1. Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research , Am Handelshafen 12 , 27570 Bremerhaven , Germany
2. Applied Ecology and Phycology , University of Rostock , Albert-Einstein-Straße 21 , 18059 Rostock , Germany
3. Department of Algal Development and Evolution , Max Planck Institute for Developmental Biology , Max-Planck-Ring 5 , 72076 Tübingen , Germany