Definitions for "Ballast Water"
Water carried in designated ballast water tanks (segregated tanks) or cargo tanks (non-segregated tanks) to control draft, trim, stresses, and stability
water carried in special tanks (ballast tanks) of ships for insuring proper stability, especially needed when carrying less than a full load of freight. Ballast water pumped into the ballast tanks in a freshwater port could carry freshwater organisms to a new port if pumped out when a new cargo is loaded. This is the mechanism by which it is believed that zebra mussels were carried to North America. Ocean-going ships entering North America are now required to exchange freshwater ballast for ocean water to prevent introductions of other exotic organisms by this means.
is water (which often contains aquatic life) that is pumped on board a ship or vessel to ensure stability and balance during a voyage. It may be discharged untreated at points all across the globe.