TITLE:
The Spatial and Temporal Variations of Ichythyofauna and Water Quality in the Crocodile River (East), Mpumalanga, South Africa
AUTHORS:
M. I. Soko, T. Gyedu-Ababio
KEYWORDS:
Fish, Water Quality, Nutrients, Anthropogenic Activities, Pollution
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.7 No.3,
February
12,
2015
ABSTRACT: The Crocodile River is situated in the north
east of the Republic of South Africa. It is a large river basin with a total
length of 320 km and draining a catchment of 10,450 km2. The water
quality of this river is of high importance in sustaining the people and
businesses relying on the sustainability of the river. The aim of the study was
to use fish and water quality data to determine the present ecological state of
the river and identifying the possible sources of pollution in the river.
Multivariate statistical analysis was used to identify the main contaminants in
the river at the various sections of the river. The results obtained indicated
that species richness and diversity are high during low flow condition and the
lower reaches had high species richness and diversity compared to the middle
and upper reaches. The Fish Response Assessment Index indicated that the
Ecological Class for the Crocodile River is mostly at C class beginning from
the Kwena Dam downstream. Water quality constituents such as total dissolved
solids and electrical conductivity increase with the increase in river distance
in the downstream reaches. It was evident from this study that anthropogenic
activities along the Crocodile River play a role in water quality deterioration
and the subsequent distribution of fish during high and low flow conditions.
The main sources of the pollution are believed to be agricultural activities in
the upper reaches and a combination of industrial, domestic and agricultural
activities in the middle and lower reaches of the Crocodile River.