Availability and Efficacy of Ballast Water Treatment Technology: Background and Issue Paper

: Ballast water discharges have historically been a major source of nonindigenous species introductions to marine, estuarine, and freshwater ecosystems in the United States. Aquatic organisms may be discharged when the vessel discharges ballast tanks that contains such species, or when the vessel adds ballast water to tanks that contain such organisms in the residual water or sediment in the tank, and later discharges that mixture. When such...