Possible interactions between bacterial diversity, microbial activity and supraglacial hydrology of cryoconite holes in Svalbard

Abstract

The diversity of highly active bacterial communities in cryoconite holes on three Arctic glaciers in Svalbard was investigated using terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA locus. Construction and sequencing of clone libraries allowed several members of these communities to be identified, with Proteobacteria being the dominant one, followed by Cyanobacteria and Bacteroidetes. T-RFLP data revealed significantly different communities in holes on the (cold) valley glacier Austre Brøggerbreen relative to two adjacent (polythermal) valley glaciers, Midtre Lové nbreen and Vestre Brøggerbreen. These population compositions correlate with differences in organic matter content, temperature and the metabolic activity of microbial communities concerned. No within-glacier spatial patterns were observed in the communities identified over the 2-year period and with the 1 km-spaced sampling. We infer that surface hydrology is an important factor in the development of cryoconite bacterial communities.

Microbial community changes along the Ecology Glacier ablation zone (King George Island, Antarctica)

“…Their presence has been connected with decreased albedo of cryoconite sediment, higher water temperatures, and a subsequent increase in microbial activity (Stibal et al 2006;Edwards et al 2011). Our data suggest that the PHAC/TC ratio and tetrazolium reducing activity in Ecoplates increased in cryoconite samples in which SUVA measurements were elevated.…”

“…Many researchers investigating glacial microbiota have collected samples along a transect like ours (Mindl et al 2007;Uetake et al 2010;Edwards et al 2011;Zarsky et al Fig. 5 Principal component analysis of microbiological data in surface ice (black diamonds) and cryoconite samples (circles).…”

Biocryomorphology: Integrating Microbial Processes with Ice Surface Hydrology, Topography, and Roughness

“…In the Arctic, Irvine-Fynn et al (2012) demonstrate that water flow through the near-surface porous ice ("weathering crust") facilitates microbial transport downglacier. Moreover, Edwards et al (2011) infer that surface hydrology modulates cryoconite bacterial community structure and function. As Cook et al (2015) discuss, cryoconite holes penetrate the weathering crust and offer long term storage for mineral and organic matter, as well as being natural piezometers indicative of meter-scale weathering crust hydrology.…”

Ecology and biogeochemistry of cyanobacteria in soils, permafrost, aquatic and cryptic polar habitats

“…These species are considered opportunistic organisms with wide ecological roles and strong colonizing potential, rather than glacial specialists. Although one 16S rRNA gene-based clone library study suggested that cyanobacteria are not predominant bacterial members within High Arctic cryoconite holes (Edwards et al 2011). A recent study employing deep sequencing showed that cyanobacteria, namely Microcoleus and Phormidium were the most abundant bacterial groups in cryoconite located in Svalbard located in the high Arctic (Edwards et al 2011).…”