Modeling phytoplankton growth rates

Mathematical models of planktonic ecosystems use a variety of different formulations to relate phytoplankton growth rates to environmental conditions. Does the formulation influence the model result? We have modified the model of Fasham, Ducklow and McKelvie (/. Mar. Res., 34,591- 639, 1990) to test how its results would respond to changes in algal growth rate formulations. The original model uses a Monod relationship between nutrient concentration and relative growth rate, and a multiplicative rule to combine light and nutrient effects. Use of a Droop formulation for algal growth rate or a threshold (Blackman's law) mechanism to combine light and nutrient limitation produced significant changes in simulation results. One important effect was to increase zooplankton population and, as a result, the regenerated production. While there are aesthetic reasons to prefer these alternate formulations, a more accurate formulation will require more laboratory work on algal physiology. Such laboratory work should be encouraged as an adjunct to modeling work.

[1]  Richard C. Dugdale,et al.  NUTRIENT LIMITATION IN THE SEA: DYNAMICS, IDENTIFICATION, AND SIGNIFICANCE1 , 1967 .

[2]  F. Morel,et al.  KINETICS OF NUTRIENT UPTAKE AND GROWTH IN PHYTOPLANKTON 1 , 1987 .

[3]  Donald L. DeAngelis,et al.  Multiple nutrient limitations in ecological models , 1989 .

[4]  John J. Walsh,et al.  Death in the sea: Enigmatic phytoplankton losses , 1983 .

[5]  Trevor Platt,et al.  Mathematical formulation of the relationship between photosynthesis and light for phytoplankton , 1976 .

[6]  A. Vézina,et al.  Biological Production of the Oceans - the Case for a Consensus , 1989 .

[7]  T. G. Richards,et al.  Elementary kinetics of membrane carrier transport , 1972 .

[8]  John Caperon,et al.  Population Growth in Micro-Organisms Limited by Food Supply. , 1967, Ecology.

[9]  E. Hofmann,et al.  Plankton dynamics on the outer southeastern U.S. continental shelf. Part II: A time-dependent biological model , 1988 .

[10]  J. Wroblewski,et al.  A model of phytoplankton plume formation during variable Oregon upwelling , 1977 .

[11]  Eileen E. Hofmann,et al.  Plankton dynamics on the outer southeastern U.S. continental shelf. Part III: A coupled physical-biological model , 1988 .

[12]  Dennis A. Hansell,et al.  Chemical characterization of three large oceanic diatoms: potential impact on water column chemistry , 1992 .

[13]  P. R. Sloan,et al.  RELATIONSHIP BETWEEN CARBON CONTENT, CELL VOLUME, AND AREA IN PHYTOPLANKTON , 1966 .

[14]  J. Goering,et al.  UPTAKE OF NEW AND REGENERATED FORMS OF NITROGEN IN PRIMARY PRODUCTIVITY1 , 1967 .

[15]  J. Sarmiento,et al.  Ecosystem behavior at Bermuda Station “S” and ocean weather station “India”: A general circulation model and observational analysis , 1993 .

[16]  H. Ducklow,et al.  A nitrogen-based model of plankton dynamics in the oceanic mixed layer , 1990 .

[17]  B. Marcos,et al.  Comparison of six models for nutrient limitations on phytoplankton growth , 1987 .

[18]  J. Toggweiler,et al.  Downward transport and fate of organic matter in the ocean: Simulations with a general circulation model , 1992 .

[19]  P. Tett,et al.  A model for the growth of shelf-sea phytoplankton in summer , 1986 .

[20]  J. C. Goldman,et al.  Nitrogenous Nutrition of Marine Phytoplankton in Nutrient-Depleted Waters , 1979, Science.

[21]  J. Steele,et al.  The role of predation in plankton models , 1992 .

[22]  A. Devol,et al.  Nitrogen in the Marine Environment , 1985 .

[23]  M. Droop.  SOME THOUGHTS ON NUTRIENT LIMITATION IN ALGAE 1 , 1973 .

[24]  Robert R. Bidigare,et al.  Seasonal patterns of ocean biogeochemistry at the U.S. JGOFS Bermuda Atlantic time-series study site , 1994 .

[25]  J. C. Goldman.  Potential role of large oceanic diatoms in new primary production , 1993 .

[26]  David A. Siegel,et al.  Seasonal variability of light availability and utilization in the Sargasso Sea , 1995 .

[27]  G. Evans,et al.  Towards a model of ocean biogeochemical processes , 1993 .

[28]  M. Fasham,et al.  Modelling the Marine Biota , 1993 .

[29]  D. Burmaster.  The Continuous Culture of Phytoplankton: Mathematical Equivalence Among Three Steady-State Models , 1979, The American Naturalist.

[30]  E. Laws,et al.  A microalgal growth model , 1990 .

[31]  J. C. Goldman,et al.  Steady state growth and ammonium uptake of a fast‐growing marine diatom 1 , 1978 .

[32]  Paul J. Harrison,et al.  PHYSIOLOGICAL ACCLIMATION OF MARINE PHYTOPLANKTON TO DIFFERENT NITROGEN SOURCES 1 , 1993 .

[33]  J. Toggweiler,et al.  A seasonal three‐dimensional ecosystem model of nitrogen cycling in the North Atlantic Euphotic Zone , 1993 .

[34]  Q. Dortch,et al.  The interaction between ammonium and nitrate uptake in phytoplankton , 1990 .

[35]  F. F. Blackman.  Optima and Limiting Factors , 1905 .

[36]  E L Smith,et al.  Photosynthesis in Relation to Light and Carbon Dioxide. , 1936, Proceedings of the National Academy of Sciences of the United States of America.

[37]  J. Walsh.  A spatial simulation model of the Peru upwelling ecosystem , 1975 .

[38]  J. Tintoré,et al.  Modelling the deep-chlorophyll maximum : a coupled physical-biological approach , 1992 .

[39]  J. Ryther,et al.  The annual cycle of primary production in the Sargasso Sea off Bermuda , 1959 .