Variations of δ15N-Values and Hydrolyzable Amino Acids in Settling Particles in the Ocean
作者:
P. Schäfer,
V. Ittekkot,
G. Gravenhorst,
R. Langel,
A. Reineking,
期刊:
Isotopes in Environmental and Health Studies
(Taylor Available online 1998)
卷期:
Volume 34,
issue 1-2
页码: 191-199
ISSN:1025-6016
年代: 1998
DOI:10.1080/10256019708036346
出版商: Taylor & Francis Group
关键词: Amino acids;Bay of Bengal;degradation;δ15N-value;marine nitrogen cycle;particle flux;sediment;settling particles
数据来源: Taylor
摘要:
The modification of nitrogen isotopic signals during particle sedimentation in the sea is of great interest for the use of sedimentary δ15N-values as a paleoceanographic tool. The effect of organic matter degradation on such modification was studied by analyzing nitrogen, hydrolyzable amino acids (THAA) and δ15N-values in a suit of marine settling particles collected from the Bay of Bengal, Indian Ocean, by using time-series sediment traps, and in underlying sediments. The flux of settling particles showed temporal variations which are related to the monsoons, the major climatic feature of this marine region. During high flux periods settling particles are enriched in nitrogenous material that is less degraded and exhibit higher δ15N-values than particles showing characteristics of degradation. At the sediment surface more than 95% of the settling particulate nitrogen is lost and the δ15N-values of the residual sedimentary nitrogen are higher than those of settling particles. The observed increase is interpreted to be due to fractionation during degradation of organic matter.
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