Influence of water quality in semi-intensive production systems on Nile tilapia production in Soroti district.

Abstract

The study was conducted to determine the levels of water parameters·(temperature, pH dissolved oxygen, nitrate and chlorophyll) and their effect on Nile. tilapia productivity in earthen ponds. All ponds were sampled once, recording of water quality parameters. and weight of fish was done ranging from 1 to 7 times. Most ponds were, poorly maintained with a lot of vegetative growth and organic matter which led to such observations in the parameters. Mean pH was weakly alkaline ranging. from 7.1 to. 7.8 mean temperature. ranged from 22.9 (pond 1) to 28.1 (pond 4); least DO concentration was 0.78 mg/l (pond 2) and highest was 8·07 mg/L (pond 5); concentrations of chlorophyll were generally low, ranging from 0.13m/L (pond 6) to O.007 mg/L (pond S): nitrate ranged from 0,06 to 0.13 mg/L. The weight of- fish ranged from as low as 8.3g to 429g. Most parameters showed no significant effect on weight of fish apart from chlorophyll a (p<0.05) but there was. a significant variation of water: quality. parameters among ponds (one-way ANOVA). In recommendation, Nile tilapia is a warm water species thus siting of fish ponds in swamps detrimentally affects its productivity as swamps have cold environments as fish growth depends on its immediate environment