This book presents an integrated discussion on ecotoxicology, containing both general concepts and specific ecotoxicological issues of major biological groups, extending beyond conventional systems. It explores worldwide, regional, and biocompartmentalized topics, bringing forth new points of view on global issues and addressing the increasing diversity and complexity of the ecotoxicological field. It also contains novel information on emerging contaminants, presents bioaccumulation effects on different levels of ecological organization and risk analyses, and discusses novel fields of methodological applications, including key aspects in ecotoxicological and environmental monitoring studies.