Introduction: What is Aquatic Toxicology?

The chapter first discusses the history of aquatic contamination, highlighting major cases where aquatic contamination has become an issue and cases where efficient solutions to environmental problems have been reached. Thereafter, the hierarchy of biological functions that can be disturbed by toxicants is briefly introduced. Notably, even when the ultimate goal of toxicological research is to find out how contamination affects an ecosystem, one must remember that the toxicants affect molecular functions of the most sensitive species. Toxicological testing and its uses are then introduced. The principal available aquatic toxicology testing methods, as given by the International Organization for Standardization (ISO) and the Organisation for Economic Co-operation and Development (OECD), are tabulated and the procedure for validating toxicity tests internationally is given. An overview of important issues for aquatic toxicological research in the future is also given.