18 BULLETIN 150, U. S. DEPAKTMENT OF AGRICULTURE. 



CHARACTER OF WASTE. 



The first waste involved in the canning of salmon to be considered 

 in this discussion is the waste of fish other than salmon taken with 

 them in seines and traps. This varies widely from day to day and 

 with the place and method of fishing. At best it is a matter of great 

 uncertainty. Thus, in a scow load of 30,000 salmon taken from a trap 

 under the observation of the writer, there was an entirely negligible 

 number of fish other than salmon, while from another trap it was 

 recorded that the catch was made up of approximately 50 per cent 

 of salmon and 50 per cent of other fish. Of the salmon about 1 per 

 cent was dog salmon, a slightly larger proportion was humpbacks, 

 10 per cent was cohoes, and the balance, about 88 per cent, was sock- 

 eyes. Among the other fish taken, a number equal to that of the 

 salmon, were trout, tomcod, flounders, and dog fish. Where the pro- 

 portion of fish other than salmon taken in traps is so great, - they are 

 thrown from the scow as fast as brailed into it ; while if the propor- 

 tion be small, they are permitted to remain. When the fish are un- 

 loaded at the cannery these are thrown overboard by the unloaders as 

 encountered, or, frequently, the edible fish are picked out by children 

 or adults from among the laborers around the cannery and are 

 used for food. Aside from the fish so consumed, there is a consider- 

 able number of food fish for which there is no demand, as well as 

 nonedible fish, such as dogfish, which easily could be made available 

 as a supplementary source of material from which to prepare ferti- 

 lizer and oil. However, from the casual observations of a summer 

 spent in and around the salmon canneries and from the answers to 

 casual inquiries regarding the matter, it must be said that as a 

 source of such material the fish other than salmon, taken incidentally 

 in the salmon fisheries, are too uncertain and too variable in amount 

 to be given very serious consideration. Undoubtedly, in the aggre- 

 gate they form a considerable supply, and a large part of it could 

 be made available for fertilizer manufacture. But in view of the 

 many elements of uncertainty involved, it perhaps is unnecessary to 

 speculate further upon the bearing of this supply on the problem 

 under discussion. 



In the neighborhood of some of the canneries to-day, where the 

 waste from the dressed salmon is thrown into the water, there are 

 seemingly hordes of dogfish. These could be taken with the utmost 

 ease and would make an abundant source of material on which to 

 operate a fertilizer plant. It must be borne in mind, however, that 

 when the food supply which now attracts them to the canneries is 

 cut off, as it would be if a by-products plant were instituted in con- 

 nection with the cannery, they would cease to congregate there in 

 such numbers. Also, if attacked by any of the present methods of 



