Abstract
M.Sc.
Owing mostly to the ephemeral nature, pan wetlands aren’t afforded the attention that other
(arguably) more attractive or functional wetland types entertain. In the Kruger National Park,
the study of its freshwater resources has focused mainly on the water quality of its rivers
leaving pans almost entirely unaccounted for, until now. The aims of this study were to
determine a baseline assessment of the structural, hydrological, physico-chemical and
biological characteristics of eight selected seasonal pans in the Kruger National Park.
The results of this study show that the pans are relatively small (<1.3 hectares), shallow (from
0.4 to 1.1metres), of various shapes and can hold a greater volume of water where greater
depth and increasingly concave basin profiles are present. The physico-chemical characteristics
typically showed high summer sub-surface water temperatures (up to 38°C), anaerobic
conditions, pH values of 6.2 to 7, low alkalinity, varied conductivity, turbid conditions and
generally could be described as oligotrophic in terms of nutrients. The dominant anion in most
cases was sulphate. Iron was the dominant metal in the water chemistry of the pans. Several
dissolved metals in the water chemistry of the pans were relatively high in concentration
including aluminium, zinc, copper, cadmium, lead and selenium when evaluated against
national water quality standards. Overall, limited spatial and temporal similarities were
observed between the pans in terms of the physico-chemical characteristics of the water.
The sediment of the pans can be considered as high in organic content, generally moist and
comprising of predominantly either very fine sand sediments or coarse sand with appreciable
amounts of medium coarse sediments. In general, manganese was the most abundant metal in
the sediments, followed by relatively high concentrations of chromium, nickel, copper and zinc
when compared with international sediment quality standards. Correlations between metal
concentrations, sediment size and organic content were not strong.Lastly, the degree of grass
cover for some pans show remarkably similar variation in the degree of change with distance
from the brim of the pans outward. The trees immediately surrounding the pans however, are
diverse and generally correspond with earlier studies of the vegetation of the Kruger National
Park.