The Toxicity Effect of N. P. K. Agro -Fertilizer on Oreochromis Niloticus Fingerlings, the Pysiological Impact.

Abstract

The study on the acute toxicity level of inorganic fertilizer (N. P. K., 20: 10: 10) to the fingerlings of Oreochromis niloticus (mean weight 0.9 ± 0.6g) was investigated using static bioassays over a period of 96hrs intervals. The 96 hours LC50 of the exposed fishes was also determined to be 0.82sg/L with lower and upper confidence limits of 0.6 and 1.15g/L respectively. However certain stressful behavioural changes like erratic swimming with inconsistent jumping, incessant gulping of air, loss of balance, were commonly observed before death, which occurs with increase in the time of exposure. Water quality determined during the investigation showed fluctuation in oxygen content and increase in Ph, Conductivity and total dissolved solute as the concentration of the fertilizer was increased. The increased stress behavioral pattern among this fish is as a result of the increased effect of the fertilizer.

Keywards: Effects, fertilizer, Oreochromis Niloticus, fingerlings, water.