Source: American Association of Port Authorities.

Throughput of the World's Major Ports, 2006 (in millions of metric tons)

A port throughput is linked to a variety of local and regional industrial activities. For instance, the largest ports in the world are all gateways to massive industrial regions. The position of Rotterdam as the world's largest port was unparalleled for decades, a rank it held until 2000. Then it was overtaken by Shanghai and Singapore; almost all of the word's major ports are now in Pacific Asia. They main factor behind this growth are linked with export-oriented strategies which concomitantly involve in increase in export throughputs, but also imports of parts, energy and raw materials to supply the urbanization and industrialization. However, comparing ports on a tonnage basis requires caution as it does not indicate the value of the cargo.