Growth, Hematological Evaluation and Heavy Metal Bioaccumulation in Nile Tilapia (Oreochromis niloticus) from A Municipal Waste Landfill Reservoir

Abstract

The aim of this study was to evaluate the growth performance, mortality rate, and blood profile of Cd-, Pb-and Cr-contaminated Nile tilapia from the Khon Kaen municipal waste landfill reservoir and compare the parameters with those of fish from unpolluted sites. Human bioaccumulation factor (BAF) determination was also performed. Thirty samples of Nile tilapia were taken from the Khon Kaen municipal waste landfill reservoir (CN) and from unpolluted (TN) ponds. Water and soil were collected from these sites, and tilapia muscle, gill, and liver were obtained for heavy metal evaluation. The Cd concentrations in the muscle, gill and liver were 0.003 ± 0.001, 0.006 ± 0.008, and 0.004 ± 0.003 mg/kg; the Pb concentrations were 0.078 ± 0.173, 0.880 ± 1.360 and 1.110 ± 1.862 mg/kg; and the Cr concentrations were 0.067 ± 0.135, 0.572 ± 1.098 and 0.636 ± 1.272 mg/kg, respectively. The total fish length, body weight and survival rate were significantly lower in the TN group (P <0.05), and alanine aminotransferase and creatinine were significantly (P <0.05) higher in the TN group. The hematocrit count of the TN group was also lower than that of the CN group but without a significant difference. The BAF ranged from 0.1-4.3, especially in the gills and liver, which are major heavy metal accumulation organs. Heavy metal contamination in landfill leachate negatively affects fish health and its production. Keywords: Aquaculture, Nile tilapia, Heavy metal, Pathology, Toxicity