Comparison of pelagic prokaryotic communities between two ice shelf regions of the Southern Ocean in late austral summer

• Main Author: 신동영
• Other Authors: 황청연, Shin Dong Young, 자연과학대학 지구환경과학부
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 서울대학교 대학원 2023
• Subjects: 남빙양; 표영성 원핵생물 군집; 용융수; 550; Southern Ocean; Austral; Ross Sea; Amundsen Sea; Dotson Ice Shelf; Ice Shelf
• Online Access: https://hdl.handle.net/10371/197318; https://dcollection.snu.ac.kr/common/orgView/000000178727

학위논문(석사) -- 서울대학교대학원 : 자연과학대학 지구환경과학부, 2023. 8. 황청연. Ice shelf regions in the Southern Ocean are highly productive areas where dynamic water masses exist and large amounts of basal melt occur, but little is known about how environmental variables in the region influence marine prokaryotes and their activities. By sequencing the 16S rRNA gene, this study conducted a comparative analysis on pelagic prokaryotic community compositions of ice shelf regions, especially the Dotson Ice Shelf (DIS) region in the Amundsen Sea and the Nansen Ice Shelf (NIS) region in the Ross Sea. The results showed distinct patterns of prokaryotic community compositions in each region based on corresponding water masses. In the DIS region, Flavobacteriia were found to be prevalent in the epipelagic zone, whereas in the NIS region, Alphaproteobacteria emerged as the dominant taxa in the same zone. In both regions, the mesopelagic zone exhibited high species richness, with a wide range of taxa associated with important microbial processes in deep-sea environments. Notably, the prokaryotic communities in the DIS region exhibited notable variations in relation to distances from the ice shelf. These variations strongly indicate the evident influences of meltwater, including the high relative abundance of Nitrosopumilus spp. in the meltwater-influenced area. Overall, the study provides insights into the differentiated compositions of epipelagic and mesopelagic prokaryotic communities in the DIS and NIS regions, highlighting the importance of meltwater influences on pelagic prokaryotic communities in ice shelf regions. 남빙양의 빙붕 지역은 역동적인 수괴 움직임과 대량의 기저 용융이 나타나는 고생산성 지역으로, 이 지역의 환경 변수가 해양의 원핵생물과 그들의 활동에 어떤 영향을 미치는지에 대해서는 아직 알려지지 않은 바가 많다. 본 연구는 16S rRNA 유전자 시퀀싱을 통해 남극의 빙붕 지역, 그 중에서도 아문젠해의 닷슨 빙붕 지역(Dotson Ice Shelf, DIS)과 로스해의 난센 빙붕 지역(Nansen Ice Shelf, NIS)의 표영성 원핵생물 군집 조성에 대한 비교 분석을 수행하였다. 그 결과 각 지역과 수괴에 대응하는 독특한 표영성 원핵생물 군집 조성의 패턴이 나타났다. 닷슨 빙붕 지역에서는 Flavobacteriia가 상대적으로 풍부하게 나타났으며, 난센 빙붕 지역에서는 Alphaproteobacteria가 동일한 깊이에서 우세한 생물종으로 나타났다. 양 ...