eutrophic 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.

eutrophic Originally applied to nutrient-rich waters with high primary productivity but now also applied to soils. Typically, eutrophic lakes are shallow, with a dense plankton population and well-developed littoral vegetation. The high organic content may mean that in summer, when there is stagnation resulting from thermal stratification, oxygen supplies in the hypolimnion become limiting for some fish species, e.g. trout. Compare OLIGOTROPHIC.

eutrophic Originally applied to nutrientrich waters with high primary productivity but now also applied to soils. Typically, eutrophic lakes are shallow, with a dense plankton population and well-developed littoral vegetation. The high organic content may mean that in summer, when there is stagnation caused by thermal stratification, oxygen supplies in the hypolimnion become limiting for some fish species (e.g. trout). Compare oligotrophic.

eu·troph·ic / yoōˈträfik; -trō-/ • adj. Ecol. (of a lake or other body of water) rich in nutrients and so supporting a dense plant population, the decomposition of which kills animal life by depriving it of oxygen.

eutrophic Applied to nutrient-rich waters with high primary productivity. Compare OLIGOTROPHIC.