Journal
MARINE POLLUTION BULLETIN
Volume 62, Issue 8, Pages 1852-1858Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.marpolbul.2011.02.050
Keywords
Photosynthetic carbon fixation; Environmental changes; Phytoplankton; UVR; Jiulong River estuary
Funding
- National Natural Science Foundation [40876058, 40930846]
- Ministry of Education of China [308015]
Ask authors/readers for more resources
Phytoplankton cells in estuary waters usually experience drastic changes in chemical and physical environments due to mixing of fresh and seawaters. In order to see their photosynthetic performance in such dynamic waters, we measured the photosynthetic carbon fixation by natural phytoplankton assemblages in the Jiulong River estuary of the South China Sea during April 24-26 and July 24-26 of 2008, and investigated its relationship with environmental changes in the presence or the absence of UV radiation. Phytoplankton biomass (Chl a) decreased sharply from the river-mouth to seawards (17.3-2.1 mu g L-1), with the dominant species changed from chlorophytes to diatoms. The photosynthetic rate based on Chl a at noon time under PAR-alone increased from 1.9 mu g C (mu g Chl a)(-1) L-1 in low salinity zone (SSS < 10) to 12.4 mu C (mu g Chl a)(-1) L-1 in turbidity front (SSS within 10-20), and then decreased to 2.1 mu g C (mu g Chl a)(-1) L-1 in mixohaline zone (SSS > 20); accordingly, the carbon fixation per volume of seawater increased from 12.8 to 149 mu g C L-1 h(-1), and decreased to 14.3 mu g C L-1 h(-1). Solar UVR caused the inhibition of carbon fixation in surface water of all the investigated zones, by 39% in turbidity area and 7-10% in freshwater or mixohaline zones. In the turbidity zone, higher availability of CO2 could have enhanced the photosynthetic performance; while osmotic stress might be responsible for the higher sensitivity of phytoplankton assemblages to solar UV radiation. (C) 2011 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available