Bacterial communities in Arctic first‐year drift ice during the winter/spring transition

Abstract

Horizontal and vertical variability of first-year drift-ice bacterial communities was investigated along a North-South transect in the Fram Strait during the winter/spring transition. Two different developmental stages were captured along the transect based on the prevailing environmental conditions and the differences in bacterial community composition. The differences in the bacterial communities were likely driven by the changes in sea-ice algal biomass (2.6-5.6 fold differences in chl-a concentrations). Copiotrophic genera common in late spring/summer sea ice, such as Polaribacter, Octadecabacter and Glaciecola, dominated the bacterial communities, supporting the conclusion that the increase in the sea-ice algal biomass was possibly reflected in the sea-ice bacterial communities. Of the dominating bacterial genera, Polaribacter seemed to benefit the most from the increase in algal biomass, since they covered approximately 39% of the total community at the southernmost stations with higher (>6 μg l(-1) ) chl-a concentrations and only 9% at the northernmost station with lower chl-a concentrations (<6 μg l(-1) ). The sea-ice bacterial communities also varied between the ice horizons at all three stations and thus we recommend that for future studies multiple ice horizons be sampled to cover the variability in sea-ice bacterial communities in spring.

An active bacterial community linked to high chl-a concentrations in Antarctic winter-pack ice and evidence for the development of an anaerobic sea-ice bacterial community

“…In addition, both the bacterial production and abundance correlated with the chl-a concentrations (Spearman's ρ: 0.63, P: 2.291 × 10 − 6 , ρ: 0.83, P: 1.51 × 10 − 11 ), further supporting the coupling between the algal and bacterial communities. The coupling of the sea-ice bacterial community composition and chl-a has been also previously reported in early spring and summer sea ice (Cowie et al, 2014;Eronen-Rasimus et al, 2016). However, a previous mid-winter study showed no correlation between chl-a and bacterial biomass likely because of the low chl-a concentrations in the ice (Stewart and Fritsen, 2004).…”

A Differential Metabarcoding Approach to Describe Taxonomy Profiles of Bacteria and Archaea in the Saltern of Margherita di Savoia (Italy)

“…It is a selenoid-shaped photoheterotroph organism, consisting of actinorhodopsin molecules for light energy transduction. After the first isolation, "Candidatus Aquiluna" members were identified in Arctic sea waters, and brackish ice brine [52][53][54][55] and Indian brackish coastal waters [56]. Notably, "Candidatus Aquiluna" was identified as the dominant phylotype in brackish ice brine, which has a lower salinity than immediate sub-ice seawater [55].…”

Bacterial community structure in a sympagic habitat expanding with global warming: brackish ice brine at 85–90 °N

“…For example, the Chukchi Sea is one of the most productive seas on Earth [67]. Some ice-core studies in the Arctic shelf LMEs report dominance of Gammaproteobacteria [68,69], whereas others report dominance of Alphaproteobacteria [53,70] or more or less equal abundances of Gammaproteobacteria, Alphaproteobacteria and Flavobacteriia [64,70]. This variability seems to be independent of the age of the ice (perennial or annual) and more related to the proximity of land, which strongly influences trophic state.…”

“…In ice cores from the CAO, Halomonas and Shewanella were extremely rare, with one read each of 12,352 reads [9]. The genus Halomonas consists of salttolerant bacteria [90] and has rarely been reported from the Arctic region [69], whereas more records exist from Antarctica [11,91]. Shewanella has been found in the Arctic region more often, mainly in sediments [92], but also in snow in the CAO [81].…”

“…Candidatus Aquiluna was initially characterised as a freshwater bacterium by Hahn [94] but was later reported from many different environments [93]. In the Arctic region it has been found in surface ice and SW near Svalbard [69,93] and the Chukchi Sea [62], but not in the CAO and also not in a study targeting phototrophic bacteria in the Beaufort Sea [95].…”