1. Institute of Chemistry and Biology of the Marine Environment, University of Oldenburg, Schleusenstrasse 1, 26382 Wilhelmshaven, Germany
2. Present address 1: BioPol ehf., Einbúastig 2, 545 Skagaströnd, Iceland
3. Present address 2: Faculty of Natural Resource Sciences, University of Akureyri, Borgir v. Nordurslod, IS 600 Akureyri, Iceland
4. Oceanlab, University of Aberdeen, Main Street, Newburgh AB41 6AA, Scotland, UK
5. Department of Biology, Section of Protistology and Aquatic Ecology, University of Ghent, Krijgslaan 281 S8, 9000 Ghent, Belgium
6. Institute of Biological Sciences, Applied Ecology & Phycology, University of Rostock, Albert-Einstein-Strasse 3, 18059 Rostock, Germany