The enrichment of water, both fresh and saline, by nutrients (especially the compounds of nitrogen and phosphorus) that accelerate the growth of algae and higher forms of plant life and lead to the depletion of oxygen, blockage of sunlight and increasing temperatures. These changes may harm the original ecosystem. Eutrophication may occur naturally or as the result of anthropogenic influences (e.g. water pollution). Eutrophic comes from the Greek word eutrophos meaning well nourished. Eutrophic waters are distinguished from logographic waters, characterised by a nutrient deficiency, and mesotrophic waters with an intermediate level of productivity.