The rising temperatures associated with climate change could lead to increased ice melt on the Antarctic continent, causing the expansion of ice-free areas. With the decreasing distance between these areas, connectivity increases, which could have a significant impact on Antarctic ecosystems. Antarctic biota are characterized by high levels of endemism, likely as a result of their isolation and long-term evolution in glacial refugia. The combination of higher connectivity and a milder climate could enhance the establishment of invasive species and increase competition, which eventually could lead to the loss of endemic species and biotic homogenization. The HabitAnt project aims to assess how Antarctic freshwater systems could evolve under different climate change scenarios by studying the past and present habitability of lakes and their catchments. To achieve these goals, dated lake sediment cores from the Larsemann Hills, Syowa Oasis and Schirmacher Oasis will be analysed. Ancient DNA will be extracted from the cores and a metabarcoding approach will be used to assess biological succession over time and in response to environmental changes. We have already redesigned metabarcoding primers for the invertebrate taxa Copepoda, Cladocera, Rotifera, Ostracoda and Tardigrada. Furthermore, for one core of the Schirmacher Oasis, 18S rRNA and fossil pigment data are already available. Metabarcoding data will be complemented with microfossil analyses, and time-calibrated phylogenies will be constructed from the obtained aDNA sequencing reads. In addition, recent lake sediment samples will be analysed to assess the present-day community structure of freshwater biota in different lakes. The obtained datasets will allow us to determine locations of glacial refugia and to study processes such as colonization, long-term persistence in glacial refugia, diversification and extinction. We will also model optima and tolerances for several important environmental factors, enabling us to predict how freshwater biota might respond to future environmental changes.
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RBINS Staff Publications 2023
