Cultural Eutrophication

Abstract The phrase “cultural eutrophication” (=cultural enrichment) is becoming widely used to denote organic pollution resulting from human activities. Humans, through their various cultural activities, have greatly accelerated this process in thousands of lakes around the globe. Cultural or anthropogenic “eutrophication” is water pollution caused by excessive plant nutrients. Increased productivity in an aquatic system sometimes can be beneficial. Fish and other desirable species may grow faster, providing a welcome food source (1). Eutrophication produces “blooms” of algae or thick growths of aquatic plants stimulated by elevated phosphorus or nitrogen levels. There has been some uncertainty as to whether algal blooms result from increased concentrations of nitrate or phosphate or from some other cause. It is now commonly accepted that algal growth in fresh waters is generally restricted by phosphate concentrations, whereas in marine waters, it is restricted by nitrate concentration (2). In freshwaters, the nitrate concentration might, however, influence the kinds of algae that grow, some of which taint in drinking water or are toxic to animals.