Abstract:
This study was conducted in Lake Mweru-wantipa aimed at assessing abundance of
zooplankton and its relationships with physico-chemical parameters. Four sampling
stations were selected, two on each side of the Lake; the National Park and settlement. Five
physico-chemical parameters including, temperature, turbidity, salinity, pH and dissolved
oxygen were measured monthly using portable instruments concurrently with collection of
duplet zooplankton samples at each sampling point at depths between 0.1m and 0.5m. All
physico-chemical parameters were significantly different between the two sites (p<0.05)
with the exception of temperature and pH. A total of 13 genera of zooplankton were
identified belonging to four groups namely; rotifers, cladoceran, copepods and ostracods.
The cladoceran had the highest number of species (6) followed by copepods (4) in both
sides. However, the copepods had the largest contribution in terms of abundance in both
sides. The diversity H’ was high in settlement areas but the National park had higher
species richness. There was significant difference in species diversity between the two sites
(t=3.96; p=0.001).The most abundant group was the cyclopoid in both sides of the lake
followed by the Moina on the settlement site and the daphnia sp on the National park site.
The densities of Molina, Simocephalus, Ceriodaphinia and Cypris were significantly
different between the two sites (p<0.05). With the exception of copepods all groups were
significantly different between the two sites (p<0.05). Generally, the total zooplankton
density was not significantly different between the two sites (t=0.73; p=0.06).The results
showed that the zooplankton abundance was clearly influenced by turbidity in settlement
areas and pH in National park areas. Agroforestry practices should be promoted in the
lake’s catchment area in order to reduce sedimentation in the lake and on land
deforestation.
