The effect of aeration on water quality and fish growth in the intensive culture of Nile tilapia | |
| Author | Barte, Mercy Biongan |
| Call Number | AIT Thesis no.AE-96-18 |
| Subject(s) | Nile tilapia Fish-culture |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science |
| Publisher | Asian Institute of Technology |
| Abstract | An experiment was conducted to determine the effect of aeration rate (L/min) on water quality and growth performance of Nile tilapia (Oreochromis niloticus) stocked at 6 fish/m3 in 5-m3 tanks. Treatments of aeration rates set at 0 (control), 5, 10, 15 and 20 L/min were randomly assigned to ten (10) concrete tanks. Sex-reversed all male Nile tilapia with the initial mean weight of 62 g - 75 g were stocked and fed twice a day to satiation. The mid depth diel dissolved oxygen (DO), temperature and pH levels of all treatments were monitored with automated data logger system. Vertical distribution of those parameters in the water column were monitored manually twice a week (0600 hour and 1500 hour). The other water quality parameters such as ammonia, nitrite, total alkalinity, total suspended solids, chlorophyll a and primary productivity as well as fish growth performance were monitored biweekly. Results showed that the aeration rate at 20 L/min gave the highest mean daily weight gain (4.5 g), largest mean weight (457 g) high net production (2.2 kg/m3) and low FCR (1.2). Those results, however, were not significantly different (P:2:0.05) from the treatments at 10 and 15 L/min. Although the fish growth in low aeration rate treatment (5 L/min) was not significantly different from that of higher aeration rates, it resulted in low survival (53 %) and high FCR (3.2). In the non-aerated treatment, survival was only 5 % with mean weight gain of 0.26 g/fish/day, mean weight of 169 g/fish and high FCR. Water quality parameters particularly DO concentrations and stratification affected fish survival, growth, production and FCR in the culture system. As the dawn DO concentration in the non-aerated treatment was dependent solely on the diffusion of atmospheric oxygen into the water, negative DO budgets were obtained throughout the three-month culture. In comparison, the treatment with aeration rate at 5 L/min showed adequate oxygen in the first two months but a negative DO budget was also obtained in the 3rd month of experiment. The aeration rates at 10, 15 and 20 L/min provided sufficient DO in the system. In conclusion, aeration is essential for intensive tilapia culture and the rate at 10 L/min in 5-m3 tank was optimal to maintain reasonable water quality, high fish growth and low FCR. |
| Year | 1996 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Lin, Chang Kwei; |
| Examination Committee(s) | Yakupitiyage, Amararatne;Little, David C.; |
| Scholarship Donor(s) | Government of Spain; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1996 |