Fish productivity on the Kontagora reservoir, Niger state, Nigeria in relation to physico-chemical characteristics and Morpho–Edaphic index
A study of the physico-chemical characteristics and morpho-edaphic index in relation to its potential for fish production was conducted on Kontagora Reservoir, Niger State, Nigeria, from January to December, 2007. The physico-chemical characteristics determined bimonthly include temperature, water depth, pH, electrical conductivity, dissolved oxygen total alkalinity, phosphate-phosphorus and Nitrate-nitrogen. Morpho-edaphic index was determined using Henderson and Welcome equation. The hydrogen ion concentration (pH) (6.59–7.58), total alkalinity (26.73–65.13mg/l), conductivity (68.07–98.67μs) and dissolved oxygen (3.23–6.29) were within the range adequate for fish production. However, phosphate- phosphorus (2.84–8.31mg of CaCO3/l) and Nitrate-nitrogen (1.57–10.91mg of CaCO3/l) values were low and fell below the range necessary for fish production. The morpho-edaphic index value was low (4.15–15.54) and corresponds with low primary productivity. Therefore, the mean estimated potential fish yield of the reservoir, during the study period was low.
Keywords: fish yield, Lakes, months, sampling stations.