﻿46 BULLETIN 2, U. S. DEPAKTMENT OP AGKICTJLTTJKE. 



is produced in large amount by the extensive fisheries on the Great 

 Lakes, but there again it is so badly scattered that its treatment to 

 any considerable extent is impracticable. These sources then scarcely 

 can be looked to for increasing the Nation's output in fish scrap. 



Among the so-called waste fish, fish commonly regarded as unfit 

 for food and applied to no other use, the dogfish are perhaps most 

 numerous in coastal waters and most easily caught. The interest of 

 the various fisheries rather demand that the number of dogfish be 

 reduced; and the experience in Canada, where through Government 

 initiative they are being converted into fertilizer, shows that they 

 are a potentially large source of fish for fish-scrap purposes, and in 

 their utilization one reasonably may expect a development of the fish- 

 scrap industry. 



This discussion has been confined to conditions as they have been 

 observed on the Atlantic coast and do not apply at all to the Pacific 

 coast. The salmon canneries on the Pacific coast produce very large 

 amounts of refuse, representing, roughly, 30 per cent of the " round " 

 weight of the salmon taken. The salmon-canning industry by no 

 means is confined to the States, but is carried on quite extensively 

 in southeastern and southwestern Alaska. A considerable amount of 

 the refuse now produced in the States is made use of in the prepara- 

 tion of fertilizers, a practice which is on the increase. In Alaska 

 practically none of the refuse is saved. A discussion of the salmon- 

 cannery waste is not in place in this report, since it is the intention 

 of this bureau to conduct an investigation during the coming summer 

 with a view to the more complete utilization of this material for 

 fertilizer purposes. Since nature has provided an abundant growth 

 of the self-perpetuating and highly potassic kelp in the neighbor- 

 hood of many of the canneries, it is hoped that the two materials 

 can be combined and a fertilizer, containing the three most desired 

 ingredients — nitrogen, phosphoric acid, and potash — be manufac- 

 tured with profit. 



OILS. 



DEVELOPMENT. 



Fish oils for many years have been among the important products 

 taken from the sea. The whale constituted the first important source 

 of the so-called fish oils and to-day yields about 3,000,000 gallons 

 annually. In addition to these, other aquatic animals, such as the 

 porpoise, the blackfish, seals, walrus, and the livers of cod, have 

 been made a fruitful source of the animal oils. 



Menhaden oil, the true fish oil, and by far the most important oil 

 produced on the Atlantic coast of the United States, first appeared 

 on the market in considerable quantity in the early sixties. The 

 large prices obtained in the early days of the industry led to a rapid 



