It has been known that continental shelves around the Arctic Ocean play a major role in the ventilation of the deep basins as a consequence of shelf-basin exchange. In the present study, we found that bacterial assemblage of the surface sediment was different from that of seawater while seawater harboured local bacterial assemblages in response to the Arctic hydrography. This finding suggests that the Arctic seafloor sediments may have distinctive bacterial biogeography. Moreover, the distribution of bacterial assemblages and physicochemical properties in surface sediments changed gradually from the Arctic continental shelf to deep-sea basin. Based on the results, bacterial biogeography in the Arctic seafloor sediments may be influenced by winnowing and re-deposition of surface sediments through the sediment gravity flow. The present study offers a deeper understanding of shelf convection and its role for the construction of bacterial assemblages in the Arctic Ocean.
Bibliographical noteFunding Information:
This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2012R1A1A2043811), the Polar Academic Program (PD12010 and PD15010) of KOPRI, and the Basic Research Projects in High-tech Industrial Technology through a grant provided by GIST in 2015. S. I. N. is supported by Basic Research Program (PE15062) of KOPRI. All authors thank Dr. G. T. Lee in the National Instrumentation Center for Environmental Management (NICEM) for the grain size analysis using laser diffraction. We also thank the crew members and scientists of the ARAON who assisted with sample collections at sea.