FISHERY BULLETIN OF THE FISH AND "WILDLIFE SERVICE 279 



into the Vedder River below the mouth of Sweltzer Creek which is the outlet stream 

 of Cultus Lake. 



One hundred and twenty-four thousand pink-salmon fingerlings of Tlell River 

 (east coast of Graham Island) were marked by the amputation of the adipose and left 

 ventral fins. These fish together with 750,000 unmarked individuals, from the same 

 source, were liberated in McClinton Creek, Massett Inlet. 



In 1933, lish with the following fins missing were recovered at various localities 

 in Puget Sound, British Columbia, and Chignik, Alaska: adipose 576, adipose 

 and left ventral 40, both ventrals 64, right ventral 54, adipose and right ventral 20, 

 left ventral 56. No marked fish were recovered in Sweltzer Creek, Tlell River, or 

 McClinton Creek though counting weirs were maintained in these streams. 



During 1933, Pritchard (1934b) marked 108,000 pink-salmon fry at McClinton 

 Creek, Massett Inlet, by amputating both ventral fins. The following numbers of 

 fish with fins missing were recovered at various localities in British Columbia during 

 1934: both ventrals 3,285, left ventral 195, right ventral 139, adipose 100, and left 

 pectoral 15. 10 Of these totals, 2,950 with both ventrals, 66 with left ventrals, 95 with 

 right ventrals, and 2 with adipose fins absent were recovered at McClinton Creek. 

 Thus, of the number of fish marked by removal of both ventrals 2.73 percent returned 

 to McClinton Creek. The total return was possibly higher tban 3,2S5 (3.04 percent 

 of the number marked) because all of the fish bound for McClinton Creek were not 

 sampled. 



In 1934, Kelez (1937) initiated two marking experiments on hatchery-raised 

 coho salmon at P riday Creek, a tributary of the Samish River. In the first experiment 

 26,150 fingerlings were marked by the amputation of the adipose and dorsal fins. 

 The fish were liberated during May when they averaged 47.4 mm. in length. Seven 

 marked fish were recovered as adults, or 0.027 percent of the number marked. 



In the second experiment 26,150 fingerlings of the same brood were marked by the 

 amputation of the dorsal and left ventral fins and liberated during November when 

 they averaged 101.6 mm. in length. From this experiment 469 marked fish were 

 recovered, or 1.79 percent of the number marked. 



Assuming that there was not a differential mortality caused by the marking in the 

 two groups of fish in the experiments, these data indicate a striking increase in the 

 survival rate of the fingerlings retained in the hatchery ponds for a longer period of 

 time. The returns from these experiments comprise only those fish which escaped 

 the sport and commercial fisheries. 



A series of marking experiments has been conducted on the red salmon of Cultus 

 Lake, British Columbia. In 1927 (Foerster, 1934), 91,600 seaward migrants were 

 marked by the amputation of the adipose and both ventral fins. From this marking, 

 804 fish, or 0.88 percent, were recovered during 1929 and 1930 at the counting weir 

 below Cultus Lake, these being the total number of marked fish returning to Cultus 

 Lake from this experiment. Of the 158,100 unmarked fish, 3,930, or 2.49 percent, 

 returned to Cultus Lake. 



During 1928 (Foerster, 1936a), 99,700 seaward migrants were marked by the 



'» The finding of fish with adipose fins missing, and left pectoral fins missing only confirms the long established fact that fish 

 occur in nature with fins missing. The finding of fish with right or left ventral fins missing is due in part to natural deformities, and 

 may be due to regeneration of one or the other of the fins of the fish marked both ventrals. A part of the fish with both ventral 

 fins missing may not be returns from the experiment but may be fish with natural deformities. 



