The St. Lawrence Seaway opened in 1959 to great fanfare. The system of canals connecting the Atlantic Ocean and the five Great Lakes cut a lucrative international trade route through the heartland and gave the United States a refuge and staging ground for ships and submarines in case of war with the Soviet Union.
No one expected the seaway to become the key player in a different war, the invasion of non-native aquatic species into the Great Lakes, which has dramatically altered ecosystems and costs hundreds of millions of dollars a year. About a third of the 186 invasive species in the Great Lakes are thought to have entered on oceangoing ships in the ballast water they take on for stabilization when carrying little or no cargo.
Zebra and quagga mussels from the Black Sea clog intake structures for municipal water systems and power plants. The mussels also gobble plankton so voraciously that little is left for other organisms. Round gobies and other invasive fish beat out native fish for food supplies, harming the lucrative commercial and sport fishing industries. Ballast is even blamed for the emergence of viral hemorrhagic septicemia, often called "fish ebola," resulting in large fish kills in the past several years.
No one expected the seaway to become the key player in a different war, the invasion of non-native aquatic species into the Great Lakes, which has dramatically altered ecosystems and costs hundreds of millions of dollars a year. About a third of the 186 invasive species in the Great Lakes are thought to have entered on oceangoing ships in the ballast water they take on for stabilization when carrying little or no cargo.
Zebra and quagga mussels from the Black Sea clog intake structures for municipal water systems and power plants. The mussels also gobble plankton so voraciously that little is left for other organisms. Round gobies and other invasive fish beat out native fish for food supplies, harming the lucrative commercial and sport fishing industries. Ballast is even blamed for the emergence of viral hemorrhagic septicemia, often called "fish ebola," resulting in large fish kills in the past several years.


