Glacier melting and altered precipitation patterns influence Arctic freshwater and coastal ecosystems. Arctic rivers link glacier meltwaters and precipitation with the ocean through transport of particulate matter and microorganisms. However, the impact of different water sources on the microbial communities in Arctic rivers and estuaries remains unknown.
A new paper has been published in Frontiers in Microbiology with Marek as co-author, describing the bacterial community along a small river on Disko Island, W Greenland, including communities originating in a glacier and a proglacial lake. The results show that water from the glacier and lake transports distinct communities into the river in terms of diversity and community composition. Bacteria of terrestrial origin were dominating in the main river, while the glacier and lake supplied the river with water containing fewer terrestrial organisms. More psychrophilic taxa were found in the community supplied by the lake. At the river mouth, the presence of dominant bacterial taxa from the lake and glacier was unnoticeable, but these taxa increased their abundances again further into the estuary. Environmental variables showed only weak correlations with community composition, suggesting that hydrology largely influenced the observed patterns.
Hauptmann AL, Markussen TN, Stibal M, Olsen NS, Elberling B, Bælum J, Sicheritz-Pontén T, Jacobsen CS (2016) Upstream freshwater and terrestrial sources are differentially reflected in the bacterial community structure along a small Arctic river and its estuary. Frontiers in Microbiology 7:1474 doi: 10.3389/fmicb.2016.01474