Sea ice biota are organisms that live in, on or associated with sea ice (Horner et al. 1992, Bluhm et al. 2017a). More than 2000 species from several phyla, including viruses, bacteria, archaea, microalgae, fungi, protozoa (e.g. ciliates, choanoflagellates, amoeba, foraminifera) and invertebrates (e.g. rotifers, nematodes, copepods, amphipods) are associated with sea ice in most of their life cycle (Bluhm et al. 20I7a and b, Hassett and Gradinger 2016, Ehrlich et al. 2020, Gradinger 2020). The properties of the ice (e.g. age, thickness, light conditions, drift, etc.) determine the type of ice-associated community and its development (Syvertsen 1991, Gradinger et al. 2010, Fernandez-Mendez et al. 2018, Hop et al. 2020).