Bacterial communities of surface mixed layer in the Pacific sector of the western Arctic Ocean during sea-ice melting.

• Published in: PLoS ONE
• Main Authors: Dukki Han, Ilnam Kang, Ho Kyung Ha, Hyun Cheol Kim, Ok-Sun Kim, Bang Yong Lee, Jang-Cheon Cho, Hor-Gil Hur, Yoo Kyung Lee
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2014
• Subjects: Medicine; R; Science; Q; Arctic; Arctic Ocean; Pacific; ice core; Sea ice
• Online Access: https://doi.org/10.1371/journal.pone.0086887; https://doaj.org/article/d724e585e1924a3680c2cdbb94ff9eb1

From July to August 2010, the IBRV ARAON journeyed to the Pacific sector of the Arctic Ocean to monitor bacterial variation in Arctic summer surface-waters, and temperature, salinity, fluorescence, and nutrient concentrations were determined during the ice-melting season. Among the measured physicochemical parameters, we observed a strong negative correlation between temperature and salinity, and consequently hypothesized that the melting ice decreased water salinity. The bacterial community compositions of 15 samples, includicng seawater, sea-ice, and melting pond water, were determined using a pyrosequencing approach and were categorized into three habitats: (1) surface seawater, (2) ice core, and (3) melting pond. Analysis of these samples indicated the presence of local bacterial communities; a deduction that was further corroborated by the discovery of seawater- and ice-specific bacterial phylotypes. In all samples, the Alphaproteobacteria, Flavobacteria, and Gammaproteobacteria taxa composed the majority of the bacterial communities. Among these, Alphaproteobacteria was the most abundant and present in all samples, and its variation differed among the habitats studied. Linear regression analysis suggested that changes in salinity could affect the relative proportion of Alphaproteobacteria in the surface water. In addition, the species-sorting model was applied to evaluate the population dynamics and environmental heterogeneity in the bacterial communities of surface mixed layer in the Arctic Ocean during sea-ice melting.