Changes in Mississippi River Water Quality this CenturyImplications for coastal food webs

摘要: Water quality in streams, rivers, lakes, and coastal waters may change when watersheds are modified by alterations vegetation, sediment balance, or fertilizer use after, for example, industrialization the conversion of forests grasslands to farms cities (e.g., Aber et al. 1989, Borman Likens 1979, Schlosser Karr 1981, White 1981). Quantification these watershed/water-quality relationships is important understanding consequences existing potential watershed changes as well possibilities preventive remedial action. There two recent examples improved contributing public policy discussions. Knowledge role phosphorus structuring freshwater phytoplankton communities led regulation detergents sewage-treatment strategies Schindler 1974, 1977, 1978, Vollenweider Kerekes 1980). Recognition that acid precipitation results from coal-fired power plants harmful lakes smokestack emission standards 1982, Ruess Johnson 1986). Water-quality coincident with