Influence of tanks liner material on water quality and growth of Clarias gariepinus

Three tank liner materials: polyvinylchloride (PVC), polyethylene and polyester were evaluated in a 93 days experiment for their influence on culture water quality and growth performance of Clarias gariepinus. Fish of average weight of 5.03±0.21g were stocked at 375 per m3 in tanks lined with the aforementioned materials. Fish were hand fed twice a day. Growth performance and water quality parameters were measured using standard methods. Average temperature of 25.09±1.14OC was recorded in the tanks. Dissolved oxygen with the highest mean value of 5.41±0.96 mg/l was recorded in polyethylene lined tanks while the highest mean alkalinity value of 110.38±2043mg/l was obtained in polyester lined tank .Fish cultured in PVC lined tanks recorded the highest mean daily growth rate of 4.87±3.87g while polyester lined tanks recorded the lowest mean value of daily growth rate of 2.95±2.08g. Highest mean food conversion ratio was recorded in PVC lined tanks with the value of 1.59±0.70. Highest mean weight of 22.59±1.56g was obtained in PVC lined tanks while the least mean weight of 15.41±1,11g was obtained in polyethylene lined tanks. Fish cultured in PVC lined tanks had better growth performance when compared to other tanks liner materials. It would be beneficial with respect to fish growth and culture water quality, to use polyvinylchloride materials in lining fish culture ponds and rearing tanks.Keywords : Aquaculture, Liners, Fish Farming, Tank, Clarias gariepinu

Effects of the Shape of Culture Tanks on Production of the African Catfish Clarias Gariepinus Juveniles

An 84-day laboratory experiment was conducted to determine the effects of different tank sections on production of the African catfish Clarias gariepinus juveniles of average weight (10.65 ± 0.07g). Three culture tank shapes (circular, rectangular and square) made of plastic material, having the same surface area and volume were used. The fish were fed 45% CP floating pellets at 3% body weight twice daily throughout the experimental period. Weight gain, percentage weight gain, feed conversion ratio, specific growth rate, profit index and gross profit were used to determine growth and cost of production. There was no significant difference (P > 0.05) in growth parameters of the fish in all the treatments. However, the highest weight gain, specific growth rate, profit index and gross profit were obtained in circular tank compared to other tank shapes. Similarly, circular tank gave the least cost of production and has many advantages for fish culture compared to other shapes

Effect of aeration on selected water quality parameters in freshwater fish culture

This paper report findings of an investigation into the effect of aeration devices on some selected freshwater quality parameters. Three aeration columns, Upturned shower rose (USR), Downturned shower rose (DSR) and Perforated pipe (PEP) were experimented. Freshwater fish culture water was passed through the devices and analysed for Temperature, pH, Alkalinity and Dissolved oxygen (DO) in the morning, afternoon and evening. The percentage modification was used to measure the effect of aeration on the selected water quality parameters. Temperature modification ranged from -2.4% to 0% with equal value in all the aeration devices at all the period, Alkalinity ranged between -10.7% and 3.7% with least modification in DSR in the morning but highest in USR in the evening, The percentage modification in pH fell between -8.3% and -1.8% with the least modification in USR in the morning while the highest was recorded also in USR but in the evening. The DO ranged between 37.1% to 161.9% with the highest modification in DSR in the afternoon and the lowest in USR in the evening. The investigated aerating devices have little effect on all the selected water quality parameters, except for dissolved oxygen where the effect is very prominent.Keywords: Aeration columns, aquaculture, downturned shower rose, freshwater quality, perforated pipe, upturned shower rose

Evaluation of Moringa oleifera seed as coagulation aid for treatment of fish farm effluents

Laboratory tests were carried out to evaluate the potentials of Moringa oleifera seed powder as a coagulation aid for removal of suspended particles in fish culture effluent. The standard jar test was used to investigate the dosage and mixing intensity required to optimize the use of the coagulant in removing of suspended particles from wastewater from a commercial, adult African Catfish culture facility. The evaluation was done at coagulant dosages 0, 60, 90, 120 and 150 mg/l and at three mixingintensities 100, 150 and 200 revolutions per minute. Appreciable differences were observed in the mean turbidity values recorded at the various dosages applied (P<0.05) while differences in turbidity values between the mixing speeds were not significant (P>0.05). At low dosages, percentage increase rather than reduction was obtained with elevated turbidity levels while at dosages above 60 mg/l, percent reduction in turbidity as high as 39% at 120 mg/l coagulant mixed at 150 rpm was obtained. Results indicate that Moringa oleifera seed powder can be effective in the treatment of fish culture wastewater as a coagulation aid to effect suspended solids removal.Keywords: Coagulation, Moringa Wastewater, Turbidity, Fish cultur

Effluents Characteristics of Selected Industries in Western Nigeria and Implications for re-use in Agricultural Production

Wastewater characteristics provide basic information for their possible reuse for agricultural production as irrigation water and for fish culture. Pre-treated wastewater effluents from five industrial establishments were investigated to determine their potential of being used for irrigation and aquaculture. The physico – chemical analysis of the effluents indicates that most conform to recommended FAO (1992) and FEPA (1991) indicating potentials of being utilized for agricultural purpose. Exception occur in the total dissolved solids (TDS) and Nitrate (NO3-) contents which is found to be very high in most of the effluents sampled. pH analysis shows that effluent from food and beverage industries tend to be very acidic. The data so obtained in this study shows that the utilization of the pre-treated effluent from these industries for agricultural purpose could be encouraged with minor modification by further treatment Journal of Environmental Extension Vol.4 2003: 79-8