Nitrate from fertilizer is degraded by microbial action in the presence of solid minerals. This helps mitigate the effect of the nitrate, but begins to diminish the solid minerals needed. Will the process be sustainable in the long term?
Overview of interdisciplinary research on the Tampa Bay estuary of the Gulf of Mexico with links to digital library, interactive mapping, reports, posters, water chemistry maps, meetings and conferences, scientist directory, and field trips.
Summary of part of the USGS interdivisional Mississippi Basin Carbon project that will study the changes in climate and the environment through carbon cycle changes recorded in lake sediments in the Upper Mississippi River Basin.
Here we study effects of climate and groundwater on surface-water levels, the hydrological effects on wetland water chemistry, and the combined effects of climate, hydrology, and water chemistry on plant and animal communities of prairie pothole wetlands.
Upcoming interagency study to assess status of ecological conditions, their relationships with contaminants and nutrients, anthropogenic factors affecting these, and develop models that may predict these ecological conditions.
Instrument measures elemental abundance and isotopic ratios in samples as small as a few nanograms. Uses include geochronology, geological thermometry, and trace element geochemistry of geological and biological materials.
USGS operates a low-enriched uranium-fueled, pool-type reactor located at the Denver Federal Center. We use it for analyses of fissile and fissionable isotopes, geochemical analysis, and geochronology.