Effects of CO Effects of CO 2 2 on marine on marine animals animals Time scales, processes, and limits of Time scales, processes, and limits of adaptation adaptation Hans O. Pörtner, Martina Langenbuch, Basile Michaelidis Alfred-Wegener-Institute, Bremerhaven, Germany, Aristotle University of Thessaloniki, Greece. Interactions with temperature and hypoxia regimes Scenarios: • Business as usual, • Direct disposal, • Indirect disposal
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Effects of CO 2 on marine animals Time scales, processes, and limits of adaptation Hans O. Pörtner, Martina Langenbuch, Basile Michaelidis Alfred-Wegener-Institute,
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Effects of COEffects of CO22 on marine animals on marine animals Time scales, processes, and limits of adaptationTime scales, processes, and limits of adaptation
Hans O. Pörtner, Martina Langenbuch, Basile Michaelidis
Alfred-Wegener-Institute, Bremerhaven, Germany,
Aristotle University of Thessaloniki, Greece.
Interactions with temperature and hypoxia regimes
Scenarios: • Business as usual, • Direct disposal, • Indirect disposal
(Fe fertilization)
Principle considerations: Role of time scales in CO2 exposure experiments
Incipient lethalCO2 level
(long term critical threshold)
arbitraryunits
Mortality independent
of exposure time
Zone of resistanceMortality dependent on CO2 level and
exposure time
Zone of tolerance
Up
per
med
ian
leth
al C
O2 l
evel
(L
D50
)
log exposure time (days, weeks, months, years) →
No such complete data set exists
Tolerable organism and ecosystem (?) responses
critical level and mechanism unknown
†Asphyxiation: squid and fish
Pörtner, in prep.
Example of an Example of an animal species animal species tolerant to COtolerant to CO2 2
oscillations:oscillations:SSipunculusipunculus
nudusnudus
eurybathic: eurybathic: found between 0 and found between 0 and 2300 m depths2300 m depths
However, tolerance However, tolerance is limited: is limited:
Delayed onset of Delayed onset of enhanced mortality enhanced mortality
during long term during long term „disturbed“ „disturbed“
maintenance under 1 maintenance under 1 % CO% CO22 in in S. nudusS. nudus
0 50 100 150 200 250
0
20
40
60
80
100
120 ControlControl
1 % CO1 % CO2 2 earlyearly
1% CO1% CO2 2 latelate
3 % CO3 % CO22
% M
orta
lity
% M
orta
lity
Days of incubation
• no decrease in body energy stores
• behavioral incapacitation involved
Langenbuch et al. (2004)
Control animals repeatedly
reburying into sediment
Permian-Permian-Triassic Triassic
mass mass extinctionsextinctions
Loss of Loss of marine marine
invertebrate invertebrate generagenera
due to COdue to CO22??
moderately active,moderate calcification
sessile, hypometabolic, calcified: larger effect?
after Knoll et al., 1996
Physiological characters of eliminated forms?
severest losses
COCO22 limitations relevant in evolution? limitations relevant in evolution?
Number of genera
Time (h)
7,0
7,2
7,4
7,6
7,8
8,0
1 % CO2 pH
pl
-48 0 48 96 144
7,2
7,4
pHi
ControlS. nudusS. nudus::
Extra- and Extra- and intracellular intracellular
acid-base status acid-base status during during
hypercapniahypercapniain vivoin vivo
after Pörtner et al. 1998
partial compensation
full compensation Partial Partial compensation of compensation of
extracellular extracellular acidosis: acidosis:
A typical finding A typical finding in invertebrates?in invertebrates?
Uncompensated intracellular acidosis in Uncompensated intracellular acidosis in cuttlefish (cuttlefish (S. officinalisS. officinalis)) brainbrain under under
24 h of hypercapnia (1%) 24 h of hypercapnia (1%)
7.2
7.25
7.3
7.35
7.4
7.45
7.5
7.55
-3 1 5 9 13 17 21 25 29 33
time (h)
Hypercapnia Normocapnia* *
intr
acel
lula
r p
HSepia officinalisSepia officinalis
S. Schmidt, C. Bock, H.O. Pörtner, unpubl.
Animals died despite return to normocapnia!!!Animals died despite return to normocapnia!!!
Uncompensated acidosisUncompensated acidosisand metabolic depression in several invertebratesand metabolic depression in several invertebrates
…contributing to lower resistance and enhanced mortality?
Compensated acidosis Compensated acidosis and, therefore, no metabolic depression in most fishand, therefore, no metabolic depression in most fish
OO22 dependent temperature limits verified across phyla: dependent temperature limits verified across phyla:
annelids, sipunculids, molluscs (bivalves, cephalopods), annelids, sipunculids, molluscs (bivalves, cephalopods), crustaceans, fish and some air breathers, limited evidence in crustaceans, fish and some air breathers, limited evidence in
endotherms incl. man.endotherms incl. man.
0
% oxygen limitedaerobicscope
Tc
Tp Tp : Peius T‘s: onset of limitation in aerobic scope
after Frederich and Pörtner 2000, Mark et al. 2002Pörtner et al. 2000, Pörtner 2001, 2002
100
Cardiac +ventila-toryoutput
0
functional capacity of oxygen supply
Qrest•
Qmax•
after Farrell
max Aerobic scope and performance Aerobic scope and performance are maximal at the upper peius are maximal at the upper peius temperature.temperature.
rate of aerobicperfor-mance
0temperature
Hypoxia, COHypoxia, CO22 and thermal and thermal
extremes act synergistically extremes act synergistically via the same physiological via the same physiological mechanisms!!mechanisms!!
Hypoxia, COHypoxia, CO22
Hypoxia, COHypoxia, CO22
Processes and Limits:Processes and Limits: Effects of integrated CO Effects of integrated CO22, O, O22 and temperature fluctuations and temperature fluctuations
CO2 impacts on:
Hypoxia tolerance ↑→ Improved extension of passive survival (limited!)
BUT
Aerobic scope ↓→ Long term performance and growth functions ↓ → Thermal tolerance ↓
(tolerance to thermal fluctuations ↓)
These interactions and not COThese interactions and not CO2 2 alone have likely shaped alone have likely shaped
evolutionary scenarios!evolutionary scenarios!Pörtner and Langenbuch, in prep.
Animal limitations in high COAnimal limitations in high CO22 oceans oceansProgressive (not beyond critical thresholds?) effects already Progressive (not beyond critical thresholds?) effects already
expected in 450 to 750 ppm surface ecosystemsexpected in 450 to 750 ppm surface ecosystemsshifted ecosystem equilibrashifted ecosystem equilibra caused by: caused by:- reduced calcification ratesreduced calcification rates
- higher ratios of non-calcifiers over calcifiershigher ratios of non-calcifiers over calcifiers- reduced tolerance to thermal extremes reduced tolerance to thermal extremes
- enhanced geographical distribution shiftsenhanced geographical distribution shifts- reduced distribution rangesreduced distribution ranges
- reduced behavioral capacity, growth, productivity and life reduced behavioral capacity, growth, productivity and life spanspan**- food chain length and compositionfood chain length and composition**- reduced population densities, ……biodiversity (critical!)?reduced population densities, ……biodiversity (critical!)?**
*effects transferred to deep with ocean disposal (direct and indirect)Research needs to further identify mechanisms, titrate/quantify (lab and field) scenarios, address micro-evolutionary potential
Pörtner and Langenbuch, in prep.
Ocean COOcean CO22 disposal: disposal:
Are their methods of choice?Are their methods of choice? Preliminary insight from COPreliminary insight from CO22, T, hypoxia impact studies in animals, T, hypoxia impact studies in animals
• Avoid business as usual scenarios • (thermal changes, direct impact of CO2!)
• Avoid large scale disposal strategies • (towed pipe or Fe fertilization)
• If feasible, use CO2 lake option in environments protected from physical disturbance („dump site“ strategy)
• Apply direct pH neutralization of injected CO2?
• Dispose in thermally stable environments• Avoid hypoxia aggravation (eutrophication)
Pörtner and Langenbuch, in prep.
CLIMATE CHANGE, CO2 effects, ENERGY BUDGETS
Dr. Christian Bock Carsten BurkhardDr. Martina LangenbuchDr. Anke ReipschlägerSusannSchmidt Rolf-M. Wittig