title: Ice formation and growth shape bacterial community structure in Baltic Sea drift ice.
abstract: Drift ice, open water and under-ice water bacterial communities covering several developmental stages from open water to thick ice were studied in the northern Baltic Sea. The bacterial communities were assessed with 16S rRNA gene terminal-restriction fragment length polymorphism and cloning, together with bacterial abundance and production measurements. In the early stages, open water and pancake ice were dominated by Alphaproteobacteria and Actinobacteria, which are common bacterial groups in Baltic Sea wintertime surface waters. The pancake ice bacterial communities were similar to the open-water communities, suggesting that the parent water determines the sea-ice bacterial community in the early stages of sea-ice formation. In consolidated young and thick ice, the bacterial communities were significantly different from water bacterial communities as well as from each other, indicating community development in Baltic Sea drift ice along with ice-type changes. The thick ice was dominated by typical sea-ice genera from classes Flavobacteria and Gammaproteobacteria, similar to those in polar sea-ice bacterial communities. Since the thick ice bacterial community was remarkably different from that of the parent seawater, results indicate that thick ice bacterial communities were recruited from the rarer members of the seawater bacterial community.
authors.affiliation: Marine Research Centre, Finnish Environment Institute (SYKE), Erik Palménin aukio 1, PO Box 140, Helsinki 00251, Finland Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, FI-10900 Hanko, Finland eeva.eronen@gmail.com.
authors.forename: Eeva
authors.initials: E
authors.lastname: Eronen-Rasimus
authors.affiliation: Department of Food and Environmental Sciences, PO Box 56, Viikinkaari 9, FI-00014 University of Helsinki, Finland.
authors.forename: Christina
authors.initials: C
authors.lastname: Lyra
authors.affiliation: Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, FI-10900 Hanko, Finland Department of Environmental Sciences, PO Box 65, Viikinkaari 1, FI-00014 University of Helsinki, Finland.
authors.forename: Janne-Markus
authors.initials: JM
authors.lastname: Rintala
authors.affiliation: Leibniz Institute for Baltic Sea Research Biological Oceanography, Seestr. 15, 18119 Rostock, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Jürgens
authors.affiliation: Marine Research Centre, Finnish Environment Institute (SYKE), Erik Palménin aukio 1, PO Box 140, Helsinki 00251, Finland.
authors.forename: Vilma
authors.initials: V
authors.lastname: Ikonen
authors.affiliation: Marine Research Centre, Finnish Environment Institute (SYKE), Erik Palménin aukio 1, PO Box 140, Helsinki 00251, Finland.
authors.forename: Hermanni
authors.initials: H
authors.lastname: Kaartokallio
mesh_terms: D039903:Actinobacteria / Q000235:genetics; D020561:Alphaproteobacteria / Q000235:genetics; D018533:Biomass; D041965:Flavobacteriaceae / Q000235:genetics; D020563:Gammaproteobacteria / Q000235:genetics; D046448:Ice Cover / Q000382:microbiology*; D009659:North Sea; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: 16S rRNA; T-RFLP; bacteria; cloning; sea ice