Home | Feature Archive

Nutrients and their delivery to the Chesapeake Bay

The Chesapeake Bay has been adversely impacted by an overabundance of nutrients and sediment and was listed as an impaired water body under the Clean Water Act. The Chesapeake Bay Program (CBP) is attempting to reduce nutrient and sediment loadings to Bay to meet criteria for dissolved oxygen, chlorophyll, and water clarity by the year 2010. The USGS is providing critical science to help the CBP formulate and assess the effectiveness of tributary strategies to reduce nutrients and sediment. The USGS is

1. enhancing analysis and predictive tools to relate nutrient sources to loads,
2. expanding monitoring of the rivers in the watershed,
3. enhancing trend analysis and understanding the factors relating nutrient sources to trends,
4. documenting the influence of ground water on nitrogen movement, and
5. conducting studies of nutrient cycling.

The USGS is working on two primary predictive tools, the CBP Phase V watershed model and the SPARROW model of the Bay watershed. These predictive tools provide complimentary information to help States and local governments formulate the tributary strategies. More information can be found at: http://md.water.usgs.gov/gis/chesbay/SPARROW.htm

Expanding monitoring of the rivers in the watershed will help assess the effectiveness of previous and new tributary strategies. The USGS has been measuring the concentration and loads of nutrients in the major rivers entering the Bay through the river-input monitoring project: http://va.water.usgs.gov/chesbay/RIMP/index.html

The trends in nutrients, and understanding relation of nutrient sources to trends, are being addressed in a current project by the USGS. The influence of ground water on nutrient trends was recently summarized in a report and fact sheet “The Influence of Ground Water on Nitrogen Delivery to the Chesapeake Bay, Online Publication - FS-091-03”:

Studies of nutrient cycling include addressing the affect of antibiotics on bacteria that cycle nutrients and through the National Water-Quality Assessment (NAWQA) Program Delmarva-Potomac Study Unit Nutrient Enrichment Effect Studies in the Coastal Plain.

The March issue of the Bay Journal had a large feature section on nutrients.

More information about the USGS and nutrients can be found on our Water Quality page, Nutrients section and on the Publications page by searching the References site.

Visit the USGS Chesapeake Bay Activities Feature Archive