This book will provide an important source of practical information on the history of toxicology, the ways in which pollutants reach model organisms used in toxicology, sampling methods for research, mechanisms of toxicity and responses of aquatic organisms to toxic agents, as well as the use of therapeutic agents in current approaches. Determining the importance of environmentally friendly substances on antioxidant defense is an obvious area of future research. The combined use of a biomarkers range that can indicate exposure to pollutants and measure their effects on living organisms enables a more comprehensive and integrative assessment of indicator organisms in the aquatic environment, both biochemically and cellularly. In conclusion, the multiple biomarker approach had received great interest in ecotoxicological research and had recently been adapted to both field and laboratory studies.