High protein production of phytoplankton in the Amundsen Sea

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• 作者：Ho Jung Song^a ; Jae Jung Kang^a ; Bo Kyung Kim^a ; HuiTae Joo^a ; Eun Jin Yang^b ; Jisoo Park^b ; Sang Hoon Lee^b ; Sang Heon Lee^a ; ^{sanglee@pusan.ac.kr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Amundsen Sea ; Polynya ; Phytoplankton ; Macromolecular production ; Protein
• 刊名：Deep Sea Research Part II: Topical Studies in Oceanography
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：123
• 期：Complete
• 页码：50-57
• 全文大小：1443 K

文摘

The Amundsen Sea polynya is one of the largest and most productive polynyas in the Southern Ocean and has recently experienced a rapid change in sea ice coverage. However, very little is known about current physiological status of phytoplankton and its quality as food for pelagic herbivores and consequently higher trophic levels in the Amundsen Sea. Using a ¹³C isotope tracer technique, macromolecular production measurements of phytoplankton at eleven stations were conducted at three light depths (100, 30, and 1%) onboard R/V ARAON in the Amundsen Sea, 2012. The concentrations of major inorganic nutrients were replete at all the productivity stations and no substantial difference in macromolecular production was found between polynya and non-polynya regions. Distinct vertical trends were not observed in low-molecular-weight metabolites (LMWM) and polysaccharide productions, but weak vertical patterns in lipid and protein productions were found during our cruise period. The vertical patterns of lipids slightly increased with depth whereas decreased for protein synthesis in this study, and these vertical trends were not consistent with the results reported previously in the Arctic Ocean. Overall, phytoplankton allocated more photosynthetic carbon into proteins (60.0%) than other macromolecules in the Amundsen Sea, which is markedly higher than those reported previously in the Antarctic Ocean, ranging from 7 to 23%. The high protein synthesis appears to be sustained by high concentrations of major nutrients, which might be a strong factor for general patterns of macromolecular productions of phytoplankton in polar oceans, even under potential iron limitation.