The Toxic Effects of Commonly Used Antibiotics in Turkey on Aquatic Organisms

Antibiotic pollution has the potential to directly affect the health of people, animals and the ecosystem. The presence of antibiotics in the environment can impede the structure of microbial community, having both acute and chronic effects on microbial and planktonic communities. In Turkey, the three most prevalent antibiotics detected in aquatic environment are Amoxicillin, Tetracycline and Nitrofurantoin, but there is almost no information on their toxicity on natural microbial communities. Particularly, there is no data available for marine microorganisms. While the amount of toxicity levels for humans is well known, there is less knowledge about toxic concentration in wildlife, especially smaller and more vulnerable organisms. Consequently, the purpose of this current study is to evaluate the acute toxicity of Amoxicillin, Tetracycline and Nitrofurantoin to the natural water ecosystem, a complex ecological group comprising a variety of bacterial and planktonic species. It is seen that antibiotics are practically non-toxic (>100 mg/L) in the classification of acute toxicity according to Daphnia magna. It is not possible to mention about toxicity in this case, but when considering the toxicity of antibiotics among themselves, the ranking is like Tetracycline > Nitrofurantoin > Amoxicillin. The same toxicity ranking is encountered in the acute toxicity test made with Vibrio fischeri. However, in the acute toxicity test made with Vibrio fischeri, the results are toxic for Tetracycline (2.53 mg/L), Nitrofurantoin (15.67 mg/L) and Amoxicillin (56.23 mg/L). While antibiotics have an acute effect on bacterial structures, they tend to have a chronic effect and bioaccumulation properties on Daphnids.