ABSTRACT

Study on the limnological survey of Ihie stream in Olokoro Umuahia South L.G.A. of Abia State was carried out from June to August 2013 with the aim of determining the water quality parameters as well as the plankton abundance of the stream. water samples were collected twice monthly with clean 1.5 litre bottle from the sampling site and was taken to the laboratory for analysis of pH, dissolved oxygen, biological oxygen demand, nitrates and phosphates. Temperature and transparency were determined in0site. water samples for plankton analysis were sieved through 55 µm plankton net size. The values of physic-chemical features obtained show that the highest mean value for dissolved oxygen (6.12±0.47) were recorded in August with the lowest mean value (4.49±0.01) recorded in June. Biochemical oxygen demand was highest in August with mean value of (7.56±0.09). pH values were recorded lowest in June with mean value of (6.85±0.02) alkalinity was observed to be highest in August with mean value of (78.34±2.91) and lowest in June with mean (69.39±0.24). Nitrate has the highest mean value (4.71±0.04) in August and least in June with mean value of (3.39±0.04). Phosphate has the lowest value in June with mean of (2.74±0.38). Transparency was observed to be highest in June with mean value of (23.50±2.12) and least in August with mean value of (20.00±0.00). Temperature recorded the highest value in August (29.00±0.00) and least in June with mean value of (26.50±0.71). The results of the biological analysis show that Rotifera were the most abundant zooplankton constituting about 21 % of the total zooplankton abundance, followed by Glossosoma with 17.7% of the total abundance, protozoa 17.2%, Cladocera 15.8%, copepod 14.4 % and the least in abundance were Hypotrichidium with 13.6 % of the total abundance. The phytoplankton population shows that Euglena is the highest phytoplankton recorded in the stream during the period of study it has about 27.4% of the total abundance and numerically it was found highest in August, July and June having about 18.50, 17.50, 14.00 numbers respectively. Spirogyra spp is the second in total abundance with about 21.1% of total abundance, followed by Cyclotella with 14.2% total abundance, Oscil/atora were the least in abundance with 10. 7% of the total abundance. Ihie stream like other inland water bodies of the Niger delta Zone of Nigeria faces serious anthropogenic activities such as bathing, washing of clothes, agricultural runoffs and industrial runoffs. These activities have caused serious pollution to the stream and the drinking water quality degraded. There is therefore need to monitor and control human activities that go on in and around the stream so as to save the already polluted state of the stream and enhance the drinking water quality of the stream.