Copper Toxicity to Tropical Water Flea Daphnia carinata and Freshwater Micro-algae Scenedesmus

Abstract

Sai Gon river is one most the most important river of South-eastern region of Vietnam by providing water resources and others vital natural services for millions of people in this area. In recent years, proportion with the sharply increasing of human activities in industry and agriculture, the river is continuously loaded with xenobiotics released by anthropogenic activities. Among pollutants, heavy metals are considered as the most toxic elements to aquatic living organisms and human health. The aim of this study is to assess the sensibility of freshwater microalgae Scenedesmus and water flea Daphnia carinata, two fresh water species from Vietnam to copper (Cu). After physical and chemical characterization, field water samples from upstream Sai Gon River was used as dilution water in toxicity tests. With water flea D. carinata, the EC50 value of 48h immobilization experiment was 1.90 µg/L. Growth inhibition of the Scenedesmus algae cells was determined following exposure for 72 h, and EC50 values was 78.2 µg/L. The results showed that Cu is highly toxic to both species, and water flea D. carinata was more sensitive than freshwater algae Scenedesmus. Based on the observed high sensitivity with Cu, both D. carinata and algae Scenedesmus are potential tools for the assessment of copper pollution in fresh water of Sai Gon river.