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.

Interactive effects of ozone depletion and vertical mixing on photosynthesis of Antarctic phytoplankton


Photosynthesis of Antarctic phytoplankton is inhibited by ambient ultraviolet (UV) radiation during incubations1,2,3,4, and the inhibition is worse in regions beneath the Antarctic ozone ‘hole’4. But to evaluate such effects, experimental results on, and existing models of, photosynthesis5,6,7 cannot be extrapolated directly to the conditions of the open waters of the Antarctic because vertical mixing of phytoplankton alters UV exposure and has significant effects on the integrated inhibition through the water column2,8,9. Here we present a model of UV-influenced photosynthesis in the presence of vertical mixing, which we constrain with comprehensive measurements from the Weddell-Scotia Confluence during the austral spring of 1993. Our calculations of photosynthesis integrated through the water column (denoted PT) show that photosynthesis is strongly inhibited by near-surface UV radiation. This inhibition can be either enhanced or decreased by vertical mixing, depending on the depth of the mixed layer. Predicted inhibition is most severe when mixing is rapid, extending to the lower part of the photic zone. Our analysis reveals that an abrupt 50% reduction in stratospheric ozone could, in the worst case, lower PT by as much as 8.5%. However, stronger influences on inhibition can come from realistic changes in vertical mixing (maximum effect on PT of about ±37%), measured differences in the sensitivity of phytoplankton to UV radiation (±46%) and cloudiness (±15%).

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout

Figure 1: Models of photoinhibition during vertical mixing.
Figure 2: Model results constrained by direct measurements from the WSC9.


  1. Lubin, al. Acontribution toward understanding the biospherical significance of Antarctic ozone depletion. J. Geophys. Res. 97, 7817–7828 (1992).

    Article  ADS  CAS  Google Scholar 

  2. Helbling, E. W., Villafañe, V. & Holm-Hansen, O. in Ultraviolet Radiation in Antarctica: Measurements and Biological Effects(eds Weiler, C. S. & Penhale, P. A.) 207–227 (Am. Geophys. Union, Washington DC, (1994).

    Book  Google Scholar 

  3. Vernet, M., Brody, E. A., Holm-Hansen, O. & Mitchell, B. G. in Ultraviolet Radiation in Antarctica: Measurements and Biological Effects(eds Weiler, C. S. & Penhale, P. A.) 143–158 (Am. Geophys. Union, Washington DC, (1994).

    Book  Google Scholar 

  4. Smith, R. al. Ozone depletion: Ultraviolet radiation and phytoplankton biology in Antarctic waters. Science 255, 952–959 (1992).

    Article  ADS  CAS  Google Scholar 

  5. Neale, P. J., Lesser, M. P. & Cullen, J. J. in Ultraviolet Radiation in Antarctica: Measurements and Biological Effects(eds Weiler, C. S. & Penhale, P. A.) 125–142 (Am. Geophys. Union, Washington DC, (1994).

    Book  Google Scholar 

  6. Arrigo, K. R. Impact of ozone depletion on phytoplankton growth in the Southern Ocean: large-scale spatial and temporal variability. Mar. Ecol. Prog. Ser. 114, 1–12 (1994).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  7. Boucher, N. & Prézelin, B. B. An in situ biological weighting function for UV inhibition of phytoplankton carbon fixation in the Southern Ocean. Mar. Ecol. Prog. Ser. 144, 223–236 (1996).

    Article  ADS  Google Scholar 

  8. Smith, R. C. & Baker, K. S. in The Role of Solar Ultraviolet Radiation in Marine Ecosystems(ed. Calkins, J.) 509–537 (Plenum, New York, (1982).

    Book  Google Scholar 

  9. Neale, P. J., Cullen, J. J. & Davis, R. F. Inhibition of marine photosynthesis by ultraviolet radiation: Variable sensitivity of phytoplankton in the Weddell-Scotia Confluence during the austral spring. Limnol. Oceanogr.(in the press).

  10. Behrenfeld, M. J., Chapman, J. W., Hardy, J. T. & Lee, H. I Is there a common response to ultraviolet-b radiation by marine phytoplankton. Mar. Ecol. Prog. Ser. 102, 59–68 (1993).

    Article  ADS  Google Scholar 

  11. Cullen, J. J., Neale, P. J. & Lesser, M. P. Biological weighting function for the inhibition of phytoplankton photosynthesis by ultraviolet radiation. Science 258, 646–650 (1992).

    Article  ADS  CAS  Google Scholar 

  12. Boucher, N. P. & Prézelin, B. B. Spectral modeling of UV inhibition of in situ Antarctic primary production using a field derived biological weighting function. Photochem. Photobiol. 64, 407–418 (1996).

    Article  CAS  Google Scholar 

  13. Veth, C. The evolution of the upper water layer in the marginal ice zone, austral spring 1988, Scotia-Weddell Sea. J. Mar. Syst. 2, 451–464 (1991).

    Article  ADS  Google Scholar 

  14. Nelson, D. M. & Smith, W. O. J Sverdrup revisited: Critical depths, maximum chlorophyll levels, and the control of Southern Ocean productivity by the irradiance-mixing regime. Limnol. Oceanogr. 36, 1650–1661 (1991).

    Article  ADS  Google Scholar 

  15. Cullen, J. J. & Lesser, M. P. Inhibition of photosynthesis by ultraviolet radiation as a function of dose and dosage rate: Results for a marine diatom. Mar. Biol. 111, 183–190 (1991).

    Article  Google Scholar 

  16. Franks, P. J. S. & Marra, J. Asimple new formulation for phytoplankton photoresponse and an application in a wind-driven mixed-layer model. Mar. Ecol. Prog. Ser. 111, 145–153 (1994).

    Article  ADS  Google Scholar 

  17. Yamazaki, H. & Kamykowski, D. The vertical trajectories of motile phytoplankton in a wind-mixed water column. Deep-Sea Res. 38, 219–241 (1991).

    Article  ADS  Google Scholar 

  18. Anis, A. & Moum, J. N. Surface wave-turbulence interactions: scaling ε(z) near the sea surface. J. Phys. Oceanogr. 25, 2025–2045 (1995).

    Article  ADS  Google Scholar 

  19. Prézelin, B. B., Boucher, N. P. & Smith, R. C. in Ultraviolet Radiation in Antarctica: Measurements and Biological Effects(eds Weiler, C. S. & Penhale, P. A.) 159–186 (Am. Geophys. Union, Washington DC, (1994).

    Book  Google Scholar 

  20. Helbling, E. W., Villafañe, V., Ferrario, M. & Holm-Hansen, O. Impact of natural ultraviolet radiation on rates of photosynthesis and on specific marine phytoplankton species. Mar. Ecol. Prog. Ser. 80, 89–100 (1992).

    Article  ADS  Google Scholar 

  21. Zepp, R. G. & Cline, D. M. Rates of direct photolysis in aquatic environment. Environ. Sci. Technol. 11, 359–366 (1977).

    Article  ADS  CAS  Google Scholar 

  22. Murray, A. G. & Jackson, G. A. Viral dynamics II: a model of the interaction of ultraviolet light and mixing processes on virus survival in seawater. Mar. Ecol. Prog. Ser. 102, 105–114 (1993).

    Article  ADS  Google Scholar 

  23. Vincent, W. F. & Roy, S. Solar ultraviolet-B radiation and aquatic primary production: damage, protection and recovery. Environ. Rev. 1, 1–12 (1993).

    Article  CAS  Google Scholar 

  24. Morel, A. Available, usable, and stored radiant energy in relation to marine photosynthesis. Deep-Sea Res. 25, 673–688 (1978).

    Article  ADS  CAS  Google Scholar 

  25. Cullen, J. J. & Neale, P. J. in The Effects of Ozone Depletion on Aquatic Ecosystems(ed. Häder, D.-P.) 97–118 (Landes, Austin, (1997).

    Google Scholar 

  26. Gregg, W. W. & Carder, K. L. Asimple spectral solar irradiance model for cloudless maritime atmospheres. Limnol. Oceanogr. 35, 1657–1675 (1990).

    Article  ADS  Google Scholar 

  27. Davis, R. F., Lazin, G., Bartlett, J., Ciotti, A. & Stabeno, P. Remote sensing of a pigment patch in the southeastern Bering Sea. Proc. SPIE 2963, 654–657 (1997).

    Article  ADS  CAS  Google Scholar 

  28. Prieur, L. & Sathyendranath, S. An optical classification of coastal and oceanic waters based on the specific absorption curves of phytoplankton pigments, dissolved organic matter, and other particulate materials. Limnol. Oceanogr. 26, 671–689 (1981).

    Article  ADS  Google Scholar 

  29. Sakshaug, E., Johnsen, G., Andersen, K. & Vernet, M. Modeling of light-dependent algal photosynthesis and growth: experiments with Barents Sea diatoms Thalassiosira nordenskioeldii and Chaetoceros furcellatus. Deep-Sea Res. 38, 415–430 (1991).

    Article  ADS  Google Scholar 

  30. Denman, K. L. & Gargett, A. E. Time and space scales of vertical mixing and advection of phytoplankton in the upper ocean. Limnol. Oceanogr. 28, 801–815 (1983).

    Article  ADS  Google Scholar 

Download references


We thank members of the science team, officers and crew of the Nathaniel B. Palmer cruise NBP93-6 for assistance, W. Helbling, C. Gallegos, J. Christian, M. Lewis and B. Nieke for comments, D. Kelley for discussions of vertical mixing, M. Lesser for use of his spectroradiometers and P. Franks for providing his version of the mixing model. This work was supported by the NSF Office of Polar Programs, NSERC, NASA, and ONR Ocean Optics.

Author information

Authors and Affiliations


Corresponding author

Correspondence to John J. Cullen.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Neale, P., Davis, R. & Cullen, J. Interactive effects of ozone depletion and vertical mixing on photosynthesis of Antarctic phytoplankton. Nature 392, 585–589 (1998).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


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