BUREAU OF FISHERIES 111 



percent in volume and 7 percent in value as compared with the catch 

 in the previous year. The Lakes fisheries of the United States gave 

 employment to 5,623 fishermen in 1936. 



Misdsfiippi River and trtbidaries. — No complete survey of the com- 

 mercial fisheries of the Mississippi River and tributaries was made for 

 1936. The catch of Lake Pepin and Lake Keokuk, and the Mississippi 

 Kiver between the two lakes, in 1936, amounted to 8,181,000 pounds, 

 vahied at $378,000, an increase of 22 percent in volume and 34 percent 

 in value as compared with the catch in these waters during 1935. 



MANUFACTXTKED PRODUCTS OF THE UNITED STATEiS AND ALASKA, CALENDAR YEAR 1936 



Fresh and frozen, packaged -fishery products. — Based on data for 

 1936, except in the case of packaged sliellfish in the New England and 

 Middle Atlantic States, wliich data are for 1935, the domestic produc- 

 tion of fresh and frozen packaged fishery products amounted to 202,- 

 396,000 pounds, valued at $26,895,000. Important commodities in this 

 grou]:) were fresh-shucked oysters, 6,758,000 gallons, valued at $9,249,- 

 000; packaged haddock, 41,187,000 pounds, valued at $4,266,000; and 

 fresh-cooked crab meat, 7,095,000 pounds, valued at $2,535,000. 



Frozen products. — In 1936 the production of frozen fishery products 

 amounted to 179,274,000 pounds, estimated to be valued at $15,000,000. 

 The volume of the production was 20 percent greater than in 1935. 

 The most important products frozen were groundfish, whiting, halibut, 

 salmon, and mackerel. 



Cured products. — The production of cured fishery products, based 

 en data for 1936 in all sections except the New England and Middle 

 Atlantic States, which are for 1935, and the Mississippi River and its 

 tributaries, which are for 1931, amounted to 116,311,000 pounds, valued 

 at $15,616,000. Important products in this group were smoked 

 salmon, 8,753,000 pounds, valued at $2,656,000; mild-cured salmon, 

 11.550,000 pounds, valued at $2,245,000; and salted boneless cod, 7,951,- 

 000 pounds, valued at $1,492,000. 



C anned fishery products. — Canned fishery products produced in 1936 

 amounted to 794,707,000 pounds, valued at $94,564,000, an increase of 

 18 percent in volume and 26 percent in value, as compared with 1935. 

 Canned salmon was the most important item, accounting for 430,- 

 328,000 pounds, valued at $50,061,000. Other leading canned fishery 

 products were tuna and tunalike fishes, sardines, shrimp, mackerel, 

 clam products, and oysters. 



Byproducts. — Fishery byproducts produced in 1936 were valued at 

 $34,976,000, an increase of 17 percent as compared with the previous 

 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 1937, studies in 

 this field included a further development of electrometric tests for the 

 freshness of fish and their practical or commercial application, studies 

 of rancidity in fish, of lactic acid as a possible index of decomposition 

 in frozen fish, of identification of canned salmon, of changes in the 

 composition of pink salmon, and of tlie canning of aquatic products. 

 Much interest was shown by the industry dui-ing the ]:)ast year in the 



