BUREAU OF FISHERIES 151 
the service also operates numerous news-reporting activities in im- 
portant fish-producing areas along our coasts. These reporting activi- 
ties make possible the inclusion of a much wider coverage of news in 
the daily reports of our field offices than would otherwise be possible. 
Periodic market news reports also are prepared and disseminated 
from the Washington office. These include summarized data made 
available through the daily and monthly reports of the field offices as 
well as articles relating to the commercial fisheries and other related 
information. 
TECHNOLOGICAL INVESTIGATIONS 
Preservation of fishery products for food—During 1938 projects 
in this field included 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, of the 
composition of commercial species of fish taken on the Pacific coast, 
and the canning of aquatic products. 
Of particular interest has been the work on lactic acid as a possible 
index of decomposition in frozen fish. It is known that lactic acid 
rises to Aa Maximum content in fish muscle during the rigor of death. 
It has also been shown that the alkaline reaction of fish muscle and 
the accompanying onset of spoilage of the fish follows after the loss 
of muscular rigor. Since spoilage occurs after the lactic acid con- 
tent of the fish muscle reaches a maximum, the determination of 
lactic acid in fish flesh before and during a period of cold storage 
is of value in obtaining direct knowledge of the processes of decom- 
position of fish. 
Information has been obtained regarding the changes in the chem- 
ical composition of pink salmon accompanying the pronounced physi- 
cal change during their spawning migration and while in the com- 
mercial fishery. Additional data have been collected in connection 
with the development of a means for identifying the various species 
of salmon after canning. A survey has been undertaken to determine 
the chemical composition of the principal food fish of the Pacific 
coast, and the wastage occurring during their preparation for market. 
Studies were continued to determine the effectiveness of certain nat- 
ural antioxidants in preventing rancidity in preserved fishery prod- 
ucts and an attempt is being made to develop a simple and accurate 
method for measuring oxidative deterioration in fatty fish. 
Bacteriological studies—During the past year important bacterio- 
logical problems were studies of ultraviolet rays in killing bacteria, 
studies in the handling of fresh oysters, and studies of methods of 
preparing crab meat. 
The studies in the handling of fresh oysters revealed that there 
is a definite relation between the pH in oysters and the bacterial 
count. The experiments showed that the bacterial flora changes with 
the acidity of the oysters and the bacterial count rises as a result of 
the increased acidity of the oysters. It was further discovered that 
excessive washing of oysters with fresh water caused a loss of mineral 
content. ; 
At the request of several members of the crab-meat industry, the 
Bureau assigned a chemist and a bacteriologist to investigate possible 
measures designed to improve the quality of their product. This 
investigation included a survey of the crab-meat packing plants with 
