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Seasonal dynamics of carbon stable isotope ratios of particulate organic matter and benthic diatoms in strongly acidic Lake Katanuma

2003; Inter-Research Science Center; Volume: 33; Linguagem: Inglês

10.3354/ame033087

1616-1564

Hideyuki Doi, E Kikuchi, SEIICHI HINO, T. Itoh, S. Takagi, S Shikano,

Geology and Paleoclimatology Research

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 33:87-94 (2003) - doi:10.3354/ame033087 Seasonal dynamics of carbon stable isotope ratios of particulate organic matter and benthic diatoms in strongly acidic Lake Katanuma Hideyuki Doi1,*, Eisuke Kikuchi2, Shuji Hino3, Takeru Itoh3, Shigeto Takagi1, Shuichi Shikano2 1Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku Sendai 980-8577, Japan 2Center for Northeast Asian Studies, Tohoku University, Kawauchi, Aoba-ku Sendai 980-8576, Japan 3Department of Materials and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata 990-8560, Japan *Email: h-doi@cneas.tohoku.ac.jp ABSTRACT: Lake Katanuma is a strongly acidic volcanic lake (average pH 2.2) located in NE Japan in which only 2 algal species are found: Pinnularia acidojaponica, a benthic diatom, and Chlamydomonas acidophila, a phytoplankton species. Although the δ13C of phytoplankton generally varies seasonally in lake ecosystems, in Lake Katanuma the mean δ13C of particulate organic matter (POM, mainly phytoplankton) is constrained to a narrow range from -26.4 to -23.7‰. A major reason for this is the continuous supply of dissolved CO2 gas available to C. acidophila from fumaroles at the lake bottom. The δ13C of P. acidojaponica in Lake Katanuma varied seasonally and was positively correlated with P. acidojaponica abundance at 1 and 4 m depths. This suggests that the higher P. acidojaponica biomass at 1 and 4 m produced the 13C-enrichment in the high-density algal mats because of the limited dissolved CO2 gas. The mean δ13C of benthic diatoms was higher than that of phytoplankton in Lake Katanuma, although the diatoms seemed to assimilate the same carbon source (CO2 gas) in the lake water. KEY WORDS: Carbon stable isotope · POM · Phytoplankton · Benthic diatoms · Inorganic carbon · Seasonal variation · Acidic conditions Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 33, No. 1. Online publication date: August 21, 2003 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2003 Inter-Research.