Exxon Valdez oil spill a number of recommendations, such as changes to the work patterns of Exxon crew in order to address the causes of the accident. In response to the spill, the United States Congress passed the Oil Pollution Act of 1990 (OPA). The legislation included a clause that prohibits any vessel that, after March 22, 1989, has caused an oil spill of more than in any marine area, from operating in Prince William Sound. In April 1998, the company argued in a legal action against the Federal government that the ship should be allowed back into Alaskan waters. Exxon claimed OPA was
Oil tanker shipped by tanker. This amounted to 34.1% of all seaborne trade for that year. In terms of amount carried and distance carried, oil tankers moved 6,487 billion metric-ton-miles of oil in 1970. The United Nations also keeps statistics about oil tanker productivity, stated in terms of metric tons carried per metric ton of deadweight as well as metric-ton-miles of carriage per metric ton of deadweight. In 2005, for each of oil tankers, 6.7 metric tons of cargo was carried. Similarly, each of oil tankers was responsible for 32,400 metric-ton miles of carriage. The main loading ports in 2005 were located