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Hydrobiologia

, Volume 349, Issue 1–3, pp 65–74 | Cite as

Modelling the daily integral of photosynthesis by phytoplankton: its dependence on the mean depth of the population

  • A. E. Walsby
Article

Abstract

Detailed descriptions have been made of theunder-water light field based on continuousmeasurements of surface photon irradiance,calculations of losses by surface reflection andmeasurements of the vertical light attenuation. Thesemeasurements have been combined with measurements ofthe vertical distribution of phytoplankton chlorophylland the photosynthesis/irradiance curve to produce ameasurement of the daily integral of photosynthesis bynumerical integration using a PC spreadsheet; theaccuracy of the integrations is evaluated. The resultshave been compared with models that assume a uniformvertical distribution of phytoplankton. Suchassumptions produced underestimates of the dailyintegral of photosynthesis by 50–109% for apopulation of Aphanizomenon flos-aquae inthe Baltic Sea owing to the overestimate ofrespiratory losses. Buoyant cyanobacterial populationsfloat up during brief episodes of calm; this increasesthe insolation they receive and their resultantphotosynthetic activity may increase several times.These advantages of buoyancy, provided by gasvesicles, are a major factor in determining thesuccess of waterbloom-forming cyanobacteria. A modelis produced of the relationship between the mean depthof the Aphanizomenon phytoplankton populationand the daily integral of photosynthesis at differentinsolations; this may provide the basis forimprovement of models applicable to otherphytoplankton populations. The integration spreadsheetis available athttp://www.bio.bris.ac.uk/research/walsby/integral.htm.

daily integral of photosynthesis phytoplankton vertical distribution waterblooms cyanobacteria Aphanizomenon Baltic Sea 

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References

  1. Abramowitz, M. & I. Stegun, 1964. Handbook of Mathematical Functions. 4th edn. Washington D.C.; U.S. Government Printing Office. Dover Publications, 228–231.Google Scholar
  2. Dubinsky, Z., P. G. Falkowski, A. F. Post & U. M. van Hes, 1987. A system for measuring photosynthesis in a defined light field with an oxygen electrode. J. Plankton Res. 9: 607–612.Google Scholar
  3. Fee, E. J., 1973a. A numerical model for determining integral primary production and its application to Lake Michigan. J. Fish. Res. Bd Can. 30: 1447–1468.Google Scholar
  4. Fee, E. J., 1973b. Modelling primary production in water bodies: a numerical approach that allows vertical inhomogeneities. J. Fish. Res. Bd Can. 30: 1469–1473.Google Scholar
  5. Henley, W. J., 1993. Measurement and interpretation of photosynthetic light-response curves in algae in the context of photoinhibition and diel changes. J. Phycol. 29: 729–739.Google Scholar
  6. Humphries, S. E. & V. D. Lyne, 1988. Cyanophyte blooms: the role of cell buoyancy. Limnol. Oceanogr. 33: 79–91.Google Scholar
  7. Ibelings, B. W., 1996. Changes in photosynthesis in response to combined irradiance and temperature stress in cyanobacterial waterblooms. J. Phycol. 32: 549–557.Google Scholar
  8. Ibelings, B.W., L. M. Mur & A. E Walsby, 1991. Diurnal changes in buoyancy and vertical distribution in populations of Microcystis in two shallow lakes. J. Plankton Res. 13: 419–436.Google Scholar
  9. Jassby, A. D. & T. Platt, 1976. Mathematical formulation of the relationship between photosynthesis and light for phytoplankton. Limnol. Oceanogr. 21: 540–547.Google Scholar
  10. Kirk, J. T. O., 1994. Light and Photosynthesis in Aquatic Ecosystems. Cambridge, University Press, 509 pp.Google Scholar
  11. Platt, T., C. L. Gallegos & W. G. Harrison, 1980. Photoinhibition of photosynthesis in natural assemblages in marine phytoplankton. J. mar. Res. 38: 687–701.Google Scholar
  12. Platt, T., S. Sathyendranath & P. Ravindran, 1990. Primary production by phytoplankton: analytic solutions for daily rates per unit of water surface. Proc. r. Soc. Lond. B 241: 101–111.Google Scholar
  13. Reynolds, C. S. & A. E. Walsby, 1975. Water-blooms. Biol. Rev. 50: 437–481.Google Scholar
  14. Reynolds, C. S., 1984. The Ecology of Freshwater Phytoplankton, Cambridge University Press, Cambridge, 384 pp.Google Scholar
  15. Sathyendranath, S. & T. Platt, 1989. Computation of aquatic primary production: extended formalism to include effect of annular and spectral distribution of light. Limnol. Oceanogr. 34: 188–198.Google Scholar
  16. Smith, E. L., 1936. Photosynthesis in relation to light and carbon dioxide. Proc. natn. Acad. Sci. USA. 22: 504–511.Google Scholar
  17. Schubert, H. & R. M. Forster, 1997. Sources of variability in the factors used for modelling primary productivity in eutrophic waters. Hydrobiology 349: 75–85.Google Scholar
  18. Spencer, J.W., 1971. Fourier series representation of the position of the sun. Search 2: 172.Google Scholar
  19. Talling, J. F., 1957. The phytoplankton population as a compound photosynthetic system. New Phytol. 56: 133–149.Google Scholar
  20. Tilzer, M. M., N. Stambler & C. Loverngreen, 1995. The role of phytoplankton in decreasing the underwater light climate in Lake Constance. Hydrobiologia 316: 161–172.Google Scholar
  21. Vollenweider, R. A., 1965. Calculation models of photosynthesis depth curves and some implications regarding day rate estimates in primary production. Memorie dell’ Istituto Italiano di Idrobiologia 18: Suppl. 425–457.Google Scholar
  22. Walsby, A. E., 1994. Gas vesicles. Microbiol. Rev. 58: 94–144.Google Scholar
  23. Walsby, A. E., 1997. Numerical integration of phytoplankton photosynthesis through time and depth in a water columm. New Phytol. 136, in press.Google Scholar
  24. Walsby, A. E., P. K. Hayes, R. Boje & L. J. Stal, 1997. The selective advantage of buoyancy provided by gas vesicles for planktonic cyanobacteria in the Baltic Sea. New Phytol. 136, in press.Google Scholar
  25. Zohary, T. & R. D. Robarts, 1989. Diurnal mixed layers and the long-term dominance of Microcystis aeruginosa. J. Plankton Res. 11: 25–48.Google Scholar

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • A. E. Walsby
    • 1
  1. 1.School of Biological SciencesUniversity of BristolBristolUnited Kingdom

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