India, West Germany and other countries are planning to extract and process polymetallic nodules from the rich areas of Pacific and Indian Oceans. These potato shaped nodules lie at a depth of 5,000 metres and contain 30 to 40 per cent manganese (used in certain steel alloys) and small amounts of other commercially important metals such as nickel and cobalt. It is proposed that a device much like a giant vacuum cleaner be developed to s(uck these nodules up from the bottom of the deep ocean and deliver them through a long pipe to a ship above the mining site. Environmentalists recognize that such seabed mining would probably cause less harm than mining on land. They are concerned, however, that stirring up deep oceanic sediments may generate fine particles which could choke the gills and filtering organs of marine creatures. This activity could also have unknown effects on poorly understood deep sea trophic chains. Surface waters might also be polluted by discharge of sediments from mining ships, floating platforms and island based units.
The seas of the world have been considered an inexhaustible source of food and as having an infinite capacity to absorb and detoxify our wastes. To this has been added, only recently, the urge to use them as a source of industrial raw materials. It is now apparent that these assumptions have their limitations and that the human population, at the current level of technological development has the ability to inflict massive destruction on the seas, just as we have done on land. At present, the seas remain in good condition relative to the land, but we can not afford to permit them to be degraded in future. We must take care to ensure that the potential of oceans is realised without causing them any ecological damage.