FISHERY INDUSTRIES OF THE UNITED STATES, 1922. 7 



as net preservatives. These data are published in a separate docu- 

 ment.^ 



Perhaps the most significant result of the work was the discovery of 

 the valuable properties of copper oleate as a net preservative. This 

 substance, from its fundamental properties, seemed to offer good 

 prospects as a net preservative and was accordingly included in vari- 

 ous combinations among the substances tested. It was dissolved in 

 gasoline or benzol and the twine was dipped in the solution. By test- 

 ing before and after various periods of exposure it was found to pre- 

 serve lines well, to reduce if not entirely prevent fouling by barnacles 

 and the like, and in addition to these two fundamental essential prop- 

 erties, to affect stiffness and increase weight of twine very little. It 

 does not dimiuish mechanical wearing quality of twine, as many other 

 preservatives do, does not shrmk the line appreciably, and is not very 

 expensive or difficult to apply. Announcement of the results was 

 made at the annual meetings of the American Fisheries Society at 

 Madison, Wis., September 6, 1922, and the United States Fisheries 

 Association at Atlantic City, N. J., September 22, 1922, followed by 

 short publications of summaries of results in the fishery trade journals. 

 The interest of the fishing industry in this work was immecliate and 

 widespread. The next step in the investigation was a practical trial 

 of the material by several fishermen in different localities, to whom 

 the bureau supplied a sufficient amount of copper oleate for the tests, 

 with directions for use. About 700 pounds of copper oleate were made 

 for this purpose in the Fisherj^ Products Laboratory. 



Meanwhile, several companies entered into the manufacture of cop- 

 per oleate for a fish-net preservative, and much of it has been sold 

 and is in use by fishermen. The 1923 season will probably be con- 

 clusive of its actual value. Further experiments are in progress on a 

 still larger scale, including several other proposed preservatives and 

 also combinations of copper oleate designed to make it more suitable 

 for use in fresh water, since earlier experiments were less satisfactory 

 in fresh water than in salt water. 



CANNING SARDINES. 



By far the greater part of sardines canned in California are packed 

 in sauce, principally tomato. The usual procedure is to clean the fish, 

 brine, dry, fry in oil, cool and pack the fish, exhaust, seal, and retort 

 the cans. 



In this process, the most objectionable feature is the frying in oil. 

 This part of the process was studied at the San Pedro (Calif.) labora- 

 tory in 1921, and the results of that investigation were discussed in the 

 division's report for that year. The results have since been pub- 

 lished by the California Fish and Game Commission.^ The principal 

 conclusion arrived at in that work was that the fry bath is responsible 

 for the existence in canned sardines of a rancid, indigestible oil, which 

 greatly detracts from the quality of the goods. Since the primary 

 purpose of the fry bath is to cook out the excess water from the fish 

 before canning,* the problem resolved itself into one of removing the 



» Taylor, Harden F., and Arthur W. Wells: Properties and Values of Certain Fish-net Preservatives. 

 Appendix I, Report of the U. S. Commissioner of Fisheries for 1923, Document 947, 69 pp., 35 figs. Wash- 

 ington, 1923. 



< Beard, Harry R.: Changes in Oil used for Fryinp Sardine, State of Califoniia, Fish and Game Commis- 

 sion Circular No. 1, March, 1922, 8 pp. 



