The study of the effects of a chemical substance on aquatic species is known as aquatic toxicity, and it is usually done on organisms representing the three trophic levels, namely vertebrates (fish), invertebrates (crustaceans like Daphnia), and plants (algae). Because water and food are the principal channels for harmful compounds to reach animals in the aquatic environment, chemical and physical causes of sickness in aquatic creatures are usually linked to them.
To assess the toxicity of effluents to aquatic life, short-term sublethal studies are utilized. The EPA developed these procedures, which primarily focus on the most vulnerable life phases. Changes in growth, reproduction, and survival are among the test's endpoints.