ABSTRACT
Eutrophication is a global problem caused by nutrient enrichment, notably phosphorus and nitrogen. In extreme cases of eutrophication algae decomposition may cause oxygen depletion, resulting in the death of most organisms living in the body of water. Methods of counteracting eutrophication which are based on this traditional limnological approach are physical in nature, e.g., water aeration, chemical precipitation of phosphates, or bottom sediment removal. Biological or biomanipulation methods to control eutrophication have received considerable attention and have been intensively tested. In the wake of Chinese carp introduction into European waters great expectations arose regarding the use of silver carp to control eutrophication. Total fish biomass along with progressing eutrophication increases up to a maximum limit and then decreases if eutrophication continues to increase. The chapter reviews the use of phytoplanktivorous fishes to control the excessive development of phytoplankton, which is the most visible and noxious effect of increased eutrophication.
