title: Bacterial communities from Arctic seasonal sea ice are more compositionally variable than those from multi-year sea ice.
abstract: Arctic sea ice can be classified into two types: seasonal ice (first-year ice, FYI) and multi-year ice (MYI). Despite striking differences in the physical and chemical characteristics of FYI and MYI, and the key role sea ice bacteria play in biogeochemical cycles of the Arctic Ocean, there are a limited number of studies comparing the bacterial communities from these two ice types. Here, we compare the membership and composition of bacterial communities from FYI and MYI sampled north of Ellesmere Island, Canada. Our results show that communities from both ice types were dominated by similar class-level phylogenetic groups. However, at the operational taxonomic unit (OTU) level, communities from MYI and FYI differed in both membership and composition. Communities from MYI sites had consistent structure, with similar membership (presence/absence) and composition (OTU abundance) independent of location and year of sample. By contrast, communities from FYI were more variable. Although FYI bacterial communities from different locations and different years shared similar membership, they varied significantly in composition. Should these findings apply to sea ice across the Arctic, we predict increased compositional variability in sea ice bacterial communities resulting from the ongoing transition from predominantly MYI to FYI, which may impact nutrient dynamics in the Arctic Ocean.
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Ido
authors.initials: I
authors.lastname: Hatam
authors.affiliation: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.|Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada.|Zoological Institute and Zoological Museum, Biocenter Grindel, University of Hamburg, Hamburg, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Lange
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Justin
authors.initials: J
authors.lastname: Beckers
authors.affiliation: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada.|Department of Earth and Space Sciences and Engineering, York University, Toronto, Ontario, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Haas
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Lanoil
mesh_terms: D001110:Arctic Regions; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D002170:Canada; D046448:Ice Cover / Q000382:microbiology*; D010802:Phylogeny; D012621:Seasons; D012623:Seawater / Q000382:microbiology*