Phosphorus dynamics in shallow eutrophic lakes: an example from Zeekoevlei,South Africa |
| |
| Authors: | Supriyo Kumar Das Joyanto Routh Alakendra N Roychoudhury J Val Klump Rajesh Kumar Ranjan |
| |
| Institution: | (1) Department of Geology and Geochemistry, Stockholm University, Stockholm, 10691, Sweden;(2) Department of Geological Sciences, University of Cape Town, Rondebosch, 7700, South Africa;(3) Department of Biological Sciences and Department of Geosciences, Great Lakes WATER Institute, University of Wisconsin-Milwaukee, 600 East Greenfield Avenue, Milwaukee, WI, 53204, USA;(4) School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India |
| |
| Abstract: | Zeekoevlei is the largest freshwater lake in South Africa and has been suffering from hyper-eutrophic conditions since last
few decades. We have used total P (TP), dissolved phosphate (PO4
3−), organic P (OP), calcium (Ca) and iron (Fe) bound P fractions to investigate the relevant physical, chemical and biological
processes responsible for sedimentation and retention of P and to study phosphorus (P) dynamics in this shallow lake. In addition,
redox proxies (V/Cr and Th/U ratios) are used to study the prevailing redox conditions in sediments. Adsorption by CaCO3 and planktonic assimilation of P are found to control P sedimentation in Zeekoevlei. Low concentration of the labile OP fraction
in surface sediments restricts the release of P by bacterial remineralisation. Low molar Ca/P and Fe/P ratios indicate low
P retention capacity of sediments, and P is most likely released by desorption from wind-induced resuspended sediments and
mixing of pore water with the overlying water column.
Handling editor: J. Saros |
| |
| Keywords: | Phosphorus Primary productivity Lake Sediment Dredging |
| 本文献已被 SpringerLink 等数据库收录！ |
|
