Lisa Schellenberg^1,2, Henk Bolhuis³, Andreas Haas³ and Corina PD Brussaard^2,3, (1)Royal Netherlands Institute for Sea Research, Marine Microbiology & Biogeochemistry, Ben Burg, Netherlands, (2)University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Amsterdam, Netherlands, (3)Royal Netherlands Institute for Sea Research, Marine Microbiology & Biogeochemistry, Den Hoorn, Netherlands