Ulrike Hanz, NIOZ Royal Netherlands Institute for Sea Reasearch, den Hoorn, Netherlands, Marcel van der Meer, NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, 't Horntje, Netherlands, Philip Riekenberg, NIOZ Royal Netherlands Institute for Sea Reasearch, Netherlands, Jasper M De Goeij, University of Amsterdam, Freshwater and marine ecology, Amsterdam, Netherlands, Martijn Bart, University of Amsterdam, Netherlands, Erik Wurz, Wageningen University and Research, Netherlands, Anna de Kluijver, Utrecht University, Netherlands, Hans Tore Rapp, University of Bergen, Bergen, Norway, Gert-Jan Reichart, Royal Netherlands Institute for Sea Research, Den Burg, Netherlands and Furu Mienis, NIOZ, Den Burg, Netherlands