Hannah Gaber^1,2, Carla López Mateo², Samuel Hermant^2,3, Kaat Paepen^2,4, Pieter Hovenkamp⁵, Dick van Oevelen⁶, Lorenz Meire⁷, Koen Sabbe⁸, Ulrike Braeckman^2,9 and Jan Vanaverbeke^2,9, (1)Protistology and Aquatic Ecology, Dpt. of Biology, Ghent University, Ghent, Belgium, (2)Marine Biology, Dpt. of Biology, Ghent University, Ghent, Belgium, (3)Institute of Natural Sciences, Brussels, Belgium, (4)Vrije Universiteit Brussel, Brussels, Belgium, (5)Royal Netherlands Institute for Sea Research (NIOZ), Dpt. of Estuarine and Delta Systems, Yerseke, Netherlands, (6)Royal Netherlands Institute for Sea Research (NIOZ), Department of Estuarine and Delta Systems, Yerseke, Netherlands, (7)Greenland Institute of Natural Resources, Nuuk, Greenland, (8)Laboratory of Protistology and Aquatic Ecology, Ghent University, Ghent, Belgium, (9)Institute of Natural Sciences, MARECO, Brussels, Belgium