Aquatic Toxicology is a multidisciplinary branch which includes study of natural and synthetic toxicants and their effects that are leading to toxicity of aquatic systems. It is a field of Science that focus on study of various chemical and physical toxins that effect biological living organisms. Source of aquatic toxicology may also include persistent toxins such as PCBs, DDT, TBT, pesticides, furans, dioxins, phenols and radioactive waste, by direct discharges via industrial and urban effluents, surface run off and indirectly from aerial fallout.