Between 1996 and 2000, there were over 8000 reported oil spills in U.S. navigable waters annually; in 2000, the total volume of oil spilled by vessels was approximately 1 million gallons (Gibson, 2001).
Spills of hazardous materials from maritime vessels are one of the most publicized impacts of water-based transportation.
An example is the 11-million gallon crude oil spill by the Exxon Valdez oil tanker in 1989, which resulted in severe water pollution and tremendous loss of marine life (Miller and Tyler, 1990)