Diversity of cyanobacteria and microalgae in coastal terrestrial ecosystems, Lützow-Holm Bay, East Antarctica

Photosynthetic cyanobacteria and microalgae are adapted to various extreme environments (cold, dry and/or ultra-oligotrophic conditions). Continental Antarctica is an extreme environment because of its high latitude, harsh climate and ice cover. The Antarctic terrestrial ecosystem has low biological diversity. However, ice-free regions, which include only 3% area have relatively rich ecosystems dominated by cyanobacteria, microalgae, lichens, and mosses. Understanding the diversities of photosynthetic microorganisms in these environments is important because they are primary producers and their spatial distribution and diversity are changing at present. The coastal area around Syowa station (69°00’ S, 39°35’ E) in Lützow-Holm Bay, East Antarctica, contains many ice-free regions. In these regions, Japanese Antarctic Research Expedition has investigated the terrestrial ecosystems from ecological, taxonomic and physiologic points of views. Here, we conducted a sampling campaign in Langhovde (50 samples), Skarvsnes (52), Skallen (26), Ongul Island (6), Inhovde (10), Padda Island (4) and Amundsen Bay (15), during the Antarctic austral summer in 2018-2019 (163 samples). The samples were collected from different habitats: lakes, shallow wetlands ponds - streams, biological soil crusts, snow, seashores, etc. Then, cyanobacteria and microalgae diversity were identified by light microscopy together with a description of the most important environmental parameters. Samples were sorted into different groups for more detailed taxonomical and ecological analyses. In this presentation, we introduce a diversity map of photosynthetic organisms in the studied area of the East Antarctic. This research is supported by JARE-60 2018/19 and contributes to the long-term biological diversity monitoring of Antarctic terrestrial ecosystem.