Effect of turbidity on pond fish culture | |
| Author | Ratchada Mhoryadee |
| Call Number | AIT Thesis no. AS-97-08 |
| Subject(s) | Fish-culture Nile tilapia Fish ponds Turbidity |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AS-97-08 |
| Abstract | The impact of turbid water on the fish production of small-scale farmers in rainfed area of Udornthani province Northeast Thailand was investigated in the field and through controlled experiments. Field work was conducted to identify factors causing turbidity in fish ponds by interviewing sixty farmers in Udornthani provinces and sampling soil, and water for laboratory analysis at AIT. The soil series most identified with persistent turbidity problem were Udorn, Phen and Roiet series. The level and nature of turbidity in ponds with these different soil series were not significantly different. Pond condition pond management were identified by farmers as important factors increasing turbidity in fish pond and in its alleviation. The dominant cause of turbidity in the study area was identified by farmers as soil texture and erosion. Turbidity was significantly (p<0.05) more severed in the dry and early wet season than later in the year. Two experiment to evaluate the effect of turbidity on the growth and reproduction Nile Tilapia (Oreochromis niloticus) were conducted in 5m2 tank at AIT. Two treatments in which a high level of turbidity was maintained the Phen ('red') and Roiet series ('white') were compared to unfertilized ('clear') and fertilized ('green') water. Nile Tilapia (Oreochromis niloticus) were stocked at a rate of 6 fish/m2 and fed with a floating pelleted feed at a rate of 5% of initial body weight once a day over the 70 days period. The net fish yields were 11.03, 7.07, 7.03, and 8.53 g/m2 /day in 'green', 'red', 'white' and 'clear' water respectively. Yield in 'green' water were significantly (p<0.05) higher than 'clear' water which in term performed better than both turbid treatments. Food conversion efficiency showed a similar trend. Experiment 2 broodfish was stock at a density of 6 fishes/m2 (F: M= 1) and fed a floating pelleted feed at a rate of I% of body weight per day over 84 days experimental period. Total seed production and number of spawner was not significantly different reproductive output varied between 21.7 to 31.4 seed/m2 /day and 7.4 to 9 seed/female/day and differences were not significantly different between treatment. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AS-97-08 |
| 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 Aquatic Systems(AS) |
| Chairperson(s) | Little, David C. ; |
| Examination Committee(s) | Edwards, Peter ;Hansen, Gunner K.; |
| Scholarship Donor(s) | Danida; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1997 |