Hydrobiologia publishes original research, reviews and opinions investigating the biology of freshwater and marine environments, including the impact of human activities. We welcome molecular-, organism-, community- and ecosystem-level studies in contributions dealing with limnology and oceanography, including systematics and aquatic ecology. Hypothesis-driven research is preferred, but conceptual papers or articles with large descriptive content will also be considered. In all cases, the investigation has to be clearly embedded in a theoretical framework and be relevant to a broad hydrobiological audience. Applied aspects will be considered if firmly embedded in an ecological context.   Hydrobiologia is no longer a preferred publication avenue for purely physical, chemical or toxicological studies, unless a clear link to biological aspects can be demonstrated. Special issues on timely topics shall be considered through invitation by the editor. Identical standards of acceptance are rigidly applied for both special and regular issues.