Aspects of the limnology of Kuti stream, Abaji Area Council, Federal Capital Territory, Abuja, Nigeria

Abstract

Physicochemical parameters of Kuti stream, Abaji Area Council, Abuja were studied for twelve months (January - December, 2019).  Water samples were collected from the study area monthly from four sampling points that were 500 m distance apart into a clean 2-litre transparent plastic container and screw capped between the hours of 06.00 – 10.00. Samples were preserved in ice and taken to the laboratory for analysis. Temperature, pH, electrical conductivity (EC) and total dissolved solids (TDS) were measured in-situ with portable HANNA meter (HI 70007 pH/EC/TDS/̊C), while chloride (Cl ^- ), sodium (Na ⁺ ), nitrate (NO₃ ^- ), phosphate (PO₄^{3 -} ), sulphate  (SO₄ ^2- ), magnesium (Mg ²⁺ ), potassium (K ⁺ ), calcium (Ca ²⁺ ), dissolved oxygen (DO), alkalinity and turbidity were analyzed ex-situ using standard methods. Descriptive statistics revealed that all parameters were within permissible limits recommended by the World Health Organization (WHO) and FRN’s national environmental (surface and underground water quality control) regulations except PO₄
^3- and turbidity. Analysis of Variance showed that all parameters are significantly different (p˃0.05) except pH across sampled points,
while paired sample t-test showed that there was a significant difference (p<0.05) of all parameters between seasons except pH and Na. The high concentration of PO₄^3- and turbidity observed may be linked to the influx of runoff from nearby farms and degree of
anthropogenic activities that took place in the stream during the study. PO₄ ^3- combined with NO_{3 ^-} to cause eutrophication, which lead to higher oxygen demand and subsequent death of aquatic organisms. To reduce the concentration of PO₄ ^3- , sustainable agriculture and healthy activities around the stream should be practiced.

Keywords: Kuti Stream, Physicochemical parameters, Water  quality, Seasonal dynamics, Anthropogenic activities