male at American Creek (Coville Lake) and 3,553 

 eggs/t'emale at Miss 42 Creek (Northwest Basin) in 1972. 



Kgg-to-Fry Survival 



Ten estimates of survival from potential egg deposition 

 to fry emigration have been made in three streams in the 

 Naknek system (Table 8). The number of fry entering 

 nursery lakes averaged nearly 9'f of potential egg deposi- 

 tion. 



Table 8. — Estimated survival of soi'ke>e salmon from potential cuk 

 deposition to fry pmigralion in three spaunin^ streams in the 

 .N'aknek River svstem.' 



Number of Percentage survival 



'Michael L. Dahlberg, Fisheries Research Biologist, Northwest & 

 Alaska Fisheries Center Auke Bay Fisheries Laboratory, National Marine 

 Fisheries Service, NOAA, P.O. Box 1.15, Auke Bay. AK 99821. Pers. 

 commun. Mav 1976. 



Fry-to-Smolt Survival 



Assuming that the annual escapement was 994,000, 

 40% of the fish were females, and the average female car- 

 ried 4,000 eggs into the system, the annual potential egg 

 deposition averaged 1,590 million. The average number 

 of sockeye salmon smolts emigrating from the Naknek 

 River from 1956 to 1969, from which the average annual 

 escapement was figured, was 12.2 million. From these as- 

 sumptions we can calculate the average annual fresh- 

 water survival (S> from potential egg deposition to out- 

 migrating smolts as follows: 



12.2 (smolts) 

 1,, 590 (eggs I 



0.008. 



Average fry-to-smolt survival can be approximated from 

 the tollowing relationship: 



S = S, X $,, 



where S' is the estimated total freshwater survival from 

 potential egg deposition to smelt, Si is the estimated egg- 

 to-fry survival, and ,S'j is the estimated fry-to-smolt sur- 

 vival. 



Using the values 6' = 0.008, and .S, = 0.09, we calcu- 

 late S, to be 



s. = ^ 



0.008 ^ 

 0.09 



0.09. 



Desirable Fry Recruitment 



There is no consensus on the level of sockeye salmon 

 fry recruitment to a lake that produces the maximum 

 outmigration of smolts. It is generally recognized that op- 

 timum fry recruitment will vary among lakes, depend- 

 ing on various biotic factors such as primary and sec- 

 ondary productivity and abiotic factors such as length of 

 growing season. Data on primary productivity presented 

 by Burgner et al. (lo69z for 10 western Alaska sockeye 

 salmon lake systems reveal that the Naknek system has 

 intermediate rankings with regard to carbon fixation and 

 standing crop of phytoplankton. However, the Naknek 

 system ranks relatively low with regard to escapement of 

 spawners per 100 ha of lake area. Information is not 

 available to compare all basins within the Naknek 

 system in regard to production of food for juvenile 

 salmon and distribution of spawners. 



The number of spawners, potential egg deposition, and 

 resultant smolt production for the Naknek system for the 

 14 brood years 1956-69 are shown in Figure 4. The higher 

 levels of smolt production appear to result from escape- 

 ments of slightly more than 1 million adult sockeye 

 salmon, but for our estimates we used 1 million. Ellis 

 (1974) concluded that juveniles resulting from escape- 

 ments of up to 1 million adults did not overburden the 

 food supply. 



Thus, fry-to-smolt survival is estimated to average about 

 9%. 



" 0.5 1.0 1.5 2.0 



FISH IN PARENT ESCAPEMENT (MILLIONS) 



Figure 1. — Smoll production, parent escapenu'iit. and potential egg 

 deposition in (he Naknek system, l!».'t*i-(>M. Dashed line represents !).'>' '■ 

 confidence hounds of the expected smoll production. .Modified from 

 figure '.\7\ of Pella and -laenicke (see text footnote (»). 



Estimates of Current Fry Recruitment 



Our estimates of current levels of fry recruitment to 

 the various lake basins are based on estimates of spawner 

 escapement, sex ratio, fecundity, and egg-to-fry survival. 



