International Journal of Aquaculture, 2013, Vol.3, No.4, 11
-
16
15
Figure 1 Location of the study sites
temperature, conductivity, total dissolved solids
were measured using electronic (Ecoscan; Australia)
meters.
All the water test meters were calibrated
before use. Surface water samples for nitrates,
phosphates and ammonia analyses were collected
using sterilised clean
500
mL
polythene bottles. The
samples were placed in a cooler box and then taken
to the laboratory for analyses.
4.3
Nutrient Analysis
In the laboratory, cadmium-reduction method was
used; colorimetric method (indophenols blue method)
and ascorbic acid methods were used for analysis of
nitrates, ammonium and orthophosphates respectively
according to
the procedures outlined in the Water
and Wastewater Examination Manual (Adams, 1989).
4.4
Data Analysis
Variations in physicochemical characteristics of the
water among sampling sites and sampling periods
were examined using two-way analysis of variance
(
Two-way ANOVA) at 5% significance level. ANOVA
was performed using the SysStat 12 for Windows version
12.02.00 (
Systat, 2007). The physicochemical parameter
values were compared with Zimbabwe’s Environmental
Management Agency (EMA) limit for surface water
effluent discharge and WHO guidelines for surface
water effluent discharge (EMA-SI, 1997; WHO, 2006).
Acknowledgements
Our heartfelt appreciation goes to crew at Lake Kariba Fisheries Research
Station for field assistance and Mr Khali and Mr Mupandawana from
University Lake Kariba Research Station for their laboratory assistance
References
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