Coral Growth in Response to Increased Atmospheric CO 2

1. Coral Growth in Response to Increased Atmospheric CO2 Jim Billingsley Biology 881 University of Nebraska, Kearney

2. Introduction • Overview • Coral Structure • Seawater Chemistry • Affects of CO2 on Seawater • Conclusions

3. Overview • CO2 emissions • Physiology of marine organisms. • CO2 • CO32-

4. Overview Photosynthesis and calcification problems • Sealevel rise • Faster growing algae • Boring organisms and storm damage

5. Trends in Atmospheric CO2 Vostok, Antarctica Ice Core Atmospheric CO2 Record Mauna Loa, Hawaii and Law Dome, Antarctica (Petit, et al, 1999) (Etheridge et al, 1998); (Keeling and Whorf, 2001)

6. Global Emission of CO2 (Marland, Boden and Andres 2001)

7. Coral Structure • Polyps • Colony • Nematocysts

8. Coral Structure • Animal • Calcium carbonate skeleton • Symbiotic plant

9. Zooxanthellae • Dinoflaggellate • Photosynthetic • Pigments

10. Seawater Chemistry H2O + CO2 (aq)  H2CO3HCO3- + H+

11. Dissolution of calcium carbonate • Temperature, pressure and partial pressure of carbon dioxide • CaCO3 + H20 + CO2 Ca2+ + 2HCO3- • Higher pressures and cooler temperatures • Corrosive

12. CO2 Emissions and Calcification in the Oceans 1880 • Rising atmospheric CO2 • Carbonate equilibrium • Decrease in alkalinity • Reduces the CaCO3 saturation • Harder for coral reefs to grow Present Future – Double CO2

13. Calculated changes seawater carbonate chemistry(assuming S=35, TA=3.5 meq/L) Warag CO2 aq

14. Observations at the Hawaii Ocean Times Series Station

15. Chemical treatments

16. Effect of CO2 on community calcification

17. Coral Response Porites compressa 200 matm 700 matm (Marubini et al., 2001)

18. Effect of a doubling in CO2 (350-700) on calcification, (% decrease) Calcareous macroalgae Amphiroa foliacea -36 Borowitzka, 1981 Porolithon gardineri -16 Agegian, 1985 Corallina pilulifera -44 Gao et al., 1993 Corals Stylophora pistillata -3 Gattuso et al., 1998 Porites porites -16 Marubini & Thake, 1999 Porites compressa -27 Marubini et al., 2001 Acropora sp. -37 Schneider & Erez, 2000 Porites/Montipora -50Langdon & Atkinson, in prep. Coccolithophorids Emiliania huxleyi -10 Riebesell et al., 2000 Gephyrocapsa oceanica -29 “ “ Natural pop. (N. Pac.) -38 “ “ Emiliania huxleyi -17 Zondervan et al., 2001 Gephyrocapsa oceanica –29 “ “ Community Biosphere 2 -40 Langdon et al., 2000 Monaco mesocosm -21 Leclercq et al., 2000 Bahama Bank -30 Broecker & Takahashi, 1966

19. Future pH Changes • Burn all known stocks of fossil fuels • Atmospheric CO2 would exceed 1,900 parts per million around the year 2300 • pH reduction at the ocean surface • Calcium carbonate skeletons • Unabated CO2 emissions • Changes in ocean pH

20. Conclusions • CO2 Calcification • for 200 to 280 matm pCO2 Calcif. 34% • for 350 to 700 matm pCO2 Calcif. 58%

21. Conclusions • Saturation state (W) controls calcification • Consequences of reduced calcification • Space and light • Sealevel rise • Erosion and damage • Decomposition of Calcium Carbonate

22. Literature Cited • Barker, S., Higgins, J.A., and Elderfield, H. 2003. The future of the carbon cycle: review,calcification response, ballast and feedback on atmospheric CO2. Philosophical Transaction of the Royal Society, 361, 1977–1999. • Caldeira, K. and Wickett, M.E. 2003 Oceanography: anthropogenic carbon and ocean pH. Nature, 425, 365. • Etheridge, D.M., ,Steele, L.P., R.L. Langenfelds, Francey, R.J., Barnola, J.M., and Morgan, V.I.. 1998. Historical CO2 records from the Law Dome DE08, DE08-2, and DSS ice cores. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. • Gattuso, J.-P., Allemand, D., and Frankigoulle, M. 1999. Photosynthesis and Calcification at Cellular, Organismal and Community Levels in Coral Reefs: A Review on Interactions and Control by Carbonate Chemistry. American Zoological Society, 39, 160-183. • Gerin, F. & Edmunds, B. 2001. Mechanisms of interaction between macroalgae and scleractinians on a coral reef in Jamaica. Journal of Experimental Marine Biology and Ecology, 261, 159–172.

23. Literature Cited • Keeling, C.D. and Whorf, T.P. 2005. Atmospheric CO2 records from sites in the SIO air sampling network. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. • Langdon, C. 2001. Overview of experimental evidence for effects of CO2 on calcification of reef builders. Proceedings of the 9th International Coral Reef Symposium, Oct 23.27, 2000, Bali Indonesia. • Marland, G., Boden, T.A., and Andres, R.J. 2006. Global, Regional, and National Fossil Fuel CO2 Emissions. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. • Marubini, H., Barnett, C., Langdon, M., and Atkinson, M.J. 2001. Dependence of calcification on light and carbonate ion concentration for the hermatypic coralPorites compressa. Marine Ecology Progress Series, 220, 153–162. • Marubini, F., Ferrier-Pages, C., and Cuif, J.-P. 2003. Suppression of skeletal growth in scleractinian corals by decreasing ambient carbonate-ion concentration: a cross-family comparison. Proceedings of the Royal Society of London B, 270, 179–184. • Petit, R., Jouzel, J., and Raynaud, D. 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429-436.