Determination of lethal concentration of Aluminum, Copper and Zinc (LC50-96h) on Nile tilapia larvae (Oreochromis niloticus)

Assessing the toxic effects of pollutants in the early stages of life of living organism, along with other aspects of aquatic toxicology, helps to better understand toxicity of contaminants and to plan for coping with the conditions created. Aluminum, zinc and copper are some of the trace elements that are increasing in aquatic ecosystems due to human activities. In this study, the acute toxicity of aluminum, copper and zinc were investigated on the survival of the Oreochromis niloticus fish yolk sac larvae and the lethal concentration (LC50-96h) was determined based on the OECD 203 protocol. For this purpose, 200 pieces of larvae with a weight range of 0.0132-0.0156 g and total length of 4.25- 4.75 mm, exposed to different concentrations of aluminum (zero (control), 24, 28.8, 34.56, 41.47, 49.76, 59.71 and 71.65 mg/l), zinc (0 (control), 10, 12, 14.4. 17.28 and 20.73 mg/l) and copper (zero (control), 0.625, 1.25, 2.5, 5 and 10 mg/l) for 96 hours. The mortality was recorded at 24, 48, 72 and 96 hours. The physical and chemical parameters of water were also measured daily. Using probit regression analysis, LC50-96h for aluminum, copper and zinc was 61.839, 1.397 and 14.056 mg/l, respectively. The concentrations were determined at 95% confidence interval in mg / l for aluminum 55.449-67.851, copper 1.157-1.637 and zinc 12.293-16.411. The results, proved that copper was more toxic than zinc and aluminum in tilapia fish larvae.