MEPS 466:43-55 (2012)  -  DOI: https://doi.org/10.3354/meps09898

Temperature-dependent growth and photophysiology of prokaryotic and eukaryotic oceanic picophytoplankton

Gemma Kulk1,*, Pablo de Vries1, Willem H. van de Poll2, Ronald J. W. Visser1, Anita G. J. Buma1

1Department of Ocean Ecosystems, Energy and Sustainability Research Institute Groningen, University of Groningen,
9747 AG Groningen, The Netherlands
2Department of Biological Oceanography, Royal Netherlands Institute for Sea Research, 1790 AB Den Burg, The Netherlands
*Email:

ABSTRACT: It is expected that climate change will expand the open oligotrophic oceans by enhanced thermal stratification. Because temperature defines the geographic distribution of picophytoplankton in open-ocean ecosystems and regulates photophysiological responses, it is important to understand how temperature affects picophytoplankton growth and photophysiology. Two prokaryotic and 2 eukaryotic picophytoplankton strains were acclimated to 3 different temperatures, ranging from 16 to 24°C. Temperature-dependent growth and photophysiology were assessed by measurements of specific growth rates, cell size, pigment composition, absorption and electron transport rates. Growth of Prochlorococcus marinus (eMED4), Prochlorococcus sp. (eMIT9313), Ostreococcus sp. (clade B) and Pelagomonas calceolata was positively related to temperature, especially in the prokaryotic strains. Changes in photophysiology included increased light harvesting, increased electron transport and reduced photoinhibition at elevated temperatures. However, the changes related to light harvesting and electron transport could not fully explain the observed difference in growth. This suggests that other processes, such as Calvin cycle activity, are likely to limit growth at sub-optimal temperatures in these picophytoplankton strains. The overall changes in photophysiology during temperature acclimation will possibly allow photosynthesis at higher irradiance intensities, but the genetically defined low temperature tolerances and photosynthetic characteristics of the different ecotypes will likely be more important in determining picophytoplankton (depth) distribution and community composition.


KEY WORDS: Prochlorococcus · Eukaryotic picophytoplankton · Temperature · Growth · Pigment · Absorption · Electron transport rate


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Cite this article as: Kulk G, de Vries P, van de Poll WH, Visser RJW, Buma AGJ (2012) Temperature-dependent growth and photophysiology of prokaryotic and eukaryotic oceanic picophytoplankton. Mar Ecol Prog Ser 466:43-55. https://doi.org/10.3354/meps09898

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