ECONOMICS OF THE FISHERIES 



359 



TABLE 10 



Rates of Growth of Chickens on Rations Containing 

 Various Protein Supplements 



(vitamin B12) is already (1949) being advertised to reduce the protein 

 requirement in chicken feed by as much as one-half. 



Bethke who furnished the material in Table 10 estimated that the United 

 States poultry and other animal industry could use about 375,000 tons of 

 fish meal per year (as of 1942). This amount would be the equivalent of 

 the entire production of every kind of fish in the United States and Alaska 

 in 1940. 



In 1940, the United States produced 126,736 tons of fish meal valued at 

 $5,471,557 ($43.20 per ton, average), and imported 39,233 tons valued at 

 $1,909,531 ($48.60 per ton). It produced 66,508 tons of scrap valued at 

 $2,362,264 ($35.50 per ton) and imported 6,900 tons valued at $310,586. 

 The grand total of all production of meal and scrap was 193,244 tons, worth 

 $7,833,821. 



Nearly half of this total production of meal was in very fat fish (pilchard, 

 menhaden, and herring) which because of the value of the oil can support 

 fishing operations for meal and oil only; the remainder was largely derived 

 from residues in tuna and mackerel canneries on the Pacific Coast, the 

 waste from which yielded a substantial amount of oil; from shrimp can- 

 neries and from cod, haddock, redfish, etc., filleting operations — material 

 on hand the cost of which could be charged to the canned or filleted products. 



Marine animal tissues and even seaweeds are unsurpassed as fertilizers, 

 for they furnish not only nitrogen, phosphorus, potash, calcium, sulphur, 

 etc., but also the exceedingly important trace elements, iodine, boron, 

 manganese, fluorine, copper, cobalt, and several others, some of which are 

 essential for plants, others for animals, and still others essential for both 

 plants and animals. 



