Assessment of the effects of the insecticide methyl parathion on Nile tilapia (Oreochromis niloticus) fingerling in a small-scale rice-fish culture, and on freshwater prawn juvenile (Macrobrachium rosenbergii) in tanks | |
| Author | Nguyen Thanh Phuong |
| Call Number | AIT Thesis no. AE-92-28 |
| Subject(s) | Insecticides--Toxicology Insecticides--Environmental aspects Fish-culture--Environmental aspects |
| Note | A thesis presented in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A acute bioassay was conducted to determine the toxicity of methyl parathion to Nile tilapia (Oreochromis niloticus) fingerlings (1.55 g in weight) and prawn post-larvae (Nao1·obra.chium rosenberg'ii) (0.015 g in weight). The LCso at 24 and 96 hour exposure to methyl parathion was 6.76 and 5 . 78 mg a.i./L for tilapia and 0.41 and 0.041 µg a . i . /L for prawn, respectively . The post-larvae stage of Macrobrachium rosenbergii was more sensitive to methyl parathion than tilapia fingerling. An experiment was set up in a rice field to assess the effects of methyl parathion on tilapia fingerling (1.4 2 g in weight) in a small-scale rice - fish culture system . Methyl parathion was applied at different rates (0.24, 0 . 48, 2 .4 and 4.8 mg a.i./L). At an application rate of 4.8 mg methyl parathion per liter, survival and biomass production of tilapia was significantly reduced (P <0 .01). No effects were detected at 0 . 48 mg/L or less. Fish yield was highest in control, 0.24 and 0.48 mg/L treatment, at an equivalent of 634.1, 587.4 and 415.4 kg/ha after 70 days stocking, respectively. Increase of rice yield by 13 to 30 % was recorded in all treatments with fish compared to rice fields without fish. Long- term effect of methyl parathion to Macrobrachium post - - larvae (0.12 gin weight) was investigated in a concrete-tank . Survival and biomass production of prawn were significant reduce (P<0.01) at a 4.25 and 8 . 5 µg a.i./L, applied every 10 days . No negative impact of methyl parathion to prawn at 0.21 , 0.42 and 2 . 13 µg/L, was measured in terms of survival, biomass production and growth rate. Prawn had significantly better survival rat e and yield at methyl parathion treatment of 0.213 and 0 . 425 µg/L (P<0.01). |
| Year | 1992 |
| 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) | Phillips, Michael J. |
| Examination Committee(s) | Knud-Hansen, Christopher F. ;Lin, Chang Kwei |
| Scholarship Donor(s) | The King of Thailand; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1992 |