1. University of Innsbruck, Institute of Botany, Department of Physiology and Cell Physiology of Alpine Plants, Innsbruck, Austria
2. University of Rostock, Department of Biology, Institute of Aquatic Ecology, Albert‐Einstein‐Straβe 3, 18051 Rostock, Germany
3. Foundation Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany