Njuguna, S. G.2014-01-302014-01-301988Hydrobiologia January 1988, Volume 158, Issue 1, pp 15-281573-5117http://ir-library.ku.ac.ke/handle/123456789/8880DOI 10.1007/BF00026265Seasonal variation through one year in total nitrogen (TN), total phosphorus (TP), phytoplankton biomass, phytoplankton species composition and other environmental factors were examined in Lake Sonachi, a tropical meromictic soda lake. Mean concentrations of TN and TP were 11 000 µg N l-1 and 100 µg P l-1, respectively. Maximum concentrations of TN and TP occurred in the monimolimnion. Phytoplankton biomass ranged from 350 to 1260 mg m-3. Synechococcus bacillaris, a small coccoid cyanophyte, dominated the phytoplankton. The mean chlorophyll a concentration of 37 mg • m-3 was a modest value when compared with those of other tropical soda lakes. High TN:TP ratios indicated phosphorus limitation in the lake.enNutrientsphosphorusnitrogenphytoplanktonLake SonachiKenyaArticle