Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Rising CO2 and increased light exposure synergistically reduce marine primary productivity


Carbon dioxide and light are two major prerequisites of photosynthesis. Rising CO2 levels in oceanic surface waters in combination with ample light supply are therefore often considered stimulatory to marine primary production1,2,3. Here we show that the combination of an increase in both CO2 and light exposure negatively impacts photosynthesis and growth of marine primary producers. When exposed to CO2 concentrations projected for the end of this century4, natural phytoplankton assemblages of the South China Sea responded with decreased primary production and increased light stress at light intensities representative of the upper surface layer. The phytoplankton community shifted away from diatoms, the dominant phytoplankton group during our field campaigns. To examine the underlying mechanisms of the observed responses, we grew diatoms at different CO2 concentrations and under varying levels (5–100%) of solar radiation experienced by the phytoplankton at different depths of the euphotic zone. Above 22–36% of incident surface irradiance, growth rates in the high-CO2-grown cells were inversely related to light levels and exhibited reduced thresholds at which light becomes inhibitory. Future shoaling of upper-mixed-layer depths will expose phytoplankton to increased mean light intensities5. In combination with rising CO2 levels, this may cause a widespread decline in marine primary production and a community shift away from diatoms, the main algal group that supports higher trophic levels and carbon export in the ocean.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Primary production in CO2-perturbed microcosms by phytoplankton assemblages collected in the SCS and East China Sea (station PN07).
Figure 2: Growth rates of cultured diatoms as a function of pCO2 and light.
Figure 3: High- to low-pCO2 ratios for growth rates and photosynthetic parameters in cultured diatoms.


  1. Schippers, P., Lürling, M. & Scheffer, M. Increase of atmospheric CO2 promotes phytoplankton productivity. Ecol. Lett. 7, 446–451 (2004).

    Article  Google Scholar 

  2. Riebesell, U. & Tortell, P. D. in Effects of Ocean Acidification on Pelagic Organisms and Ecosystems in Ocean Acidification (eds Gattuso, J. P. & Hansson, L.) 291–311 (Oxford Univ. Press, 2011).

    Google Scholar 

  3. Hein, M. & Sand-Jensen, K. CO2 increases oceanic primary production. Nature 388, 526–527 (1997).

    Article  CAS  Google Scholar 

  4. IPCC Climate Change 2001: The Scientific Basis (eds Houghton, J. T. et. al) (Cambridge Univ. Press, 2001).

  5. Boyd, P. W., Strzepek, R., Fu, F. & Hutchins, D. A. Environmental control of open-ocean phytoplankton groups: Now and in the future. Limnol. Oceanogr. 55, 1353–1376 (2010).

    Article  CAS  Google Scholar 

  6. Sabine, C. L. et al. The oceanic sink for anthropogenic CO2 . Science 305, 367–371 (2004).

    Article  CAS  Google Scholar 

  7. Caldeira, K. & Wickett, M. E. Oceanography: Anthropogenic carbon and ocean pH. Nature 425, 365 (2003).

    Article  CAS  Google Scholar 

  8. Feely, R. A. et al. Impact of anthropogenic CO2 on the CaCO3 system in the oceans. Science 305, 362–366 (2004).

    Article  CAS  Google Scholar 

  9. Riebesell, U. et al. Reduced calcification of marine plankton in response to increased atmospheric CO2 . Nature 407, 364–367 (2000).

    Article  CAS  Google Scholar 

  10. Beaufort, L. et al. Sensitivity of coccolithophores to carbonate chemistry and ocean acidification. Nature 476, 80–83 (2011).

    Article  CAS  Google Scholar 

  11. Gao, K. S. & Zheng, Y. Q. Combined effects of ocean acidification and solar ultraviolet radiation on photosynthesis, growth, pigmentation and calcification of the coralline alga Corallina sessilis (Rhodophyta). Glob. Change Biol. 16, 2388–2398 (2010).

    Article  Google Scholar 

  12. Fine, M. & Tchernov, D. Scleractinian coral species survive and recover from decalcification. Science 315, 1811 (2007).

    Article  CAS  Google Scholar 

  13. Hutchins, D. et al. CO2 control of Trichodesmium N2 fixation, photosynthesis, growth rates, and elemental ratios: Implications for past, present, and future ocean biogeochemistry. Limnol. Oceanogr. 52, 1293–1304 (2007).

    Article  CAS  Google Scholar 

  14. Tortell, P. D., Rau, G. H. & Morel, F. M. M. Inorganic carbon acquisition in coastal Pacific phytoplankton communities. Limnol. Oceanogr. 45, 1485–1500 (2000).

    Article  CAS  Google Scholar 

  15. Riebesell, U. et al. Enhanced biological carbon consumption in a high CO2 ocean. Nature 450, 545–548 (2007).

    Article  CAS  Google Scholar 

  16. Hutchins, D. A., Mulholland, M. R. & Fu, F. Nutrient cycles and marine microbes in a CO2-enriched ocean. Oceanography 22, 128–145 (2009).

    Article  Google Scholar 

  17. Behrenfeld, M. J. et al. Climate-driven trends in contemporary ocean productivity. Nature 444, 752–755 (2006).

    Article  CAS  Google Scholar 

  18. Boyce, D. G., Lewis, M. R. & Worm, B. Global phytoplankton decline over the past century. Nature 466, 591–596 (2010).

    Article  CAS  Google Scholar 

  19. Boyd, P. W. Beyond ocean acidification. Nature Geosci. 4, 273–274 (2011).

    Article  CAS  Google Scholar 

  20. Nelson, D. M., Tréguer, P., Brzezinski, M. A., Leynaert, A. & Quéguiner, B. Production and dissolution of biogenic silica in the ocean: Revised global estimates, comparison with regional data and relationship to biogenic sedimentation. Glob. Biogeochem. Cycles 9, 359–359 (1995).

    Article  CAS  Google Scholar 

  21. Wu, H., Cockshutt, A. M., McCarthy, A. & Campbell, D. A. Distinctive PSII photoinactivation and protein dynamics in marine diatoms. Plant Physiol. 156, 2184–2195 (2011).

    Article  CAS  Google Scholar 

  22. Wu, Y., Gao, K. & Riebesell, U. CO2-induced seawater acidification affects physiological performance of the marine diatom Phaeodactylum tricornutum. Biogeosciences 7, 2915–2923 (2010).

    Article  CAS  Google Scholar 

  23. Hopkinson, B. M., Dupont, C. L., Allen, A. E. & Morel, F. M. M. Efficiency of the CO2-concentrating mechanism of diatoms. Proc. Natl Acad. Sci. USA 108, 3830–3837 (2011).

    Article  CAS  Google Scholar 

  24. Raven, J. A., Giordano, M., Beardall, J. & Maberly, S. C. Algal and aquatic plant carbon concentrating mechanisms in relation to environmental change. Photosynth. Res. 109, 281–296 (2011).

    Article  CAS  Google Scholar 

  25. Chen, X. & Gao, K. Characterization of diurnal photosynthetic rhythms in the marine diatom Skeletonema costatum grown in synchronous culture under ambient and elevated CO2 . Funct. Plant Biol. 31, 399–404 (2004).

    Article  CAS  Google Scholar 

  26. Rost, B., Riebesell, U., Burkhardt, S. & Sueltemeyer, D. Carbon acquisition of bloom-forming marine phytoplankton. Limnol. Oceanogr. 48, 55–67 (2003).

    Article  Google Scholar 

  27. Wingler, A., Lea, P. J., Quick, W. P. & Leegood, R. C. Photorespiration: Metabolic pathways and their role in stress protection. Phil. Trans. R. Soc. Lond. B. 355, 1517–1529 (2000).

    Article  CAS  Google Scholar 

  28. Boyd, P. W. & Doney, S. C. Modelling regional responses by marine pelagic ecosystems to global climate change. Geophys. Res. Lett. 29, 1806 (2002).

    Google Scholar 

  29. Gao, K. S., Ruan, Z. X., Villafane, V. E., Gattuso, J. P. & Helbling, E. W. Ocean acidification exacerbates the effect of ultraviolet radiation on the calcifying phytoplankter Emiliania huxleyi. Limnol. Oceanogr. 54, 1855–1862 (2009).

    Article  CAS  Google Scholar 

  30. Chen, S. & Gao, K. Solar ultraviolet radiation and CO2-induced ocean acidification interacts to influence the photosynthetic performance of the red tide alga Phaeocystis globosa (Prymnesiophyceae). Hydrobiologia 675, 105–117 (2011).

    Article  CAS  Google Scholar 

  31. Gao, K. et al. Solar ultraviolet radiation drives CO2 fixation in marine phytoplankton: A double-edged sword. Plant Physiol. 144, 54–59 (2007).

    Article  CAS  Google Scholar 

  32. Genty, B., Briantais, J. M. & Baker, N. R. The relationship between the quantum yield of photosynthetic electron-transport and quenching of chlorophyll fluorescence. Biochim. Biophys. Acta 990, 87–92 (1989).

    Article  CAS  Google Scholar 

  33. Morel, F. M. M., Rueter, J. G., Anderson, D. M. & Guillard, R. R. L. Aquil: A chemically defined phytoplankton culture medium for trace metal studies. J. Phycol. 15, 135–141 (1979).

    Article  CAS  Google Scholar 

  34. Guillard, R. R. & Ryther, J. H. Studies of marine planktonic diatoms. I. Cyclotella nana Hustedt, and Detonula confervacea (cleve) Gran. Can. J. Microbiol. 8, 229–239 (1962).

    Article  CAS  Google Scholar 

Download references


We thank the expedition chief scientists M. Dai, P. Cai and W. Zhai and the crew from Dong-Fang-Hong for their support and help during the cruises. The cruise and laboratory studies were supported by the National Basic Research Program of China (2009CB421207, 2011CB200902) and by the National Natural Science Foundation of China (no. 41120164007 and no. 40930846). The Changjiang Scholars and Innovative Research Team project (IRT0941) and China–Japan collaboration project from the Ministry of Science and Technology (S2012GR0290) are also acknowledged for the field work. D.A.H’s contribution was supported by the United States National Science Foundation Division of Ocean Sciences grants 0942379, 0962309 and 1043748. U.R. acknowledges support by the German Ministry of Education and Research through the project BIOACID. Visits of D.A.H. and U.R. to Xiamen were supported by the 111 project and by the State Key Laboratory of Marine Environmental Science (Xiamen University). The visit of K.G. to Kiel was supported by the German Academic Exchange Service (DAAD).

Author information

Authors and Affiliations



On the basis of an original idea from K.G., the concept of this paper was developed in discussion between all authors. J.X. and G.G. contributed as equally as K.G. for their leading roles in laboratory and field experiments, respectively. U.R. and D.A.H. contributed to experimental designs, data analysis and the writing of the paper. D-P.H. contributed to the analysis of the data and writing of the paper. G.G., Y.Z., P.J., K.X., B.H., L.W. and N.L. carried out shipboard experiments; J.X., Y.L., X.C. and W.L. carried out laboratory experiments.

Corresponding author

Correspondence to Kunshan Gao.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Gao, K., Xu, J., Gao, G. et al. Rising CO2 and increased light exposure synergistically reduce marine primary productivity. Nature Clim Change 2, 519–523 (2012).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing