BUREAU OF FISHERIES 315 
ery industries through the sale of products heretofore wasted, but it 
also has been most valuable to the drug industry. Of outstanding 
importance, however, is the contribution of this work to the health 
of our people by providing an economical and convenient source of 
vitamins A and D. 
It should be pointed out that technological work, through studies 
which promote the greater utilization of domestic aquatic forms and 
through the development of new uses for these commodities, is making 
the people of the United States less dependent upon foreign sources, 
which is vitally important in view of present world conditions. 
Specifically, the technological work of the Bureau during the past 
year has dealt with problems in the preservation of fishery products 
for food, in the manufacture of fishery byproducts, and in the nutritive 
value of aquatic products in general. 
Preservation of fishery products for food—Studies on the preserva- 
tion of fishery products for food are conducted in the fields of chem- 
istry, biology, and engineering. Their purpose is the improvement 
of the quality of fishery food products; the development of scientific 
tests for judging the quality of fishery products; the development of 
methods for further improving sanitary conditions in fish-packing 
plants; and the development of additional fresh, frozen, cured, and 
canned fish foods. During the past year there were many requests 
for research on problems of this type. This is indicative of the desire 
of the fishery industry to place on the market food products which 
will meet the most exacting requirements as to quality and wholesome- 
ness, and to make the most effective use of the fishery harvest. Not 
only has the fishery industry been instrumental in having these studies 
conducted, but it has been quick to adapt to commercial practice many 
of the recommendations resulting from this work. 
Manufacture of fishery byproducts.—Investigations in the manu- 
facture of fishery byproducts have been particularly concentrated on 
the economic utilization of salmon cannery trimmings and fish livers 
and visceral organs; the preparation of fish meals of improved nutri- 
tive value; the problems of the storage of fish meal; oxidation of fat 
in fish meal; and the solubility of fish proteins. 
Nutritive value of aquatic products—Studies on the nutritive value 
of aquatic products have always occupied an important place in the 
fishery technological investigations because the food value of a prod- 
uct ready for marketing is, in most instances, the true yardstick or 
measure of the value of a new method of processing or an improve- 
ment in existing methods in the industry. For example, assuming 
that costs of processing are equal in each case, if a new method of 
manufacturing fish meal or a new method of freezing fish fillets pro- 
