Dissolved oxygen as an indicator of water pollution in abandoned mine pits used for fish farming
The inability of some old mine pits to serve as fishponds in Ishiagu mining zone was investigated. The physical and chemical nature of the pits and waters were studied and the results pointed at low oxygen concentration in the waters. Using the electrometric membrane analysis method, the level of oxygen dissolved in them was found to be between 2.97mg/l and 3.27mg/l in the unproductive ponds while it requires 4.0mg/l or more to support fish life. The situation was created by the heavy quarry wastes dumped in these pits as well as the great depths of these pits. It was concluded that dissolved oxygen concentration in an enclosed water body could be an indicator of its viability for fish rearing.
IJONAS Vol. 3 (1) 2007: pp. 77-80