Can nutrients lost to streams and rivers affect downstream receiving waters such as the Gulf of Mexico and Chesapeake Bay?
Nutrients that are lost to streams can be transported downstream to major receiving waters, such as the Gulf of Mexico and Chesapeake Bay, and affect levels of dissolved oxygen and hypoxia, which can harm fish and shellfish that are economically and ecologically important to the Nation. USGS nutrient models, known as SPARROW (http://water.usgs.gov/nawqa/sparrow ) relate in-stream nutrient loads to upstream nutrient sources and watershed characteristics affecting transport and thereby provide information on the delivery of nitrogen and phosphorus from 62,000 stream reaches to the Nation’s major rivers and estuaries. Modeled findings show that yields and delivery to major estuaries are highest from watersheds that are drained by large rivers in which relatively little natural removal occurs.
