Present address: Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK.
Water-column stratification governs the community structure of subtropical marine picophytoplankton
Article first published online: 17 FEB 2011
© 2011 Society for Applied Microbiology and Blackwell Publishing Ltd
Environmental Microbiology Reports
Volume 3, Issue 4, pages 473–482, August 2011
How to Cite
Bouman, H. A., Ulloa, O., Barlow, R., Li, W. K. W., Platt, T., Zwirglmaier, K., Scanlan, D. J. and Sathyendranath, S. (2011), Water-column stratification governs the community structure of subtropical marine picophytoplankton. Environmental Microbiology Reports, 3: 473–482. doi: 10.1111/j.1758-2229.2011.00241.x
- Issue published online: 18 JUL 2011
- Article first published online: 17 FEB 2011
- Received 20 June, 2010; accepted 26 October, 2010.
The increase in the areal extent of the subtropical gyres over the past decade has been attributed to a global tendency towards increased water-column stratification. Here, we examine how vertical stratification governs the community structure of the picophytoplankton that dominate these vast marine ecosystems. We analysed phytoplankton community composition in the three Southern Subtropical basins of the Pacific, Indian and Atlantic Oceans using a variety of methods and show that the distributions of picocyanobacteria and photosynthetic picoeukaryotes (PPEs) are strongly correlated with depth and strength of vertical mixing: the changes in community structure occur at various taxonomic levels. In well-mixed waters, PPEs, in particular haptophytes, dominate, whereas in strongly stratified waters, picocyanobacteria of the genus Prochlorococcus are prevalent, regardless of whether the relative contributions to total biomass are assessed in terms of pigment or of carbon. This ecological diochotomy within the picophytoplankton supports the hypothesis that genomic streamlining provides a selective advantage for Prochlorococcus in highly stable, oligotrophic systems, but may restrict their ability to dominate in regions subject to dynamic mixing.