Studies on the recovery potentials of a disturbed aquatic ecosystem: Focus on pre-and post-dredging analysis of Nworie River, Owerri, Imo State, Nigeria
Date
2014-06
Journal Title
Journal ISSN
Volume Title
Publisher
U. P
Abstract
A study was done to monitor the recovery potential of Nworie river system, in Imo State, Ni- geria from July 2010 to January 2012. Water samples were collected from 5 Stations prior to, during and after dredging. Station 1 was the dredging point, Stations 2 and 3 were 250m and 500m upstream of the point, while Stations 4 and 5 were 250m and 500m downstream of the dredging point respectively. The physicochemical parameters of the water before dredging were assessed to be within acceptable limits of established water standards; pH 6.5-7.8, Tem- perature 27.6-29.9 °C, Conductivity 34-196us/cm, Turbidity 0-76NTU, TDS 22.1-127.4 mg/l, TSS 9-51mg/l, Nitrate 1.2-33.6mg/l, Phosphate 0.2-3.7mg/1, Sulphate 0-33mg/l, DO 4.3- 9.4mg/l and BOD5 9.5- 10.9mg/l. During the dredging, the water physicochemistry changed noticeably with indices outside the permissible limits of the standards. The pH values de- creased drastically to 4.6, DO to 1.3mg/l, Nitrate to 1.2mg/l, temperature increased to 30.2°C, Turbidity 620NTU, TSS 349mg/l, Conductivity 498 μs/cm, TDS 298.8 mg/l, BOD5 19.1mg/l, Sulphate 33mg/l and Phosphate 0.92mg/l. Three months after the dredging, the values for the parameters returned to their pre-dredging concentrations. However, during the rainy season, as the leachates and silts from the spoils were washed into the river, the recovery of the river sys- tem was prolonged to about 9 months. This implies that the effects of dredging on the river are short term, but improper disposal of dredge spoils compounded the impacts.
Description
the article contains tables
Keywords
Recovery potentials, disturbed aquatic ecosystem, pre-and post-dredging analysis, Nworie River, Imo State, Nigeria, Department of Biotechnology
Citation
Udensi, J. U., Iwuala, M. O. E., Nwigwe, H. C., Onyedineke, N. E., Okereke, J. N. & Mgbemena, I. C. (2014). Studies on the recovery potentials of a disturbed aquatic ecosystem: Focus on pre- and post-dredging analysis of Nworie River, Owerri, Imo State, Nigeria. International Journal for Environmental Health & Human Development, 15(1), 42 - 49