Microflora Community And Diversity Of Pack Ice In The Arctic Canada Basin During Summer

During the period of the 6th Chinese Arctic Expedition in August 2014, samples from melting pond, sea ice and underlying sea water of 7 ice camps in Canada Basin were collected and epifluorescent microscopy was utilized for the analysis of bacteria and protist communities. The result showed that bacteria was the first dominant group and heteroflagellates was the second dominant group, with the biomass percentage of 42.8%.37.8%,50.7%; 40.2%.34.3%.37.5%, respectively (the data from ICE07 melting pond with algal bloom was not included). Heterotrophic organisms like bacteria.heteroflagellates and ciliates dominate within the community, which suggests that microbial loop may play an important role in the community of pack ice zone. Under the background of quick melting of sea ice in summer, the environments of all three habitats were unsuitable for quick growth of the community and the biomass were very low. An an autotrophic flagellate bloomwas observed in a melting pond and surface 20 cm ice column on ICE07. We suggest that both suitable algal seed and nutrient supplement are essential for the occurrence of algal bloom on the surface ice.During the period of the 4th Chinese Arctic Expedition in August 2010, samples from melt pond, sea ice and underlying sea water in central Arctic Ocean were collected and pyrosequencing approach was utilized for the study of bacteria community compositions and diversity. Moreover, by comparing the bacterial community composition among different habitats, results from 19 samples indicate the presence of local bacterial communities. Flavobacteria and Alphaproteobacteria are dominant in closed melt pond and in opened melt pond, respectively. Gammaproteobacteria are dominant in ice core, while Alphaproteobacteria are dominant in underlying sea water. The process of ice core melting into closed melt pond was also the process of bacteria species adapting and sorting. The differences in bacteria community between ice core and closed melt pond should be further studied. Salinity is an important factor that affects the proportion of bacteria community compositions when closed melt pond became opened melt pond. The differences of bacteria community compositions between opened melt pond and underlying sea water may be related to the duration of the opened melt pond. As the sea ice provenance is different among ice camps, compositions of bacteria community is also different.