Phosphorus dynamics in shallow eutrophic lakes: an example from Zeekoevlei, South Africa

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, chemica...

Full description

Saved in:
Bibliographic Details
Published in:Hydrobiologia 2009-02, Vol.619 (1), p.55-66
Main Authors: Das, Supriyo Kumar, Routh, Joyanto, Roychoudhury, Alakendra N, Val Klump, J, Ranjan, Rajesh Kumar
Format: Article
Language:English
Subjects:
Animal and plant ecology
Animal, plant and microbial ecology
Biological and medical sciences
Biomedical and Life Sciences
Chemistry
Dredging
Earth sciences
Ecology
Eutrophic environments
Eutrophic lakes
Eutrophication
Fresh water ecosystems
Freshwater
Freshwater & Marine Ecology
Freshwater lakes
Fundamental and applied biological sciences. Psychology
General aspects
Geochemistry
Geovetenskap
Kemi
Lake
Lakes
Life Sciences
Limnology
NATURAL SCIENCES
NATURVETENSKAP
Phosphorus
Pore water
Primary productivity
Primary Research Paper
Resuspended sediments
Retention
Retention capacity
Sediment
Sedimentation
Synecology
Water column
Zoology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0018-8158
1573-5117
1573-5117
DOI:10.1007/s10750-008-9600-0