MINERALS IN SEA MAY NOT BE ECONOMIC

Press, Volume CVIII, Issue 31754, 10 August 1968, Page 5

MINERALS IN SEA MAY NOT BE ECONOMIC

(By

ROBERT C. COWEN,

natural science editor oj the ’’Christian

Science Monitor”) A geologist, Mr K. O. Emery is sceptical about the riches men can hope to win from the sea. He calls much of the current talks of mining the sea floor “press agents’ visions.” At Woods Hole Oceanographic Institution (Massachusetts) he has made extensive studies of sea bed resources. His conclusions have, for several years, run counter to a tide of optimistic forecasts of mineable wealth coming from many oceanographers, politicians, and industrialists.

Discussing this during a recent meeting of Woods Hole Associates, he explained why he remains a sceptic.

Offshore gas and oil already are a big resource. They should grow rapidly in importance over the next decade. But, beyond these two money makers. Dr Emery points out that the sea yields relatively few minerals today. While some diamonds are mined off Africa, the production cannot begin to match that from sources on land. Shells, sulphur, and sand and gravel also come from the sea. Taken together Dr Emery notes that all such minerals make a small contribution to world supplies today. The difficulties of recovering them, in his judgment, cast doubt on their potential contribution tomorrow.

There are the much-discus-sed manganese nodules, for example. These form as lumps around objects such as sharks’ teeth. A deposit rich in manganese slowly precipitates from sea water to build up around these nuclei. Sometimes, it forms in layers on the sea bottom itself where the bed has no covering sediments.

The nodules lie thickly scattered in many deep-sea areas. Off the Blake Plateau, which borders the United States south-eastern seaboard, manganese-rich layers lie exposed in only 1000 feet of water.

Not Economical Many forecasts of the sea's riches envision mining the nodules for manganese or for the copper, nickel, and cobalt they also contain. However. Dr Emery said,

the manganese is hard to extract. It wouldn’t be worth the cost of recovery today. He doubts if it will be economically attractive for a long time. As for the other metals, present in low concentrations, he said there still are better deposits on land.

He added that several companies have tried mining techniques off Blake Plateau, where the manganese deposits are relatively easy to reach. But the manganese is not as pure there as in the nodules As far as he knows, all of the companies who have tried the mining have given it up. Then there are phosphorites. The sea bed has billions of tons of this material which makes good fertiliser. This, too, seems a potentially valuable resource.

He acknowledged that sometimes the deposits lie off the shores of countries that are short of this kind of fertiliser. They could use it if they could afford to get it.-But, he noted, these countries usually cannot meet such expense. Valid Warning Dr Emery has given these arguments many times before. They haven’t dampened the general optimism that envisions eventually mining great wealth from the sea.

Dr Emery said he goes on repeating his position because his own continuing study convinces him it is valid. He feels it is important in the continuing discussion of how to share the sea’s resources among nations that the public realise most predictions of mineral wealth from the sea may be chimeras.