European diatoms in freshwater habitats near Arctowski Station, King George Island, maritime Antarctica

Diatom assemblages collected from ponds and pools surrounding Arctowski Station (King George Island, South Shetland Islands) have been investigated. The study focused on two groups of samples: archival samples collected in the 1990s and contemporary samples collected in 2015. All samples were analysed following the revised taxonomy. A total of 118 diatom taxa representing 38 different genera were identified. The diatom flora consisted of both species typical of the maritime Antarctica (47% of all taxa), as well as cosmopolitan species (21% of all taxa). Four European taxa (Adlafia minuscula, Nitzschia palea, Nitzschia perminuta, Surirella angusta), that have not been previously observed in Antarctica, have been recorded. The potential sources of their presence in Antarctica are discussed.