification Sciencea new field

• Carbon storage potential of the oceans?
• Chemistry physics of CO2
• Modeling of CO2 Injection
• Effectiveness of carbon storage methods
• Environmental Consequences of High Ocean CO2
• Effects of ocean iron fertilization
• Response of ocean ecosystems
• Sensitivity of shallow and deep species

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Physiological stress associated with high CO2

• Physiological Challenges
• Reduced Calcification
• Impaired carbonate formation in more acidic
  ocean
• Respiratory Stress
• Reduced oxygen carrying capacity
• Acidosis
• Disruption of acid/base balance
• Metabolic DepressionReduced activity (torpor)

Starothuethus deep-sea octopus
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Reduced Calcification
Normal CO2
Pteropod Mollusk
High CO2
Riebesell et al 2000
Corals

• Ocean acidification will effect calcification
• for may species
• Clams, Snails, Sea Stars, Urchins, Crabs,
  Shrimp, Others
• Consequences not fully understood

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Response of Coccoliths to Recent Climate Change
Iglesias-Rodriguez et al., 2008

• During recent pCO2 increase
• Size of N. Atlantic coccoliths increased
• Species composition remained constant

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Non-lethal damage can affect populations
Pre-Industrial Ocean
Cost of Living
Growth
Energy Budget
Reproduction

• Consequences of Higher Cost of Living
• Individuals
• Slower growth
• Smaller size
• Reduced reproduction
• Lower survival?
• Populations
• Lower population growth rate
• Reduced resilience
• Reduced abundance?
• Greater possibility of extinction?

• Cost of Living
• Respiration
• Digestion
• Activity (movement)
• Acid-base balance
• Immune system
• Etc.

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Are CO2-related stresses severe for deep-sea
animals?
Deep-Sea Animals
pH variation in the Pacific Ocean

1. Reduced metabolic rates
2. Reduced enzyme function
3. Evolved in highly stable deep-sea environment
4. Food-limited Living on the edge

Less Acidic
More Acidic
Future Ocean
Depth (m)
Deep-sea Octopus
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Ocean acidification research examples
Mesocosm Experiments - Bergen
MBARIs R/V Western Flyer
Advanced Benthic Chamber Systems
MBARI ROV Tiburon
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Deep-Sea CO2 Release Experiments

• 3600 m (12,000 ft.)
• Effects of CO2-rich seawater on animals
• Initial studies of effect of deep-sea
  CO2 storage

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Effect of CO2 on Sea urchin survival
Results of deep-sea CO2 release experiments
Distant from CO2 - Most urchins in good
condition Near CO2 - Poor condition, dead,
eroded
Post-Experiment Urchin Condition
Urchins in cage near CO2 pool
CO2 Pool
Control
3600 m ( gt 2 miles deep)
Barry et al. 2003, 2004
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Controlled-gas Aquarium System for lab-based
studies of CO2 tolerance

• Control of temperature, oxygen, carbon dioxide
  for
• Effects of changing oxygen, CO2 levels on
• Growth rates, respiration,
  physiology

Barry et al. 2008
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CO2 tolerance by Decapod Crabs

• How tolerant are shallow and deep-living species
  of CO2 stress?
• Does ambient oxygen availability influence CO2
  tolerance?

Tanner Crab (deep-sea)
Dungeness Crab (shallow water)
NBB
Pane and Barry, 2007
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Brachiopod - Laqueus californianus

• Sessile filter feeders
• Low metabolic rate
• CaCO3 shell, calcareous skeleton
• Unbuffered organism

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Evidence for CO2-related extinctions in the
fossil record
Knoll et al. 1996
Major loss of CO2-sensitive genera
Extinctions

• Major volcanism
• at end of Permian
• high CO2 levels in atmosphere

Low metabolic rates, limited respiration system
Higher metabolic rates, gills, circulation system
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Control n7, pH 6.7 n12

• Brachiopod Response to
• a High CO2 Ocean
• Limited control of internal acid-base balance
  (cant defend internal pH under high CO2)
• Reduced oxygen-carrying capacity under acid
  conditions (strong Bohr effect on brachiopod
  hemerythrin)

pH
unity
Control
unity
pCO2
Control
HCO3-
unity
Control
Manwell, 1960
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Technology for Free Ocean CO2 Enrichment
Experiments

• Analog of terrestrial FACE facilities for plant
  community studies
• Long-term studies of CO2 tolerance for marine
  animals
• Survival, growth, reproduction, larval
  development, physiology

Wisconsin FACE Site
MBARI FOCE Prototype
Acid Storage
pH Sensors
Control Volume
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The future for ocean ecosystems?
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Present Ocean Food Web Diverse, Complex,
Productive
Primary Producers
What are the expected effects of ocean
acidification on ocean ecosystems?
Zooplankton food web
Upper Trophic levels
Sinking Organic Debris
Microbial Remineralization
Seafloor community
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Future Ocean Food Web Loss of biodiversity, low
productivity, dominated by microbial recycling?
Primary Producers

• Reduced Biodiversity
• Simplified Food Web
• Increased Microbial Dominance?

Upper Trophic levels
Zooplankton food web
Sinking Organic Debris
Microbial Remineralization
Seafloor community
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Effects of Ocean Acidification on Ocean Food Webs

• Ocean Acidification
• Reduced shell formation in pteropods
• Reduced growth survival of pteropods
• Disruption of Salmon Food Web
• Cascading effects for higher predators (mammals,
  humans)

Pteropod Salmon food
Sockeye Salmon
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Biodiversity affects the function of Large
Marine Ecosystems (LMEs)

• LMEs with lower biodiversity have
• Lower catch
• More fishery collapses
• More variation

• Reduced biodiversity due to acidification/warming
  may cause
• Cascading collapse reorganization of food
  webs
• Increased variation in production, reduced
  stability
• Impaired potential for recovery (reduced
  resilience)

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Ocean Warming - Summary

• What we know
• Warming leads to increased stratification of
  surface waters
• Sea level will rise
• Thermal expansion glacial ice melt
• Redistribution of faunal ranges (poleward
  migration )
• Thermal stress for some groups (corals)
  severe
• Small event in Earth history, but large
  event in human history
• What we expect
• Reduced ocean productivity
• Increase possible / probable at high latitudes
• Expansion of oxygen minimum zones
• Shifts in marine food webs
• Loss of coral reefs
• What we dont know
• Ability of animals to acclimate or adapt to
  climate-induced changes
• Tipping points for disruption of ecosystem
  function
• Production and stability of marine fisheries

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Ocean Acidification - Summary

• What we know
• Ocean CO2 influx from atmosphere is ongoing,
  massive
• Scale of change small for Earth history, but
  extreme for recent geologic history
• Physiological stress for most ocean animals
• Greatest risk for deep-sea animals
• What we expect
• Ocean C storage will accelerate
• Ocean acidification will affect ocean
  ecosystems, especially in deep-sea. Effects
  will be mostly negative and could be very large
• What we dont know
• Thresholds in ocean carbon dioxide levels
  for catastrophic damage to ecosystems
• Impacts on ocean productivity marine food
  webs, fisheries

Multiple Stressors Synergistic effects of
warming, acidification, reduced oxygen levels may
further impact ocean ecosystems
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Is it hopeless, too late, too big.?

• Should we worry about climate change and the
  oceans?
• YES! Climate change affects the quality of
  our lives
• What can we do?
• Education
• Support energy efficiency non-carbon
  energy, reduced fossil fuel
  emissions
• Reconnect with nature
• Value the oceans
• Teach our children that our choices and
  actions are important
• Vote
• Consider the value of population control

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Ocean Life