FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



287 



EXPERIMENTS IN 1932 



Four marking experiments were conducted (tables 39-42). The fish marked in 

 the first experiment were captured on May 27 and 28; those in the second experiment 

 on May 30, 31, June 3, and 4; the fish for the third experiment on June 6, 7, 8, and 

 9; and the fish in the fourth experiment on June 11, 12, and 22. The experiments 

 were planned, in part, to determine whether or not a differential mortality in the 

 ocean existed betweeD fish marked b/- the amputation of the adipose and one ventral 

 fin and fish marked by the amputation of the adipose and one pectoral fin, and to 

 determine if a correlation existed between the time of occurrence of fish in the migra- 

 tion period and the time of their occurrence in the runs on their return as adults. 



In the first experiment (table 39), 15,000 seaward migrants were marked by 

 amputation of the adipose and right ventral fins, 341 fish were recovered, and a cal- 

 culated total of 2,957 marked fish returned (19.7 percent). The return from the 3-, 

 4-, and 5-year marked seaward migrants was 19.1, 20.5, and 3.0 percent, respectively. 



Table 39. — Data for the first 1932 marking experiment 



