Phosphorus dynamics in shallow eutrophic lakes: an example from Zeekoevlei, South Africa
2009 (English)In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 619, 55-66 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2009. Vol. 619, 55-66 p.
Phosphorus, Primary productivity, Lake, Sediment, Dredging
Chemical Sciences Earth and Related Environmental Sciences Natural Sciences
IdentifiersURN: urn:nbn:se:su:diva-60392DOI: 10.1007/s10750-008-9600-0ISI: 000261751000005OAI: oai:DiVA.org:su-60392DiVA: diva2:434737
authorCount :52011-08-162011-08-162011-08-16Bibliographically approved