FISHERY TISTDUSTTtlKS OF THE UNITED STATES, 1!>21. 11 



find the number of differing processes employed approximating the 

 nimiber of plants operated. Products, time, labor, and capital have 

 been wasted through ignorance and for lack both of the development 

 of standard methods that will yield high quality products and of 

 specific information as to the best and most economical procedure. 



The annual losses in other sections, as the New England district, 

 resulting from rusting of mackerel and other fish and from reddening 

 of cod and related species are heavy. It is important that technolog- 

 ical studies be made of such problems to develop means of preventing 

 or at least minimizing such losses. The bureau is endeavoring to 

 utilize its facilities in this field to the fullest possible degree but is 

 greatly hampered by its inability to obtain and retain the services of a 

 properly trained personnel, because of the inadequacy of the salaries 

 of such positions as have been created. 



PRESERVATION OF FISH NETS. 



A review of the literature on the subject of net preservation has 

 been made and a report issued which includes a discussion of the 

 fundamental principles in the light of chemistry so far as they are 

 known. This report was prepared in nontechnical language in so 

 far as practicable to make it readily understandable and includes such 

 subjects as nature of disintegration of nets, coloring of nets, preserva- 

 tion of nets by tarring materials and by methods not dependent on 

 tarring materials, and references to the literature. 



Following this preliminary work an investigation of the subject has 

 been begun. This includes tests of the relative value of various net 

 preservatives, including some in commercial use, also tests to de- 

 termine the increase in weight of the net by addition of the preserva- 

 tive, slu'inkage, breaking strength, wearing quality, etc. Treated 

 lines are being used by actual fishermen as one phase of wearing tests. 

 In addition efforts are being made to effect improvements in the 

 preservatives used and in the methods of their application. 



BRINE FREEZING OF FISH. 



Although the work in this field was seriously interfered with during 

 a considerable part of the year progress has been made. A paper 

 reviewing the present status of brine freezing was prepared by the 

 chief technologist and issued for the information of the trade. This 

 emphasizes the need of giving more attention to improving methods 

 of freezing and storage and less to types of machinery; discusses the 

 shorter time required to freeze fish in brine than in air, the non- 

 evaporation of moisture from the fish during the brine freezing, the 

 bright luster of the brine-frozen fish, and the pliability of fins and 

 tail; and presents evidence that defrosted brine-irozen fish are firmer 

 and may oe held satisfactorily for a considerable time and that such 

 fish may be frozen again. Mention of the difficulties of glazing brine- 

 frozen fish is also made, and methods by which such fish may be prop- 

 erly glazed are given. It is stated that the most important aspect of 

 brine freezing awaiting development is its practical application on a 

 large scale. It is to this feature that the investigations now in pro- 

 gress are especially directed. 



The conclusions reached by the author are that brine freezing 

 promises to contribute much of value to improvements in the dis- 



