Impact of Anthropogenic Activities on the Zooplankton Community of Aba River in Aba, Abia State

Abstract

The effect of anthropogenic activities on zooplankton community structure and abundance of the Aba River was studied in five sampling stations for a period of four (4) months. The study showed mean physicochemical parameter value range of temperature 26.7oC–27.7oC, pH 6.7-6.9, salinity 0.11o/o – 0.19o/o, turbidity 0.49–1.35NTU, nitrate 0.28–0.59mg/l, phosphate 0.05±0.01mg/l–0.09±0.06mg/l, dissolved oxygen 10.17–15.43mg/l, and biochemical oxygen demand 3.82 – 6.53mg/l. The biological analysis result showed a total of 14 zooplankton species belonging to 6 taxa. The family Rotifera had the highest number of zooplankton in total, with 1103 indiv/l (or 84.7%), followed by Cladocera and Protozoa with 62 indiv/l (4.8%), Copepod 57 indiv/l (4.4%), Insect 10 indiv/l (0.7%), and Crustacea 8 indiv/l (0.6%). The maximum Shannon-Weiner index of diversity per station per month was 1.730 in station 4 in July. The minimum (0.537) was at station 2 in September. The Megalef Richness Index varied from 1.91 to 2.85. The evenness index (E) ranged from 0.498 to 2.05. It was therefore concluded that anthropogenic activities and nutrient input into the water body influenced the species composition, distribution, and abundance of the plankton community of the Aba River.