Ballast water is essential for safe shipping operations. A ship’s ballast water system allows it to pump water in and out of large tanks to counterweight for a change in cargo load providing stability and maneuverability when not carrying enough weight to face rough seas.
Ballast water of commercial ships is the leading vector for aquatic invasive species into and within the Great Lakes of North America. Ballast water is pumped into ballast tanks when a ship has delivered cargo to a port and is then transported and released at the next port where the ship picks up more cargo. In some cases, ship’s ballast water contains waters from multiple ports.
The introduction of nonnative marine organisms and other similar pathogens has caused major damage to many of the worlds’ coastal regions and bio-diversities over the years. Examples of such organisms are Golden Mussels, Zebra Mussels, North American Comb Jellyfish, the Cladoceran Water Flea, and the North Pacific Seastar.
The Great Lakes region benefits from a robust waterborne transportation system, but the same system has been the conduit of devastating aquatic invasive species introductions. Damage to the Great Lakes from invasive species catalyzed national and international requirements on ships to treat ballast water. Indicative monitoring of ballast water to verify the effectiveness of treatment will be a critical component in determining these programs’ success in protecting the Great Lakes.