FISHERIES OF ALASKA IN 1907. 29 



from natural causes. Mr. C'haiuberlain" found but one case among 

 many thousantls of redfish examined prior to 1906. During the sum- 

 mer of 1007 an examination of 2,672 redfish from southeast Alaska, 

 most of them taken south of Ketchikan, revealed none lacking either 

 ventral fin. Of 5,950 humpback salmon iTom the same general region, 

 one left ventral was entirely lacking, but in no case was the pair 

 absent. The ventral fins are, moreover, seldom mutilated. The 

 most frequent abnormality is asymmetry of size in the pair, one fin 

 being dwarfed, but otherwise usually perfect. This examination will 

 be continued until data are obtained upon a large number of salmon. 



Considering only the marked salmon coming back to the Naha, the 

 return is nearly 1 per cent on fry liberated at the age of about o 

 months. Most of these returned in 1907, and indicate 4^ years as the 

 approximate age of the redfish from the time of hatching to sexual 

 maturity. That all individuals of a given hatching do not mature in 

 the same year is not improbable, and is indicated by the return of the 

 Naha marked fish at Yes Lake in 1906. The same evidence also indi- 

 cates that ^\ hile a part of a given hatch of salmon may return to the 

 parent stream a greater part may go to other streams of the region. 



Kxjteriments at Klawak. — Mr. H. F. Swift, superintendent of the 

 Klawak cannery, reports three experiments in marking salmon at the 

 Klawak hatchery. A period of one or two years intervened between 

 the markings. The mark consisted in the removal of the adipose fin 

 from redfish fingerlings taken from Klawak Lake, at a presumed age 

 of about 1^ years. In the first experiment about 1,000 fish were 

 marked, in the other two about 2,000 each. A return of about 20 per 

 cent is claimed in each of the first two cases, and about 5 per cent in 

 the third, the return in every case occurring the third year after 

 the marking. The fingerlings marked must have been in part, pre- 

 sumably much the smaller part, the product of natural spawning. 



HATCHERY REBATES. 



The August grand jury of the third judicial district, sitting at 

 Valdez, in its final report strongly urged that the provision of the 

 Alaska fisheries law exempting owners of private salmon hatcheries 

 "from all license fees and taxation of every nature at the rate of 10 

 cases of canned salmon to every 1,000 red or king salmon fry lib- 

 erated," be repealed and that the canneries be compelled to pa}^ the 

 regular license tax of 4 cents per case of canned salmon, without 

 rebate, as heretofore. While there is no doubt that the fund for 

 the building of roads, etc., in Alaska has suffered somewhat from the 

 exemptions granted by the new law, another side of the question 

 deserves consideration. At the present time there are four hatcheries 



"See " Some Ob.seivalioiis on Salmon and Tront in Alaska." P. M. Chamberlain, 

 Bureau of Fisheries, Document No. 627, p. 66-68. 



