2019年10月
Origin, distributions, and environmental significance of ubiquitous humic-like fluorophores in Antarctic lakes and streams
WATER RESEARCH
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- 巻
- 163
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- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1016/j.watres.2019.114901
- 出版者・発行元
- PERGAMON-ELSEVIER SCIENCE LTD
This study characterized dissolved organic matter (DOM) obtained from 47 lakes and 2 streams on ice-free areas at Lutzow-Holm Bay and Amundsen Bay in East Antarctica (n = 74), where few biogeochemical studies have been historically conducted. Samples were analyzed for basic water chemistry and by resin fractionation, UV-vis spectroscopy, and excitation emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC). Salinity of the samples ranged very broadly from fresh to hypersaline as a result of evaporative concentration. There was a clear positive correlation between log-salinity and the spectral slopes of DOM (S275-295), an indicator of photodegradation. Thus, we interpreted the correlation as a progression of photodegradation by prolonged water retention time. Of the identified seven PARAFAC components, three ubiquitous humic-like components decreased as photodegradation progressed, while a photorefractory UVC humic-like component increased its relative abundance. A non-humic component, traditionally defined as Peak N, did not show a trend depending on photodegradation, and its level was high in nutrient-rich lakes, presumably due to high in-situ production. We found robust correlations between the relative abundance of the ubiquitous humic-like components and that of the Peak N component in the bulk DOM irrespective of water types or ice-free areas. We proposed there were common processes that generated the ubiquitous humic-like components from the Peak N component in the Lutzow-Holm Bay and Amundsen Bay lakes and streams, such as bacterial processing of primary production-derived DOM and photochemical transformation of microbial DOM. (C) 2019 Elsevier Ltd. All rights reserved.
- リンク情報
- ID情報
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- DOI : 10.1016/j.watres.2019.114901
- ISSN : 0043-1354
- Web of Science ID : WOS:000483006400049