FRENCH and DUNN: LOSS FROM HIGH-SEAS GILLNETTING 



Table 11. — Total number of salmon marked and observed over varying periods of 

 lime by maturity, mesh size, material, and year, 1966-69. 



' A zero (0) indicates that the net was examined, but no marked fish were observed; a dosh 

 ( — ) indicates that the net was not examined. Numbers in parentheses indicate number of 

 possible observations for the time period; difference from the number marked is because some 

 observations were not made in rough weather. 



and carrion eaters could affect dropout rates. 

 During the haul of gill nets, and in early 

 morning hours, we often observe Steller sea 

 lion, northern fur seal, and seabirds along the 

 net string feeding on enmeshed salmon. 

 Obviously, these animals could affect the 

 results of the dro))out experiments if they 

 took marked salmon. An example of 

 suspected sea lion predation was observed 

 when, on one occasion in 1966, 25 salmon 

 were marked between hours of 2254 and 2320; 

 not a single salmon was present at the marked 



positions when the nets were hauled at 0730. 

 Sea lions were observed along the nets on this 

 occasion. On other occasions, while patrolling 

 the gill nets at night during dropout studies, we 

 have observed sea lions cruising the net and 

 taking salmon. 



Steller sea lions are probably the most 

 flagrant predators. Although examination of 

 their stomach contents has shown only 

 occasional salmon (Pike, 1958; Mathisen, 

 Baade, and Lopp, 1962; Thorsteinson and 

 Lensink, 1962; Fi.scus and Baines, 1966), there 



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