Microbial communities (bacteria, algae, fungi) on the Greenland ice sheet

The Greenland ice sheet is a crucial component of Earth's water and climate system and its surface represents the largest supraglacial ecosystem. Accelerated melt rates are increasingly contributing to sea level rise. Throughout the melt seasons glacial ice algae blooms are widespread in the so called dark zone, which is situated in the southwest of Greenland. Due to their pigmentation glacial ice algae lower the ice sheet albedo, and in turn enhance surface melting. Despite their crucial role in the ice sheet ecosystem, little is known about these algae and their associated microbiomes. Here we collected samples across a 100 km transect and from various habitats including high algal biomass ice, high algal biomass snow, biofilm, dispersed cryoconite (all macroscopically visible particles), and clean snow and clean ice (without macroscopically visible particles). The bacterial and eukaryotic (algae and fungi) community compositions were characterized using the 16S, 18S and ITS2 rRNA markers.