| dc.description |
A limnological study covering the Lake Tanganyika sub catchment was conducted during the dry
season at 20 accessible sites on 8 rivers, 2 lakes and a dam. Standard methods were used to
determine the levels of abiotic parameters from water samples. Physical parameters including
EC, Eh, turbidity, temperature, pH and secchi transparency were measured in situ while
chlorophyll a was determined in the laboratory. Nutrients such as NO3
-
, SiO2, PO4
3- and Fe2+
were determined along with HCO3
-
. Significant changes in the levels of the abiotic parameters
and nutrients have been observed at various sampling sites throughout the study area. The mean
variation of NO3
-
, SiO2, PO4
3- and Fe2+ concentrations with depth ranged from 0.4 to 2.6 mg l
-1,
2.7 to 35.3 mg l
-1, 0.01 to 0.16 mg l
-1 and from <0.010 to 0.020 mg l
-1 respectively for the entire
sub catchment. Data conclude that processes including dissolution, diffusion, adsorption,
absorption, nitrification, denitrification, mixing and reduction along with the anthropogenic
activities and increased photosynthetic activity of algae contribute to the variation of the abiotic
parameters. It is recommended that quantification of river flows, sediment load and nutrient
budget at various sampling points be determined seasonally for proper evaluation of the
limnological functioning of the ecosystem. |
|