Many Toxics Program investigations include or focus directly on the occurrence, transport and ecological effects of nutrients in the environment. The major nutrients nitrogen and phosphorus typically are studied; however, this research includes any process or chemicals that enrich or otherwise affect nutrient budgets in natural as well as anthropogenically affected water resources. Nutrients from agricultural, urban, and other sources are included in these investigations. The information presented on this page cuts across lines drawn by individual investigations and projects so that information on the fate and effects of nutrients can be presented in one place.
Investigations and Research Activities
USGS scientist lowering a water-quality sampler into the Iowa River near Marengo, IA, (site ID 05453100). during the 1993 flood of the upper Mississippi River Watershed. The samples were analyzed for nutrients and pesticides.
Average annual nitrate concentrations in selected rivers during 1905-07 and 1980-96 (FS 135-00).
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