Characterization of nutrients enrichment in the estuaries and related systems in Kenya coast

Abstract

Rivers Tana, Sabaki, Umba and Ramisi discharge their waters into the Indian Ocean along the Kenyan coastline. This study was carried out to examine the river nutrient input characteristics in terms of PO4 3--P, (NO2-+ NO3-)-N and NH4+-N concentration trends and their interactions with TSS, Chl a, DO and BOD5, along the estuaries of these rivers, and the contiguous coastal systems. Standard methods were used for sample collection preparation and analysis. Sabaki and Tana estuaries PO43- -P and (NO2-+ NO3-)-Nlevels (means± SD) were 0.145 ±0.075 mg/L and 5.133 ±3.39 mg/L respectively and were significantly higher compared to the other estuarine systems considered in this study. There were significant correlations between the nutrients and other variables suggesting the influence of nutrients on the overall water chemical and biological characteristics. In conclusion the study identified River Sabaki as the greatest contributor to marine pollution, by contributing the greatest quantities of nutrients and suspended matter. The study recommends measures aimed at counteracting this environmental problem at its very source, the catchment.