FISHERY BULLETIN: VOL. 71, NO. 3 



similar in a large gill net fishing fleet, sub- 

 stantial numbers of salmon would be lost over a 

 fishing season. 



Based on the data reported herein, it was 

 concluded that a substantial loss of salmon 

 could occur in the Japanese high-seas fishery. 

 Applying an estimated loss of from 20% (for 

 maturing salmon) to 33% (for maturing and 

 immature salmon combined) to the average 

 annual catch of 22 million salmon by the 

 mothership fishery, the estimated annual loss 

 from gill nets would range from 5.5 to 10.8 mil- 

 lion fish. Of this loss, it was estimated that an 

 average of 0.6 to 1.8 million sockeye salmon of 

 Bristol Bay origin would be lost annually by 

 the Japanese mothership fishery. 



In addition to losses due to dropouts, there 

 is an attendent loss due to fallouts. If 1% of the 

 total landings of the Japanese mothership fleet 

 were lost, this would average over 200,000 fish 

 each year, of which 25,000 sockeye salmon of 

 Bristol Bay origin would be lost on the 

 average. 



Although the ultimate fate of salmon drop- 

 ping out of gill nets is not known, evidence 

 from the literature suggests that the mortality 

 of salmon escaping from gill nets is high. The 

 potential loss of salmon (due to dropout and 

 predation) and waste of the resource, there- 

 fore, amount to substantial numbers of salmon. 



ACKNOWLEDGMENTS 



We thank all of the following who helped 

 patrol the gill nets at night in the North Pacific 

 Ocean in small boats during wind, rain, and 

 fog: R. Bakkala, N. Budnick, R. Carlson, D. 

 Craddock, T. Dunatov, W. Gronlund, F. Lund, 

 W. Peterson, D. Sutherland, and R. Thompson 

 of the Northwest Fisheries Center, National 

 Marine Fisheries Service (NMFS), NOAA, 

 Seattle, Wash.; M. Berg, J. Svendsen, and E. 

 Tveit from the NMFS charter vessel Pcuxigou; 

 and R. Ware from NMFS charter vessel St. 

 Michael. 



R. Fredin, D. Worlund, and G. Hirschhorn, 

 Division of Fisheries Data and Management 

 Systems, Northwest Fisheries Center, NMFS, 

 NOAA, Seattle, provided the experimental 

 design used in 1965. 



LITERATURE CITED 



Craddock, D. R. 



1969. Comparison between gill net and purse seine 

 catches of salmon in the North Pacific Ocean. 

 Masters Thesis, Univ. Washington, Seattle, 97 p. 

 Doi,T. 



1962. Approach from population dynamics to ratio 

 of salmon dropping off gill nets. [In Jap.] Bull. 

 Tokai Reg. Fish. Res. Lab. 34:13-18. (Transl. Natl. 

 Mar. Fish. Serv.. Northwest Fish. Cent., Seattle, 

 Wash.) 

 Fiscus, C. H., AND G. A. Baines. 



1966. Food and feeding behavior of Steller and 

 California sea lions. J. Mammal. 47: 195-200. 

 Fisheries Agency of Japan. 



1959. Report of research on salmon conducted by 

 Japan in 1958 for the International North Pacific 

 Fisheries Commission. Int. North Pac. Fish. 

 Comm., Annu. Rep. 1958, p. 50-73. 

 French, R. R. 



1966. Salmon distribution and abundance studies. 

 Int. North Pac. Fish. Comm., Annu. Rep. 1964, 

 p.91-101. 



French, R., R. Bakkala, J. Dunn, and D. Sutherland. 



1971. Ocean distribution, abundance, and migra- 

 tion of salmon. Int. North Pac. Fish. Comm, Annu. 

 Rep. 1969. p. 89-102. 



French, R., R. Bakkala, J. Dunn, D. Sutherland, and 

 P. Washington. 



1972. Ocean distribution, abundance, and migration 

 of salmon. Int. North Pac. Fish. Comm., Annu. 

 Rep. 1970, p. 76-90. 



French, R. R., D. R. Craddock, R. G. Bakkala, and 

 J. R. Dunn. 



1969. Ocean distribution, abundance, and migration 

 of salmon. Int. North Pac. Fish. Comm., Annu. 

 Rep. 1967. p. 85-96. 



French, R., D. Craddock, R. Bakkala, J. Dunn, and 

 D. Sutherland. 



1970. Ocean distribution, abundance, and migration 

 of salmon. Int. North Pac. Fish. Comm., Annu. 

 Rep. 1968, p. 79-90. 



French, R., D. Craddock, R. Bakkala, J. Dunn, and 

 K. Thorson. 



1967. Ocean distribution, abundance, and migra- 

 tions of salmon. Int. North Pac. Fish. Comm., 

 Annu. Rep. 1966, p. 78-89. 



French, R. R., D. R. Craddock, and J. R. Dunn. 



1967. Distribution and abundance of salmon. Int. 



North Pac. Fish. Comm., Annu. Rep. 1965, p. 



82-94. 

 Fukuhara, F. M. 



1971. An analysis of the biological and catch 

 statistics of the Japanese mothership salmon fishery. 

 Ph.D. Thesis, Univ. Washington, Seattle, 370 p. 



Hanson, H. A., P. D. Zimmer, and I. J. Donaldson. 



1950. Injured and dead fish in the vicinity of Bonne- 

 ville Dam. U.S. Fish Wildl. Serv., Spec. Sci. Rep. 

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