FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



283 



covery of only one and six fish, respectively; hence, the percentage returns are unreli- 

 able. As the size of the migrants increases with age, the data indicate that the larger 

 migrants have the highest survival value. 



In the second experiment (table 32) 21,791 migrants were marked, 659 were 

 recovered, and a calculated total of at least 4,582 marked fish returned from this 

 experiment (at least 21.0 percent). Tbe incomplete returns from the marked 2-, 3-, 

 4-, and 5-year seaward migrants were 0.0, 20.5, 23.0 and 28.6 percent, respectively. 



The returns from the two experiments agree closely except for the 2- and 5-year 

 fish of which few were marked. If tbe data are combined as one experiment, 46,791 

 seaward migrants were marked, 1,399 were recovered, and a calculated total of at 

 least 9,733 fish returned (a minimum of 20.8 percent). 



Table 32. — Data for the second 1926 marking experiment 



1 Eased on incomplete data, see text. 



EXPERIMENTS IN 1927 AND 1928 



Fifty thousand seaward migrants were marked in both 1927 and 1928. However, 

 tbe curtailment of commercial fishing in 1929 and 1930 made it impossible to ade- 

 quately sample the runs of those years for the presence of marked fish, and the data 

 are consequently not included here. 



EXPERIMENTS IN 1929 



In 1929 (table 33), 50,061 seaward migrants were marked by the amputation of 

 the adipose and both ventral fins, 1,315 fish were recovered, and a calculated total of 

 11,157 marked fish returned from this experiment (22.3 percent). The return from 

 the 3-, 4-, and 5-year marked seaward migrants was 18.3, 24.4, and 13.5 percent, 

 respectively. As very few 5-year seaward migrants were marked and only 3 recovered, 

 the latter figure cannot be considered reliable; however, considering the returns of the 

 3- and 4-year seaward migrants, it is again apparent that the older and larger migrants 

 had the highest survival value. 



