Describing a body of water (e.g. a lake) with an abundant supply of nutrients and a high rate of formation of organic matter by photosynthesis. Pollution of a lake by sewage or fertilizers renders it eutrophic (a process called eutrophication). This stimulates excessive growth of algae (see algal bloom); the death and subsequent decomposition of these increases the biochemical oxygen demand and thus depletes the oxygen content of the lake, resulting in the death of the lake’s fish and other animals. Compare dystrophic; mesotrophic; oligotrophic.