INTRODUCTION
The Blue Planet
Resources on the land are coming under increasing pressure as the world
population swells and demands for better standards of li: become more
clamorous and urgent. Eroded, worked—out soils, abandoned mines and
irreversibly altered landscape bear witness to their exhaustion. Clearly,
if the pace of this inexorable drain on the land is not to guichen dra—
matically, additional sources offood, water, metals and minerals as
well as less tangible comforts must be found. The oceans are the last
great resource available on Earth. Moreover they have at least one
exceptional property when compared with the land—they are selfrenewing. Terrestrial mineral supplies are being exhausted while those
in the ocean increase; the agricultural yield of the land relies on
intensive care involving such things as the application offertilizers and
other chemicals to restore vigour, whereas the sheries supply food
steadily providing that catches are not greater than the reproductive
capacity ofthesh stocks; and any fresh water removed from the oceans
by evaporation, both man—induced and solar, eventually returns again
to the ocean reservoir. In other words the oceans need never become
worked out and derelict [c'/ee an increasing proportion of the land.
N 0 OTHER planet, as far as we know, has anything resembling an
ocean, but the fact that over seven—tenths of the Earth’s surface is
covered with water has now become a traditional introduction to
most articles on marine topics. The ocean reservoirs hold about
97 per cent of the planet’s stock of water—some 330 million cubic
miles of it spread over an area of 139,440,000 square miles. The
oceans also receive minerals leached or dissolved from the land by
rain and rivets, thus giving sea—water its characteristic salty tang.
The principle constituent is, of course, common salt; there is
enough salt to cover the continents with a layer some 500 feet thick.
î3
The Blue Planet
Resources on the land are coming under increasing pressure as the world
population swells and demands for better standards of li: become more
clamorous and urgent. Eroded, worked—out soils, abandoned mines and
irreversibly altered landscape bear witness to their exhaustion. Clearly,
if the pace of this inexorable drain on the land is not to guichen dra—
matically, additional sources offood, water, metals and minerals as
well as less tangible comforts must be found. The oceans are the last
great resource available on Earth. Moreover they have at least one
exceptional property when compared with the land—they are selfrenewing. Terrestrial mineral supplies are being exhausted while those
in the ocean increase; the agricultural yield of the land relies on
intensive care involving such things as the application offertilizers and
other chemicals to restore vigour, whereas the sheries supply food
steadily providing that catches are not greater than the reproductive
capacity ofthesh stocks; and any fresh water removed from the oceans
by evaporation, both man—induced and solar, eventually returns again
to the ocean reservoir. In other words the oceans need never become
worked out and derelict [c'/ee an increasing proportion of the land.
N 0 OTHER planet, as far as we know, has anything resembling an
ocean, but the fact that over seven—tenths of the Earth’s surface is
covered with water has now become a traditional introduction to
most articles on marine topics. The ocean reservoirs hold about
97 per cent of the planet’s stock of water—some 330 million cubic
miles of it spread over an area of 139,440,000 square miles. The
oceans also receive minerals leached or dissolved from the land by
rain and rivets, thus giving sea—water its characteristic salty tang.
The principle constituent is, of course, common salt; there is
enough salt to cover the continents with a layer some 500 feet thick.
î3