Spatiotemporal changes in communities of snow-ice microbes living on Gulkana Glacier, Alaska
- 1Graduate School of Science and Engineering, Chiba University, Japan (cryo-tardigrade@chiba-u.jp)
- 2Graduate School of Science, Chiba University, Japan
- 3Institute of Industrial Science, The University of Tokyo, Japan
- 4Earth Observation Research Center, Japan Aerospace Exploration Agency (JAXA), Japan
- 5Field Science Center for Northern Biosphere, Hokkaido University, Japan
Snow-ice microbes, which adapted to harsh conditions such as low temperature and high dose of UV, inhabit the cryospheric environments. They cause unique phenomena represented by colored snow and ice occurring with blooms of snow and glacier ice algae, and cryoconite holes formed by filamentous cyanobacteria with inorganic matter. These phenomena also darken glacial surface and have a significant effect on the albedo of snow and ice. It is important to understand factors controlling the abundance of all microbes including consumers of algae and cyanobacteria (tardigrades and rotifers) for evaluating the collective influence of biological communities on albedo (biological albedo reduction: BAR). However, most studies have focused only on each taxon (algae, cyanobacteria, fungi or heterotrophic bacteria), and there is a lack of information on whole microbial communities. In this study, we aimed to describe spatiotemporal changes of microbial communities, and discuss the process of their growth and the factors determining their distribution.
The fieldworks were carried out from June to September of 2022 on Gulkana Glacier in the Alaska Range, Alaska. Three different types of samples (snow, bare-ice, cryoconite) were collected spatially at maximum 51 points across the glacier. Microscopic observation and analysis of Chlorophyll a concentration, which is a proxy for the total abundance of snow and glacier ice algae, revealed that the algae were most abundant around the snow line and that their maximum occurred in the end of July (1.0 × 103 μg/m2) and in the middle of August (7.8 × 103 μg/m2) on the snow and ice surfaces, respectively. Their distribution in the ice area showed a similar spatial pattern throughout the season, higher abundance in the upper right side and lower in the left side. Consumers of algae (tardigrades and rotifers) were found only in the upper parts of the glacier. These results suggest that each microbial species on the glacier have different distribution and that their growth is associated with local characteristics such as microtopography of the glacier surfaces. In this presentation, we will show more data of spatial distribution of chemical composition, total impurities, and concentration of each microbe in all three surface types and discuss the factors of their growth and distribution.
How to cite: Ono, M., Takeuchi, N., Tsushima, A., Onuma, Y., Kobayashi, K., Seto, D., Usuba, S., Konishi, F., and Uetake, J.: Spatiotemporal changes in communities of snow-ice microbes living on Gulkana Glacier, Alaska, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1690, https://doi.org/10.5194/egusphere-egu23-1690, 2023.
