General Scheme for Working Group Objectives

Physiological/Biogeochemical ResponsesOrganisms and Communities

Ecosystem EffectsHow would changes in populations of calcifying

organisms affect ecosystems?

Exp

erim

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l man

ipu

lati

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Organism EffectsHow would the response affect species?

Earth System FunctioningCarbon cycle, CO2 uptake, feedbacks

Mo

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Pal

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Mo

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majority of studies

Pressing Questions Session 1Ecophysiological Responses of Calcifiers to Increased

pCO2 - Current Knowledge and Pressing QuestionsControls on calcification (only briefly review these if necessary)

Taxonomic differencesTechnological considerationsStandardization of measurements

Controls on calcification (only briefly review these if necessary)

Taxonomic differencesTechnological considerationsStandardization of measurements

What is evidence that CO2 chemistry controls calcification in nature?

Is calcification response to CO32– linear, or asymptotic?

What are the relative roles of HCO3– and CO3

2– in the calcification process?

What is the relationship between photosynthesis and calcification?

What is the impact of temperature/light/nutrients on calcification?

Pressing Questions Session 1Ecophysiological Responses of Calcifiers to Increased

pCO2- Current Knowledge and Pressing Questions

Controls on calcification

Taxonomic differences

Technological considerationsStandardization of measurements

• Do we need experimental data from more species, or across more groups?

• Can we expect calcifiers to adapt to rising pCO2 and if so, by what mechanisms? Over what time scales?

Pressing Questions Session 1Ecophysiological Responses of Calcifiers to Increased

pCO2- Current Knowledge and Pressing Questions

Controls on calcification

Taxonomic differencesTechnological considerations

Standardization of measurements

• What are the technological capabilities and challenges for CO2 system measurements and calcification measurements?

• What questions are best addressed in field studies, lab studies, or mesocosms?

• What questions can be addressed through modeling? • What important ecophysiological parameters are not currently

included in models because of lack of data?

Pressing Questions Session 1Ecophysiological Responses of Calcifiers to Increased

pCO2- Current Knowledge and Pressing Questions

• What are the advantages/disadvantages of existing research designs, sampling, manipulation of CO2 chemistry, etc?

• Can we recommend “standards” within this arena? • How can different measures of calcification be

related/standardized?

Controls on calcification

Taxonomic differencesTechnological considerationsStandardization of measurements

Pressing Questions Session 1Ecophysiological Responses of Calcifiers to Increased

pCO2- Current Knowledge and Pressing Questions

Pressing Questions Session 2Ecosystem Response to Elevated pCO2: Existing and Future Filed Monitoring and

Experimental Research

Ecological responses

Regional considerations

Ecological responses

Regional considerations

• Will calcifying organisms be outcompeted by noncalcifiers? If so, What impacts to ecosystem structure and function might occur?

• What changes, if any, may occur in food webs and other species interactions?

• How could such ecological responses affect the cycling of organic and inorganic C?

Pressing Questions Session 2Ecosystem Response to Elevated pCO2: Existing and Future Field Monitoring and

Experimental Research

• What information can be obtained by conducting studies in regions with natural variability in pCO2?

• What regions would be most promising in terms of better characterizing CO2-chemistry environment?

• Which regions do models indicate will likely experience the greatest changes in seawater carbonate chemistry?

• Over what time scales?

Ecological responses

Regional considerations

Pressing Questions Session 2Ecosystem Response to Elevated pCO2: Existing and Future Field Monitoring and

Experimental Research

Pressing Questions Session 3

• What experimental designs are needed to address the pressing questions?

• What can be done now, with existing technology (both pelagic and neritic regions)?

• What can be done within next 5-10 years, with emerging technology? • What are the coastal needs/concerns, versus those of open ocean

(e.g., precision, contamination, etc.)? • Can we capitalize on existing monitoring/research efforts to obtain

more/better data? where? how? • How can we measure dissolution within the water column and within

sediments? What is the role of dissolution in buffering the system?• How can we focus paleoclimatology, isotopic analyses, etc. to

address questions about CO2 affects on calcification?

• How can remote sensing be integrated into the overall monitoring and experimental designs? Are there pressing needs to develop new remote sensing technology?

Experimental Design

Pressing Questions Session 4

• What are the priorities in modeling the CO2-calcification questions? (carbon cycle? ecosystem/community interactions? physiological modeling? sediment/water interactions? etc.)?

• What important questions can be addressed with existing models?  Which will require model development?

• Which modeling questions would be well constrained versus poorly constrained by existing data?

Modeling

Ecology•Habit & domain•Response to nutrient, light, temperature changes•Biodiversity•Food webs & species interactions•Capacity to adapt to elevated pCO2

Calcification•Production cycle/generation times•Mineralogy•CaCO3 production and net accumulation

Carbonate System Behavior•pCO2 variability •Influence of sedimentary processes

Carbon Cycling•Role in the carbon cycle

Planktonic versus Benthic Calcifiers

Possible Functions of CaCO3 in OrganismsFunction Planktonic BenthicProtection All groups All groups

Buoyancy regulation coccolithophores foraminifera

Light modification coccolithophores corals

Provide protons for conversion of HCO3

– to CO2 for photosynth.coccolithophores calcareous algae?

Facilitate bicarbonate-based photosynthesis

coccolithophores

Aid in capture of prey foraminifera

Reproduction pteropods corals?

Prevention of osmotically induced volume changes

coccolithophores

Extension into hydrodynamic regime

corals, calc. algae, bryozoans

Anchoring to substrate corals, calc. algae, bryozoans

Competition for space corals, calc. algae, bryozoans

mm

Ecosystem Effects

experimentalmanipulations

Earth SystemCarbon Cycle

modeling

paleorecords

monitoring

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10–2

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Physiology

Organism

remote sensing