Table 9. — Distribution of spawning sockeye salmon among 

 three types of spawning areas in lakes of the Wood system, 

 1955-62 



in the Igushik system. Most sockeye salmon 

 spawn on the beaches at Lake Ualik and in the 

 streams at Lake Amanka. 



Wood system. —  The distribution of adult 

 sockeye salmon among the three types of spawn- 

 ing grounds in the Wood system differs marked- 

 ly from lake to lake, but each lake has a charac- 

 teristic distribution (table 9). For example, 

 tributary creeks and the rivers between lakes 

 receive the greatest part of the spawners in 

 Lake Aleknagik (over 90 percent from 1955 to 

 1962) , whereas in Lake Beverley almost 90 per- 

 cent of the spawners use the lake beaches. The 

 spawners in Lake Nerka are usually distributed 

 about equally among the three types of spawn- 

 ing grounds. The year-to-year changes in dis- 



tribution of the spawners in the system as a 

 whole are largely the result of changes in the 

 relative escapement to each lake. 



Most sockeye salmon entering the Nushagak 

 fishing district are bound for lakes of the Wood 

 system. Tagging results in 1961 indicated that 

 spawners bound for the different lakes of the 

 Wood system may have passed through the fish- 

 ery at different times. Overlap was considerable, 

 however, and the same pattern of entry may not 

 occur every year. Time of passage to the two 

 major river spawning grounds, Agulowak and 

 Agulukpak Rivei's, was average for the system. 



Although the percentages of 2-ocean and 3- 

 ocean sockeye salmon in the run vary annually 

 with year class strength and other undetermined 

 factors, consistent differences in age composi- 

 tion tend to prevail among spawning groups. 

 For instance, in 1960-62, samples of spawning 

 sockeye salmon from Agulowak and Agulukpak 



Table 10. — Proportions of 3-ocean sockeye salmon in escape- 

 ments from areas of the Wood system, 1960-62 



Average for 

 Year and sex Agulowak Agulukpak rc'maining 



River River areas 



Percent Percent Percent 



1960 



Male 80 49 16 



Female 84 66 18 



1961 



Male -. 99 92 60 



Female 100 96 69 



1962 



Male 42 40 8 



Female 76 64 7 



Average.. 80 68 30 



Rivers consistently had a higher proportion of 

 3-ocean fish than samples from other areas of 

 the system (table 10) . 



Niiijakidi system. — The type of spawning 

 grounds used also varies greatly among the 

 lakes of the Nuyakuk system. Sockeye salmon 

 in Lake Chauekuktuli spawn almost exclusively 

 on beaches ; in Tikchik Lake they spawn only in 

 rivers and creeks. The escapement to the Nuya- 

 kuk system has a consistently higher proportion 

 of 3-ocean fish than that to the Wood system.' 



Kvichak system. — Sockeye salmon of the 

 Kvichak system spawn in streams tributary to 

 lakes, rivers between lakes, beaches of Iliamna 

 Lake, and spring-fed ponds, which are usually 

 located at the heads of small tributaries. They 



^ Burgner, R. L. 1965. Age composition of Nushagak sockeye runs 

 by river system. Univ. Wash., Fish. Res. Inst., Circ. 234, 14 pp. 



420 



U.S. FISH AND WILDLIFE SERVICE 



