PACIFIC SALMON FISHERIES 551 



Goiter affects other animals as well as man. Horses, cattle, sheep, 

 and pigs are affected by thyroid diseases in districts where jijoiter is 

 prevalent in man. It is a serious economic problem. Before the 

 cause was well known the majority of young farm stock born in certain 

 goitrous regions died from this disease. The mortality has averaged 

 as high as 90 per cent. It has been found that a goitrous condition 

 in livestock could be prevented by feeding fish meal made from salmon 

 and herring offal, or other sea fish containing a good deal of iodine. 



A prophylactic treatment is effective in the treatment of goiter. 

 Graphic illustration to prove the point is afforded by an article in the 

 Canadian Medical Journal for May, 1924. Dr. W. D. Keith, the 

 author, says: 



Situated at the lower end of the valley at the junction of these two rivers is an 

 Indian reserve peopled by about 150 Indians whose forbears have lived in the same 

 place as far back as the knowledge of man goes. In the Indian village no sanita- 

 tion has been attempted and amongst these Indians there is no goiter nor has 

 there ever been a case recorded. Only on rare occasions has a litter of myxoe- 

 dematous pigs been born on the reserve. 



Whilst considering the lack of goiter amongst these Indians I would like to 

 draw attention to the fact that they eat a great deal of salmon. The fish come up 

 the Birkenhead to spawn, and many millions of eggs are secured at the Govern- 

 ment hatchery a mile above the village. The Indians are allowed to use the 

 spent salmon and annually cure thousands of fish for winter use. Their pigs 

 also eat the dead salmon washed ashore on the gravel banks of the stream. 

 It is quite probable that the Indians and their pigs get enough iodine from the 

 salmon to give their thyroids the necessary quantum of this element. 



It has been definitely proved that iodine exists in foods in quantity 

 large enough to be effective as a goiter prophylactic. T, H. Von 

 Fellenberg, of the Swiss Goiter Commission, has made a comprehen- 

 sive study of the distribution of iodine in food, beverages, soil, and air. 

 McClendon and Hathaway found that foods produced in goitrous 

 regions contain less iodine than those produced in nongoitrous regions 

 and come to the conclusion that "the recession of goiter that has 

 taken place in New York State during recent times is due to the greater 

 transportation facilities for sea food into the inland regions." Tressler 

 and Wells, of the United States Bureau of Fisheries, published data 

 on the iodine content of Atlantic coast fish in 1924. 



The salmon fishery of the North Pacific is the most valuable of 

 American fisheries, and its product has the widest distribution. 

 Therefore it was thought advisable to undertake a very comprehensive 

 research on the iodine content of the Pacific coast salmon. One or 

 two sets of analyses could hardly be expected to furnish accurate data 

 as to the iodine content when it is remembered that the industry is 

 carried on from northern Japan to California. 



This important research problem was undertaken by the College 

 of Fisheries in collaboration with the northwest branch. National 

 Canners Association, and was carried out by N. D. Jarvis, a member 

 of the College of Fisheries faculty. 



Samples used in this investigation were selected in such a way as to 

 include representative samples of the five species of Pacific coast 

 salmon and the steelhead trout which is closely related to the Atlantic 

 salmon from as many canning districts as possible. The different 

 species of salmon were also analyzed in a fresh condition in order to 

 determine such things as a possible loss of iodine in canning or cooking 

 by other methods. As a result it was concluded that there is no es- 



112992°— 30 10 



