the United States has relied on foreign oil imports 
to maké up the shortfall in domestic supplies. 
In 1977, 4.2 billion barrels were imported at a 
cost of $42.1 billion; natural gas and ethane imports 
cost an additional $1.9 billion. One means of reduc- 
ing the rise in these balance of payments deficits is 
increased domestic production of oil and natural 
gas while alternative energy sources are being devel- 
oped. Imports now provide about half of U.S. petro- 
leum consumption; therefore, using the untapped 
oil and gas reserves of the U.S. continental shelves, 
which are the major new domestic source, has as- 
sumed a new urgency. 
U.S. Geological Survey (USGS) figures show that 
1976 total oil production from the U.S. continental 
shelves was 462.9 million barrels, 32 percent of it 
from State lands and 68 percent from the Outer 
Continental Shelf (OCS). Offshore natural gas pro- 
duction in 1976 was 4.296 trillion cubic feet, 16 per- 
cent from State lands and 84 percent from the shelf. 
To increase OCS oil and gas production, the De- 
partment of the Interior has accelerated its “Offshore 
leasing schedule. The latest official estimates of OCS 
reserves, released in December 1974, placed demon- 
strated and measured offshore oil reserves at 3.2 
billion barrels, with another 3 billion in inferred 
reserves. At that time, the USGS estimated there was 
a 95 percent probability of 10 billion barrels in un- 
discovered recoverable offshore reserves and a 5 
percent probability of up to 49 billion barrels. The 
value of offshore natural gas in demonstrated and 
measured reserves was stated as 36 trillion cubic 
feet with another 67 trillion cubic feet contained in 
inferred reserves. Undiscovered offshore gas re- 
serves were estimated as 0.42 trillion cubic feet, 95 
percent probable, and 181 trillion cubic feet, 5 per- 
cent probable. An updated estimate is to be released 
in 1978. 
Manganese Nodules 
The greatest potential for the development of ma- 
rine hard minerals is provided by manganese nodules 
on the deep-sea bottom. These nodules contain four 
principal minerals: manganese, nickel, copper, and 
cobalt. The most promising nodule beds appear to 
be within a belt on the floor ‘of the North Pacific. 
The quantity of nodules in this belt, rich in copper 
and nickel, has been estimated by the National Acad- 
emy of Sciences at 15 billion tons.* 
In 1976 the world production of primary nickel 
was 920,000 short tons. The United States used 
159,700 short tons but produced only 13,900. The 
balance was imported, primarily from Canada.° 
World demand for nickel is growing 3.5 percent 
annually. This rate of consumption could result in 
the commencement of economically viable manga- 
nese nodule mining operations in the mid-1980s. 
Periodically the United States imports a percent- 
age of its copper requirements, largely from Chile 
and Peru, but generally copper is not now in short 
supply in this country. Manganese, the major ele- 
ment in ocean bottom nodules, is of interest to the 
Other 
Other ocean resources also have some economic 
potential. Some 1 billion short tons of sand and 
gravel are used annually in the United States for 
construction. Much of this material is derived from 
rivers and streams in various parts of the country. 
Because of the costs of transportation, it is normally 
used in the local area. Small amounts have been ob- 
4 National Academy of Sciences. Mineral Resources and the 
Environment. Washington, D.C., 1975, p. 141. 
> Department of the Interior, Bureau of Mines. Nickel 1977. 
MCP-4, July 1977. : 
Ii-3 
steel industry. The United States used 12.8 million 
short tons in 1976, but produced only 50,000 short 
tons. Most imports came from South Africa and 
Gabon.® Cobalt is used in small quantities in the 
United States, but is vital to the steel industry. Vir- 
tually all cobalt is recovered as a byproduct of cop- 
per or nickel. There is no domestic primary produc- 
tion of cobalt. In 1976 the United States imported 
16.5 million pounds of the mineral, most of which 
comes from Zaire and Zambia.’ 
Four international consortia, each including U.S. 
firms, have been formed to begin deep-ocean mining 
‘operations. These consortia have invested $30 mil- 
lion to $50 million each in research and development 
to improve mining. technology. Environmental impact 
assessment work has begun, and additional local 
assessments can be made as sites are chosen. One 
major impediment to development remains: the reso- 
lution of law-of-the-sea_q sea questions concerning juris- 
diction over operations in the deep ocean “outside 
national | jurisdiction. \ MONE Miata ehe GF 
\ 
Resources 
tained from offshore sources, often for use in beach 
replenishment. Offshore sand and gravel mining may 
be of some importance in future marine develop- 
ment. There are sulfur deposits off the coast of 
Louisiana, but their economic value has been dimin- 
ished considerably as the result of large sulfur sur- 
* Department of the Interior, Bureau of Mines, Manganese 
1977. MCP-7, October 1977. 
7 Department of the Interior, Bureau of Mines, Cobalt 1977. 
MCP-5, July 1977. 
