They also contaminate the sediments that need to be dredged from the harbor to accommodate shipping needs. We have made enormous progress in the past 25 years in addressing the most egregious environmental threats to these waters. Controlling discharges from combined sewer overflows by implementing management practices consistent with the EPA's National CSO Control Policy. Controlling nutrient loading, as necessary, to alleviate low dissolved oxygen conditions, for example, using low-cost nitrogen removal methods at municipal sewage treatment plants. Developing non-point source management programs including control of sediment inputs in, for example, the Whippany River Basin in New Jersey.
Estuaries are special water bodies that are open connections to the sea.
Because of the unique nature of estuaries, which comprise of saltwater and freshwater, they are ever changing and therefore are among the most productive of all ecosystems, with 80 percent of all fish and shellfish using them for primary habitats, spawning or nursing grounds.