During the PEeCE III mesocosm experiment in 2005 we investigated how the virioplankton community responded to increased levels of nutrients (N and P) and CO2. We applied a combination of flow cytometry, Pulsed Field Gel Electrophoresis and degenerated PCR primers to categorize and quantify individual viral populations, and to investigate their temporal dynamics. Species specific and degenerated primers enabled us to identify two specific large dsDNA viruses, EhV and CeV, infecting the haptophytes Emiliania huxleyi and Crysochromulina ericina, respectively. Some of the viral populations detected and enumerated by flow cytometry did not respond to altered CO2-levels, but the abundance of EhV and an unidentified dsDNA virus decreased with increasing CO2 levels. Our results thus indicate that CO2 conditions may affect the marine pelagic food web at the viral level. Our results also demonstrate that in order to unravel ecological problems as how CO2 and nutrient levels affect the relationship between marine algal viruses and their hosts, we need to continue the effort to develop molecular markers used to identify both hosts and viruses.
Larsen, J. B., Larsen, A., Thyrhaug, R., Bratbak, G., and Sandaa, R.-A.: Marine viral populations detected during a nutrient induced phytoplankton bloom at elevated pCO2 levels, Biogeosciences Discussions, 4, 3961-3985, 2007. Article.
Final version: Larsen, J. B., Larsen, A., Thyrhaug, R., Bratbak, G., and Sandaa, R.-A.: Response of marine viral populations to a nutrient induced phytoplankton bloom at different pCO2 levels, Biogeosciences, 5, 523-533, 2008. Article.
Technorati Tags: microbe, ocean acidification, phytoplankton
