Oceans

Ocean Resources and Uses

Fish have been an important food source since prehistoric times. Most fish are caught along the continental shelf and shoreline, although deep-sea fishing is also popular. Commercial fishing increased substantially after World War II due to population growth, increased demand for food, and technological developments. Whales have been hunted for centuries, not just for food but also for the blubber used to make oil and soap. Other aquatic food products include shellfish, oysters, clams, algae and kelp, and sea salt. The removal of salt from seawater, a process known as desalination, can provide potable water and irrigation water but is currently a small and costly operation.

The oceans have also historically been used in commercial and military activities. In early history, ocean shipping was easier and more reliable than bulky land transportation over uncertain routes and allowed empires such as Rome to gain economic and political power through the control of such waterborne trade routes. Early developments in shipbuilding and navigation made transoceanic voyages possible, allowing explorers and settlers to travel to the New World and other uncharted destinations. As European nations built colonial empires, beginning in the 16th century, ocean shipping facilitated the development of mercantilist trade as colonies delivered raw materials to Europe and purchased European manufactured goods.

The industrial revolution of the 19th century led to the development of iron and steel ships fueled by steam power, and the 20th century saw the rise of diesel-powered tankers, container ships, and bulk carriers that allowed for ever faster and [Page 1258]safer shipping of larger quantities of international trade goods. Modern merchant ships, rather than their speedier aircraft counterparts, transport over 90% of global cargo because of lower costs, increased efficiency and reliability, and the size of cargos that can be hauled overseas.

Humans have also extracted valuable energy sources from the ocean floors and waters. The fossils of dead animals and plants that settled on the ocean floor in time converted to fossil fuels such as oil and natural gas. Oil rigs anchored to the sea floor extract this valuable resource, which is then pumped ashore through pipelines. The oceans also contain valuable mineral and metal deposits, such as manganese, iron, nickel, copper, and sulfur, although many lie deep beneath the ocean floor and their potential extraction is both costly and controversial. Ocean thermal energy conversion plants extract the solar energy absorbed by surface waters, and similar methods for extracting energy from ocean movements such as currents, waves, and tides are under development.

...