Assessing cryptic non-fungal eukaryotic diversity associated with rocks at Lions Rump, South Shetland Islands, Maritime Antarctica

Maritime Antarctica experiences less extreme environmental conditions than much of the Antarctic continent and has further been impacted by considerable warming in recent decades. While inventories exist of macroscopic Antarctic biodiversity, and there is some information available on culturable microorganisms, much less is known about the presence of other cryptic eukaryotic organisms. DNA metabarcoding provides a method for assigning the DNA of multiple different organisms simultaneously from environmental samples. In this study, we used DNA metabarcoding to investigate the environmental DNA (eDNA) diversity of non-fungal eukaryotic organisms associated with rocks in the South Shetland Islands. Five sampling points were selected from a stratigraphic profile at Mazurek Point, King George Island. Collected rock samples were pulverized, total DNA was extracted and amplicons were generated using ITS2 primers, then these were sequenced using an Illumina MiSeq system. Sequences representing five kingdoms and nine phyla were retrieved. Viridiplantae was the most diverse and abundant group, with 42 assigned taxa, followed by Chromista, with 22 assigned taxa. The precise lithology did not influence the assigned diversity. The majority of assigned taxa are widespread and plausibly present in the area, but some are not known from Antarctica, including some from tropical regions. The latter assignments probably result from the limitations of the databases used, although in some cases they may indicate evidence of anthropogenically associated or naturally dispersed DNA-containing material.