Impact of Agriculture Fertilizer Containing Nitrogen on Oxygen Consumption of Freshwater Fish; Tilapia mossambica

Shailendra S.. Mangalawede, Ramesh S. Gani

Abstract: In present days excessive fertilizers are using in the agriculture fields to get good crops. Some times these fertilizers enter in to fresh water bodies through run off with rain water. Fishes living in these fresh water bodies which are surrounded by these fields have to face problems evoked by nitrogen containing fertilizers and other fertilizers. Hence present investigation is to study the effect of nitrogen contained fertilizers on oxygen consumption of the fresh water fish Tilapiamossambica. The effect of nitrogen - containing chemical fertilizers like urea on oxygen consumption in Tilapia mossambica was investigated. Fishes were collected from Belur Pond in the Belur village of Dharwad taluk of Karnataka, India. Fishes were exposed to different urea concentrations for 96 hours to investigate oxygen consumption by fish in the water. Dissolved oxygen was carried out by Wrinkle's titrimetric method before and after the administration of fish into different concentrations of urea. LC50 value was detected. The urea concentrations prepared were 0g/lit (control), 3g/lit, 6g/lit, 9g/lit, 12g/lit, and 15 g/lit. Fishes were exposed to different urea concentrations in separate aquariums for 96 hour. After 96 hours, dissolved oxygen consumed by the fishes in control and aquariums containing different urea concentrations were estimated. It was investigated that the amount of oxygen consumption by fishes decreased if urea concentration was increased. Furthermore, it was investigated that the mortality of fingerlings increases with increasing urea concentrations. Thus it was shown that urea affects the oxygen consumption of fish in freshwater ecosystems. The present investigation showed that an increase in urea concentration might result in decreased oxygen consumption

Keywords: Urea, Freshwater, Belur, Dissolved oxgen,, Ecosystems