the effect of ocean acidification on the shell sizes of ammonia beccarii

The effect of ocean The effect of ocean acidification on the shell sizes acidification on the shell sizes

of of Ammonia beccariiAmmonia beccariiValentin LazarValentin Lazar

Spring Valley High SchoolSpring Valley High School

Research ProblemResearch Problem• Carbon dioxide in the atmosphere is Carbon dioxide in the atmosphere is

increasing rapidly.increasing rapidly.• About half of the carbon dioxide gets About half of the carbon dioxide gets

absorbed by the oceans absorbed by the oceans (Doney, 2006). (Doney, 2006). • The oceans are absorbing too much The oceans are absorbing too much

carbon dioxide, and it is changing the carbon dioxide, and it is changing the pH of the oceans.pH of the oceans.

Diagram by Orr, J et al., 2005

Ocean acidificationOcean acidification• Ocean acidification is defined as the Ocean acidification is defined as the

process in which the pH of the process in which the pH of the oceans decrease.oceans decrease.

• This results from carbon dioxide This results from carbon dioxide entering the oceans.entering the oceans.

• The carbon dioxide is changing the The carbon dioxide is changing the chemistry of the oceans.chemistry of the oceans.

COCO22

COCO22 + H + H22OO HH22COCO33 HH++

HCOHCO33-1-1 COCO33

-2-2

Atmospheric Carbon DioxideAtmospheric Carbon Dioxide

Carbon DioxideCarbon Dioxide+ Water+ Water

Carbonic AcidCarbonic Acid Hydrogen IonsHydrogen Ions

Bicarbonate IonsBicarbonate Ions Carbonate IonsCarbonate Ions

Problems of ocean acidificationProblems of ocean acidification

• Some organisms use calcium Some organisms use calcium carbonate (CaCOcarbonate (CaCO33) for shells and ) for shells and exoskeletons exoskeletons (Doney, 2006).(Doney, 2006).

• Calcium carbonate can dissolve in Calcium carbonate can dissolve in low pH environments.low pH environments.

• Many of the organisms are important Many of the organisms are important food sources (ex. plankton, food sources (ex. plankton, foraminifers, corals)foraminifers, corals)

OceansOceans

• The pH of the oceans is normally in The pH of the oceans is normally in the range of 8.3 and 7.9 the range of 8.3 and 7.9 (Doney, (Doney, 2006).2006).

• The pH of the oceans varies with The pH of the oceans varies with location and depth.location and depth.

• This study will focus on both This study will focus on both extremes of the pH range, 8.3 and extremes of the pH range, 8.3 and 7.9.7.9.

Picture from http://www.royalsoc.ac.uk/displaypagedoc.asp?id=13539

Ammonia beccariiAmmonia beccarii

• Ammonia beccariiAmmonia beccarii are foraminifers are foraminifers that live in estuarine environments that live in estuarine environments and stay near the bottom of shallow and stay near the bottom of shallow waters near the coast. waters near the coast.

• Ammonia beccariiAmmonia beccarii eat algae and they eat algae and they reproduce asexually about every 30 reproduce asexually about every 30 days. days.

• They have shells made of calcium They have shells made of calcium carbonate about 300 carbonate about 300 μμm in diameter.m in diameter.

Photograph taken by Valentin Lazar

Chambers

Photograph taken by Valentin Lazar

Why Why Ammonia beccariiAmmonia beccarii??

• They consist of calcium carbonateThey consist of calcium carbonate• They were readily available.They were readily available.• They are easy to manage and They are easy to manage and

measure. measure. • It is better to test live organisms It is better to test live organisms

because it is a real-world scenario.because it is a real-world scenario.

Previous ResearchPrevious Research

• Coral was placed at pH of 8 and 7.2, and Coral was placed at pH of 8 and 7.2, and calcification was reduced calcification was reduced (Marubini & (Marubini & Atkinson, 1999).Atkinson, 1999).

• Coral was grown in ocean water with Coral was grown in ocean water with increased COincreased CO22 pressure, and calcification pressure, and calcification was reduced (Leclercq, Gattuso & Jaubert, was reduced (Leclercq, Gattuso & Jaubert, 2002).2002).

• E. huxleyiE. huxleyi was grown in seawater with was grown in seawater with different COdifferent CO22 concentrations and concentrations and deformations were visible. (Riebesell et deformations were visible. (Riebesell et al., 2000).al., 2000).

Pictures taken by Riebesell et al., 2000

PurposePurpose

• To identify whether ocean To identify whether ocean acidification has a significant effect on acidification has a significant effect on marine organisms at the oceans’ marine organisms at the oceans’ current pH range. (8.3-7.9)current pH range. (8.3-7.9)

• To provide insight as to how serious To provide insight as to how serious ocean acidification is to marine ocean acidification is to marine organisms that use calcium organisms that use calcium carbonate.carbonate.

HypothesisHypothesis

• As the pH of the water decreases, the As the pH of the water decreases, the shell sizes of the shell sizes of the Ammonia beccariiAmmonia beccarii will also decrease.will also decrease.

MaterialsMaterials

• Ammonia beccariiAmmonia beccarii• Instant OceanInstant Ocean• LabPro pH probeLabPro pH probe• LoggerProLoggerPro• Motic Images 1.2Motic Images 1.2• AlgaeAlgae• HydrometerHydrometer• Reef BufferReef Buffer

• Motic MicroscopeMotic Microscope• Petri dishesPetri dishes• MudMud• PipettesPipettes• Air PumpsAir Pumps• Minitab 14Minitab 14• StrawsStraws• 7 and 9 pH buffers7 and 9 pH buffers

Experimental Design DiagramExperimental Design Diagram

IV: The pH of the seawaterIV: The pH of the seawater8.3 (control)8.3 (control) 7.97.9

2323 2323DV: The diameters of the DV: The diameters of the A. beccariiA. beccarii shells (shells (μμmm))C: Magnification when measuring, salinity, C: Magnification when measuring, salinity, calibration method of pH probe, food given to each calibration method of pH probe, food given to each group amount of seawater in each dish/container. group amount of seawater in each dish/container.

MethodsMethods

Make seawaterMake seawater

Mix with mudMix with mud

Adjust pH and salinityAdjust pH and salinity

Grow Grow Ammonia beccariiAmmonia beccarii

Separate into two groupsSeparate into two groups

Two-sample t-testTwo-sample t-test

15-day pH treatment15-day pH treatment

Measure shell sizesMeasure shell sizes

Two-sample t-testTwo-sample t-test

Measure shell sizesMeasure shell sizes

Pictures taken by Valentin Lazar

VariableVariable 8.3-pH (um)8.3-pH (um) 7.9-pH (um)7.9-pH (um)MeanMean 242.72242.72 243.56243.56StDevStDev 44.7344.73 44.8844.88VarianceVariance 2001.162001.16 2014.442014.44MinimumMinimum 158.40158.40 172.10172.10MaximumMaximum 308.90308.90 323.60323.60RangeRange 150.50150.50 151.50151.50

Initial Descriptive StatisticsInitial Descriptive Statistics

Treatment

Shel

l Size

(um

)

7.9-pH Dish8.3-pH Dish

325

300

275

250

225

200

175

150

Dishes Before Experimentation


Experimental Descriptive StatisticsExperimental Descriptive Statistics

Treatment

Shel

l Size

(um

)

7.9-pH Dish8.3-pH Dish

340

320

300

280

260

240

220

200

180

Dishes After Experimentation

t-testt-test 3.293.29p-valuep-value .002.002Critical ValueCritical Value 1.961.96Degrees of FreedomDegrees of Freedom 4343The two samples are from different populations.The two samples are from different populations.

t-testt-test .06.06p-valuep-value .950.950Critical ValueCritical Value 1.961.96Degrees of FreedomDegrees of Freedom 4343The two samples are from the same population. The two samples are from the same population.

Initial two-sample t-testInitial two-sample t-test

Experimental two-sample t-testExperimental two-sample t-test

DiscussionDiscussion• The hypothesis was accepted.The hypothesis was accepted.• There is a significant difference There is a significant difference

between the 8.3-pH dish and the 7.9-between the 8.3-pH dish and the 7.9-pH dish.pH dish.

• Ammonia beccariiAmmonia beccarii are at risk from are at risk from ocean acidification today, at 7.9-pH.ocean acidification today, at 7.9-pH.

• The mean 7.9-pH shell size in the The mean 7.9-pH shell size in the experiment was less than the initial experiment was less than the initial mean.mean.


Initial Descriptive StatisticsInitial Descriptive Statistics


Experimental Descriptive StatisticsExperimental Descriptive Statistics

Sources of UncertaintySources of Uncertainty

• Conditions may not have simulated Conditions may not have simulated Ammonia beccariiAmmonia beccarii habitat. habitat.

• Did not specifically control pressure, Did not specifically control pressure, temperature, and luminosity.temperature, and luminosity.

• The pH or salinity may have been The pH or salinity may have been altered in the small petri dishes after altered in the small petri dishes after a certain period of time.a certain period of time.

Future ResearchFuture Research

• There need to be more studies on the There need to be more studies on the effects of ocean acidification on other effects of ocean acidification on other marine organism that are of more marine organism that are of more importance to ocean ecosystems.importance to ocean ecosystems.

• Long-term studies on ocean acidification in Long-term studies on ocean acidification in ocean ecosystems.ocean ecosystems.

• A way of dealing with ocean acidification A way of dealing with ocean acidification before it gets any worse is also important.before it gets any worse is also important.

AcknowledgementsAcknowledgements

• Dr. Chris Hintz from USC for providing me Dr. Chris Hintz from USC for providing me with with Ammonia beccariiAmmonia beccarii and giving and giving suggestions for better improving the suggestions for better improving the methodology.methodology.

• My teachers from Spring Valley High My teachers from Spring Valley High School.School.

• My parents for their encouragement and My parents for their encouragement and guidance.guidance.

Literature CitedLiterature Cited

• Doney, S. C. (2006, March). The dangers of ocean Doney, S. C. (2006, March). The dangers of ocean acidification. acidification. Scientific American, 294Scientific American, 294(3), 58-65.(3), 58-65.

• Leclercq, N., Gattuso, J.P., & Jaubert, J. (2002). Primary Leclercq, N., Gattuso, J.P., & Jaubert, J. (2002). Primary production, respiration, and calcification of a coral production, respiration, and calcification of a coral reef mesocosm under increased CO2 partial reef mesocosm under increased CO2 partial

pressure [Electronic version]. pressure [Electronic version]. Limnology and Limnology and Oceanography, 47,Oceanography, 47, 558-564. 558-564.

• Marubini, F., & Atkinson, M.J. (1999). Effects of lowered Marubini, F., & Atkinson, M.J. (1999). Effects of lowered pH and elevated nitrate on coral calcification. pH and elevated nitrate on coral calcification.

Marine Marine Ecology Progress Series, 188,Ecology Progress Series, 188, 117-121. 117-121.• Riebesell, U. et al. (2000, September 21). Reduced Riebesell, U. et al. (2000, September 21). Reduced

calcification of marine plankton in response to calcification of marine plankton in response to increased increased atmospheric COatmospheric CO22 [Electronic version]. [Electronic version]. Nature, 407Nature, 407, , 364-367. 364-367.

The effect of ocean The effect of ocean acidification on the shell sizes acidification on the shell sizes

of of Ammonia beccariiAmmonia beccariiValentin LazarValentin Lazar

Spring Valley High SchoolSpring Valley High School

the effect of ocean acidification on the shell sizes of ammonia beccarii

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