96 RHPORT OF 'THE SECRETARY OF COMMERCE 
valued at $15,691,000. Important products in this group were smoked 
salmon, 8,822,000 pounds, valued at $2,674,000; mild-cured salmon, 
10,571,000 pounds, valued at $2,148,000; and boneless cod, 8,678,000 
pounds, valued at $1,535,000. 
Canned fishery products —Canned fishery products produced in 
1935 amounted to 672,756,000 pounds, valued at $74,999,000—a de- 
crease of 4 percent in volume and 6 percent in value as compared with 
1934. Canned salmon alone amounted to 289,339,000 pounds, valued 
at $32,475,000. Other important canned products were tuna and tuna- 
like fishes, sardines, mackerel, shrimp, clam products, and oysters. 
Byproducts—During 1935 the value of the production of fishery 
byproducts amounted to $29,520,000—an increase of 30 percent as 
compared with the preceding year. Important products in this group 
were marine-animal oils and meals, and aquatic-shell products. 
TECHNOLOGICAL INVESTIGATIONS 
Preservation of fishery products for food—During 1936, major 
projects in this field covered a continuation of the development of 
electrometric tests for the freshness of fish, studies of rancidity in 
fish, variation in the fat content of halibut, identification of canned 
salmon, development of methods for canning various fishery products, 
and studies of the low temperature preservation of Pacific oysters. 
The problem of preventing or retarding the development of rancidity 
of the oil or fat in fish has always been a serious one and one which 
is very difficult of practical solution. However, during the past year, 
the Bureau’s technologists continued a study of the possible applica- 
tion of various harmless antioxidants for preventing or retarding 
this rancidity and among those antioxidants or inhibitors of oxida- 
tion tested were the cereal flours, such as oats, rice, etc. Studies of 
the chemical and physical characteristics of various salmon oils pre- 
pared from cannery trimmings indicate that the variation in the char- 
acteristics of these oils may provide a method for checking the iden- 
tity of the species of salmon after it is canned. Experiments in the 
development of methods for canning various fishery products, both in 
the home and for application on a commercial scale, have aroused 
considerable interest. In fact, in some instances, widespread use is 
being made of methods already published by the Bureau. 
Bacteriological studies—The Bureau’s bacteriological studies have 
been closely correlated with other investigations of the technological 
staff, as many of these problems require a knowledge of the action of 
bacteria. These bacteriological investigations have included examina- 
tions of the experimental packs of canned fishery products to deter- 
mine which processes produce sterility; bacterial counts on samples 
used in experiments on freezing oysters; studies of the role of bae- 
teria in the different types of decomposition or spoilage described in 
preceding paragraphs, with special reference to the studies on mack- 
erel; determinations of the effectiveness of formaldehyde and other 
chemical preservatives in preventing or retarding the development of 
bacterial spoilage in fishery byproducts; and other miscellaneous bac- 
terial control problems. , 
Pharmacological, studies—The pharmacology of fishery products is 
a comparatively new investigational field, and interest in it has been 
greatly stimulated by discussions in scientific journals and in the press 
