The United States, therefore, has recognized the need 
for interim domestic legislation so that ocean mining 
may proceed. 
The recovery of nodules from the deep seabed 
presents a unique natural resource problem. The con- 
servation principles of protecting the environment 
and providing for the orderly development of the 
resource must be met. In addition, there is another 
principle of recognizing the international nature of 
these resources and creating a mining environment 
consistent with international obligations. This prin- 
ciple adds a unique complexity to this nai-ral re- 
source problem and makes achievement of the other 
principles more difficult. 
Nature and Extent of the Resource 
The origin of the deep-sea deposits of hydrous 
ferromanganese oxides or manganese nodules has 
been under debate for some time. Several ‘theories 
have been cited, including introduction of manganese 
from land drainage and subsequent precipitation on 
the seafloor, introduction from submarine volcanism 
with subsequent precipitation in an oxidizing envir- 
onment, and dissolution from hemipelagic sediments 
under reducing conditions and reprecipitation near 
the oxidizing sediment/ water interfaces.** It is likely 
that any one of these mechanisms may dominate, 
depending on the local environment. A somewhat 
more controversial theory is that nodule growth and 
dissolution is controlled by bacterial action. Both 
theoretical and experimental evidence for this have 
been presented.*” 
The nodules are widespread, but unevenly dis- 
tributed. In some large areas they may cover 100 
percent of the seafloor and in other areas be entirely 
absent. The reported range of concentration varies 
widely, growth rates also vary, and nodule size may 
not be a direct function of age. Mineral content 
apparently correlates with other nodule parameters 
and environmental factors. For example, depth cor- 
relates directly with cobalt and copper content in the 
Pacific.** 
Data available on worldwide distribution of 
manganese nodules and other subsea resources were 
, consolidated into a set of maps and published by the 
US. Geological Survey in 1970 as map I-632. 
| Subsequently, considerable work has been done in 
the northeast equatorial Pacific Ocean under the 
{manganese nodule project of the National Science 
|Foundation and under various academic investiga- 
\ tions under Sea Grant programs. Scripps & Lamont 
®E. Bonatti, “Authigenesis of Minerals—Marine,” in En- 
cyclopedia of Geochemical and Environmental Sciences, S. V. 
Hill (ed.). Volume IV A, 1972, pp. 45-56. 
“H. L. Ehrlich, The Microbiology of Manganese Nodules. 
Final Technical Report, Task No. NR 137-655, Office of Naval 
Research, U.S. Department of Defense, 1970, pp. 1-17. 
“A. M. Ehrlich. Rare Earth Abundances in Manganese 
Nodules. Ph.D. Thesis: Massachusetts Institute of Technology, 
1968, pp. 3-216. 
Doherty laboratories have already participated in this 
research. Detailed prospecting and exploration have 
been made by industrial concerns, both U.S. and 
‘foreign, but this information is generally not in the 
)public domain. 
From a resource standpoint, the depth zones be- 
tween 3,000 and 6,000 meters have the most poten- 
tial. Estimates of resources for the Pacific Ocean 
have been reported by Mero (1965)*° at 1,700 billion 
metric tons, later revised (1967) to 1,500 billion, and 
by Zenkevitch and Skornyakova (1961) at 90 
billion metric tons. Mero’s figures are based on meas- 
urement from 101 photographs and cores and grab 
samples; most of the calculations concerning manga- 
nese nodule tonnages are admittedly speculative 
and have little meaning in an economic sense. More 
data are available now, and compilations of resources 
have been published by others. These reports sug- 
gest that the extent of nodules in the Pacific Ocean is 
about 1,500 billion metric tons. 
Less is known about nodules in other oceans. For 
the purpose of world resource estimates, a total of 
1,700 billion metric tons, as reported by Mero 
(1965) *' and cited by MeKelvey et al. (1969) % 
may be assumed. This estimate includes 1,500 billion 
metric tons in the Pacific, 150 billion metric tons in 
the Indian Ocean, and 50 billion metric tons in the 
Atlantic. Estimates for the Arctic or small ocean 
basins have not been made. 
Data available on the worldwide distribution of 
potential mine sites were summarized in a 1976 
staff study by the Department of Interior’s Ocean 
Mining Administration.** The richest concentrations 
apparently are in the Pacific north of the Equator, 
extending from the Hawaiian Islands to the west 
coast of Mexico, a region about 2,600 miles long 
and 500 miles wide. 
The Bureau_of--Mines~is- developing a comprehen- 
sive computerized data base on nodule location, 
analyses, and sample information; data have been 
entered for more than 5,000 samples from more than 
2,700 stations in the Pacific and Indian Oceans. The 
information is compiled under contracts and grants 
with universities and other oceanographic institu- 
tions, including company data where available. These 
data are being incorporated into a series of mineral 
resource and bathymetric maps to be published. 
Based on these data, nodule units are being identified 
85. L. Mero. The Mineral Resources of the Sea. New York: 
Elsevier Publishing Company, 1965, p. 312. 
N,. Zenkevitch and N. S. Skornyakova. “Iron and Manga- 
nese on the Ocean Bottom” Natura (U.S.S.R.), 1961, p. 47-50. 
"J. L. Mero, op. cit. note 89. 
"U.S. Department of the Interior, Geological Survey, Sub- 
sea Mineral Resources and Problems Related to Their Develop- 
ment, by V. E. McKelvey, J. I. Tracy, G. E. Stoertz, and J. G. 
Vedder, USGS Circular 619. Washington, D.C., Government 
Printing Office, 1969. 
"U.S. Department of the Interior, Ocean Mining Administra- 
tion. Manganese Nodule Resources and Mine Site Availability, 
by A. Holser, Professional Staff Study, August 1976. 
VI-24 
