These proceedings provide the reader with recent advances in the study of planktonic cycling of matter and energy, placing a strong emphasis on the effects of eutrophication on these processes. This book covers a wide range of topics in the field, including: nutrient limitation of phytoplankton growth; nutrient cycles in the planktonic food web + DOM sources, composition, and uptake; resource limitation vs shaping of the food web by grazing; spatio-temporal variability - coupling of physical and biological processes; processes controlling sinking losses from the pelagic system; planktonic food web modelling. The book should be of interest to everybody involved in planktonic ecosystem research, from the advanced student to the distinguished scientist. This volume brings to the reader the knowledge of international authors on the main issues of ecological plankton research.