pluses produced by the removal of sulfur from fossil 
fuels. 
Other marine resources with economic potential 
now or in the perceivable future are magnesium, 
which is extracted from seawater, and varieties of 
seaweed such as kelp. These marine plants are har- 
vested and processed into commercial products. Cul- 
fivation of kelp has also been proposed to acquire 
fuel for use in generating energy, but its prospects for 
energy production on an economic basis are ques- 
tionable. 
In addition to these resources, high expectations 
in the 1960s led to Federal efforts to obtain fresh- 
water from brine and ocean waters and to mine gold 
and other heavy elements in subsea placer deposits. 
These efforts were discontinued, and there is no rea- 
son to believe they will be resumed in the foresee- 
able future. 
Ocean Uses 
Only a part of the U.S. stake in the ocean is bound 
to harvesting its resource wealth. Although the 
United States is not an insular nation, as England 
and Japan are, the United States is more dependent 
today on the oceans for defense, trade, recreation, 
and other national needs. 
National Defense 
A substantial ingredient of the U.S. stake in the 
ocean is the defense it provides as a natural barrier 
to military invasion. However, the effectiveness of 
the ocean in this role depends on the maintenance 
of a strong naval posture. Today, naval power de- 
pends on advances in ocean science and technology, 
many of which yield economic or social benefits in 
addition to supporting defense requirements. The 
Navy has, therefore, become a major contributor to 
the development of a number of ocean activities, 
civil as well as military. 
Merchant Shipping 
The role of merchant shipping in the U.S. econ- 
omy is demonstrated by the magnitude of its water- 
borne trade. In 1976 U.S. waterborne foreign export 
commerce consisted of 282.8 million short tons 
valued at more than $64 billion. In the same year, 
waterborne imports totaled 517.5 million short tons 
with a value of almost $81 billion. In addition to 
this foreign trade traffic, 232.5 million short tons 
were shipped coastwise in domestic ocean_waters 
during 1976 and another 140.3 million short tons 
were shipped in Great Lakes waters. 
Petroleum shipping has become especially im- 
portant as dependence _on overseas energy sources 
has increased. Furthermore, a large portion of coast- 
wise shipping also consists of petroleum transporta- 
tion, and the prominence ,of domestic petroleum 
shipping is likely to grow as distribution require- 
ments continue to expand. 
A number of projections indicate that foreign 
trade will continue to grow in response to national 
and international economic pressures. Currently, 
however, only about 5 percent of U.S. foreign trade 
is_shipped_in U.S-flag carriers. This has aroused 
concern about our ability to meet our shipping re- 
quirements in the event of another major war. This 
concern, in turn, has prompted efforts to increase 
the capacity and efficiency of our merchant fleet, but 
it now _appears unlikely, with continued growth in 
U.S._trade, that the U.S. fleet will be able to carry 
a significantly higher percentage of the tion's 
foreign commerce in the foreseeable future. 
Di SORUNET CE Ue Olesccd eee 
Recreation 
The U.S. population in 1976 had increased by 
some 40 percent since 1950. Over the same period of 
time, the constant dollar value of the gross national 
product increased over 137 percent and median 
family income increased over 90 percent, also in 
constant dollars. These trends, combined with in- 
creasing leisure time and greater mobility, have 
resulted in an accelerating growth in outdoor recrea- 
tional activity, much of it along the seaboard and 
the shores of the Great Lakes. 
Thirty of the 50 States border the oceans or 
Great Lakes. In 1970, about 85.5 million people or 
42 percent of the total population lived within easy 
communting distance cf the oceans or Great Lakes. 
This population distribution generates a wide-ranging 
recreational use of shoreline areas and coastal waters 
by coastal residents, to which must be added the 
activities of vacationers from inland areas. These 
activities have a high personal value for those in- 
volved, and major economic value for coastal com- 
munities and the recreation industry. 
Estimates of expenditures for marine-related rec- 
reation are diflicult because data on recreational 
expenditures do not distinguish between coastal and 
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