Ecotoxicology of Copper on Local Freshwater Organisms in Mekong River Cambodia

Abstract

The protection of aquatic habitat from damage and understanding of both sensitivity of aquatic organisms to contaminant and ecological effects. Mekong River quality criteria of aquatic life for metals are largely driven by the extremely sensitive small organisms toxicity which are the Mekong native species. In this study we assessed the toxicity of Copper in the Mekong river water with Chironomids Species (Chironomus javanus) and Nile tilapia (Oreochromis niloticus). Acute toxicity effect of copper concentration to freshwater animals occur after the exposure at tested with Mekong water was studied by observing mortality and LC₅₀ over a 24 hours test period. The LC₅₀ with 95% confidence limit of the 96-hours toxicity was performed to contrast responses of Chironomids Species (C. javanus) and Nile tilapia (O. niloticus). The result showed that the LC₅₀ with 95% confidence limit obtained were 742μg/L in Chironomids Species (C. javanus) and 853μg/L in Nile tilapia (O. niloticus). Copper (Cu) is a big concern for environment, human and aquatic organisms because it can accumulate in to plant and animals via food web. The out coming of this series of laboratory experiment will provides a worst-case scenario and useful for determine the risk assessment of copper on local freshwater organisms in Mekong River Cambodia as well as Mekong River Basin.