Figure 26. Results of controlled rearing tech- 
niques with lake trout. Lower two fish grew 
under normal conditions. 
include pumps, temperature controllers, automatic 
monitoring of nutrients, etc. In a region having 
cheaper labor, the system might be largely a 
manual operation with a minimum of capital 
investment. 
Artificial upwelling techniques, artificial reefs, 
and control of environmental temperatures can 
increase fish production further. As an example, 
the University of Miami has a research grant for 
raising shrimp, using waste heat from power 
generation plants at Turkey Point, Florida to 
control water temperatures. Thermal energy dis- 
sipated from nuclear installations offers a whole 
new field of development, particularly in aquacul- 
ture. The New England lobster population is 
declining becasue long-range climatic cycles have 
reduced water temperatures below the levels favor- 
able to their growth. 
Heat from man-made sources, if properly ap- 
plied, potentially could benefit aquaculture and 
selected fisheries. Basic understanding of how 
waste heat can be used is being investigated in a 
Bureau of Commercial Fisheries project to rear 
mackerel artificially under controlled environ- 
mental conditions (Figure 27). 
The United States can contribute substantially 
to development of new and improved techniques 
in aquaculture by applying its experience and 
competence in such fields as pathology, ecology, 
microbiology, nutrition, genetics, chemistry, and 
engineering. Application of techniques in devel- 
oping countries could aid materially in the war on 
hunger. Immediate benefits to the United States 
would be increased production of food items now 
considered luxuries because of limited supplies. 
VI-160 
a 
EPO ¥ esx. 
Figure 27. Mackerel reared on plankton from 
ocean. Nutrient-rich deep waters brought to 
the sunlit surface support prolific plant life on 
which fish thrive. Waste heat from fossil or nu- 
clear power plants may benefit aquaculture and 
selected fisheries. (Bureau of Commercial 
Fisheries photo) 
Engineering aspects of shellfish farming (partic- 
ularly equipment employed, means for enclosing 
farming areas, and methods for controlling the 
growth environment) need concentrated attention 
for improvement and economy. Very little has 
been accomplished in practical demonstration of 
open sea aquaculture techniques to date. With the 
proper encouragement to industry, the techniques 
needed will be developed, leading to increased 
catches, improved efficiency, and better fulfill- 
ment of needs for fish protein. 
A concept of an open sea aquacultural opera- 
tion is illustrated in Figure 28. 
C. Conclusions 
Aquaculture can make a major contribution to 
the war on hunger, by applying recent scientific 
and technological advances to existing practices or 
by development of new techniques in such fields 
as pathology, genetics, nutrition, ecology, and 
engineering. 
Aquaculture is practiced in the United States to 
various degrees in raising luxury crops or augment- 
ing natural stocks. Aquaculture programs are 
scattered among several groups. Real progress will 
