UTILIZATION OF THE FISH WASTE OF THE PACIFIC OCEAN. 69 



Present practice makes the greater part of this available for the 

 manufacture of fertilizer. Since the material is cooked before dis- 

 carding, some of the oil has been released, thus detracting from the 

 value of the material as a source of oil. What proportion of oil 

 thus is lost can not be said. It is probable that only a little more 

 cooking is necessary to render the material suitable for pressing. 



At present a considerable part of the cooked meats (about 500 tons 

 per year) is disposed of for the manufacture of fertilizer. To effect 

 this the waste is only dried in a steam drier, no attempt being made 

 to recover the oil present. During the season of 1913 about 50 tons 

 of tuna fertilizer were prepared. A sample of this was analyzed 

 by J. E. Lindemuth, the results of which are given in Table XVI. 



The tuna-canning industry shows promise of development. The 

 fine qualities of the product have brought it into demand. The 

 present pack represents an initial or round weight of 16,400,000 

 pounds. If all the waste from this (70 per cent) were saved, it 

 would yield about 5,700 tons, or if only that produced at the can- 

 neries were saved it would amount to about 4,000 tons of undried scrap. 



HALIBUT. 



Halibut are caught by hook and line, trawl, or " ground line." At 

 the end of each day's fishing the catch is partially dressed, the 

 viscera being removed, and is packed in ice for transportation to 

 the halibut stations for the final preparation for market. The waste 

 produced in the preliminary dressing is thrown overboard. At the 

 halibut stations, generally fish-freezing stations, the heads are 

 severed and the fish are subjected to a final cleansing before being 

 frozen for storage or shipment. The heads represent about 14 per 

 cent of the weight of the fish as delivered at the stations. The pres- 

 ent practice is to throw these into the water at the stations, at the 

 end of the day's work, in the manner most convenient. As the 

 greater portion of the halibut caught are marketed fresh or frozen, 

 they are shipped whole without further cutting, with the result that 

 the only waste from them produced at the stations is the heads. 



During the past season (1913) the Alaska halibut fisheries pro- 

 duced 13,437,800 pounds of halibut. This is the weight of the pre- 

 pared fish. In producing this weight, about 1,100 tons of heads 

 were discarded, and probably an equal weight of viscera. To pre- 

 serve the latter and make it available for rendering the oil and 

 preparing the residue for fertilizer, the fishing boats would have to 

 be equipped with ice-cooled tanks for receiving the viscera. This 

 would be objected to on the part of the operators, as frequently all 

 available space on the fishing steamers is taxed to its utmost to 

 accommodate the fish of far greater value than the viscera. It is 



