The Influence of a Eutrophic Lake to the River Downstream: Spatiotemporal Algal Composition Changes and the Driving Factors

Water

Qian Yu¹  Yongcan Chen¹  Zhaowei Liu¹  Nick van de Giesen²  Dejun Zhu¹ 

[1] State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China; E-Mails:;Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, PO Box 5048, 2600 GA Delft, The Netherlands; E-Mail:

关键词: eutrophication;    phytoplankton structures;    Microcystis;    hydrodynamic conditions;    turbidity;   

DOI  :  10.3390/w7052184

来源: mdpi

【 摘 要 】

Algal blooms have been frequently found at the upper reaches of the Tanglang River, which is downstream from the eutrophic Dianchi Lake. The eutrophic lake upstream is considered to be a potential source of phytoplankton, which contributes to the development of harmful algal blooms in the river downstream and can cause many serious problems for the river ecology. However, few studies focused on these kinds of rivers. Therefore, a field observation and laboratory analysis were conducted in this study. The results showed that the Tanglang River was obviously spatially heterogeneous due to the eutrophic Dianchi Lake upstream. The toxic Microcystis from the Dianchi Lake dominated the phytoplankton at the upper reaches, but these were gradually, rather than immediately, replaced by centric diatoms and chlorococalean green algae in the middle and lower reaches. The results of correlation analysis indicated that the changes in hydrodynamic conditions and underwater light intensity accounted for the spatial variations. The differences in the adaptability of different algae to changing aquatic environments explained the spatial variations of phytoplankton abundance. The dominant algae, most of which was from the Dianchi Lake upstream, determined the characteristics of the total abundance at the Tanglang River.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.