This book, the first of its kind in this subject area, will focus on in vitro approaches to the study of the toxicology of polluting agents (including heavy metals, radionuclides, micro-organics, estrogenic compounds, and complex mixtures) in the aquatic environment. The importance of in vitro methods is that they allow standardised techniques to be developed and validated for substance and species specific experiments in a controlled way. Also, they allow mechanistic studies without the problems of individual variation between animals and environmental stress.