CONTENTS 



lntni(kuli(in 1 



Physical aspects and productivity of lakes 1 



Abundance ot'juvenilesockeye salmon and associated species 2 



I'redat ion as a limiting factor 4 



liationale for increasing production of smolts 5 



Spawnmg populations and sex ratios 5 



Fecundity 5 



Kgg-to-fry survival 6 



Kry-to-sniolt survival 6 



Desired try recruitment 6 



Kstitnatesof current fry recruitment 6 



Additional spawners required 7 



Adequacy ol natural spawning grounds 7 



Recommendations and conclusions 7 



North Arm 8 



Northwest Basin 8 



Firooks Lake 9 



Literature cited 9 



Figures 



1. Naknek River system. Alaska, showing the five main-stem lake basins (Coville and Grosvenor 

 Lakes, lliuk Arm, South Bay, and West End) and the three external lake basins (North Arm, North- 

 west Basin, and Brooks Lake) 2 



2. Weighted mean number of age sockeye salmon per standard tow by early (before 26 July), middle 

 (26 July-fO August), and late (after 10 August) time periods in each lake of the Naknek River 

 system. 1961-63 3 



3. Weighted mean number ot age 1 sockeye salmon per standard tow by early (before 26 July), middle 

 (26 July-lO August), and late (after 10 August) time periods in each lake of the Naknek River 

 .system, 1961-63 3 



4. Smolt production, parent escapement, and potential egg deposition in the Naknek River 

 system, 1956-69 6 



Tables 



1. Total surface area and percentage of each major basin of the Naknek River system shallower than 



.T m 2 



2. Distribution of spawning grounds of sockeye salmon and reported escapements of adult spawners 



in basins of the Naknek River system 2 



3. Mean surface water temperatures in August, mean number of age and age I sockeye salmon and of 

 pond smelt and threespine and ninespine sticklebacks, and mean fork lengths of age sockeye 

 salmon in seven lakes of the Naknek River system, 1961-63 4 



4. .Abundance of spawning grounds and average catch per unit effort of age sockeye salmon in early 



July 1961-63 in lakes ot the Naknek River system 4 



5. The system wide mean catch per tow (weighted by area of each lake) for age and age I sockeye 

 salmon in the Naknek River system in August 1961-64 and resulting numbers of smolts produced . . 4 



6. Number of adult sockeye salmon spawning in Brooks Lake and tributaries and the percentage of 

 temales. 1957-67 5 



7. Number ot adult sockeye salmon entering American Creek (Coville Lake) and the percentage of 

 temales, 1951-72 5 



8. Estimated survival of sockeye salmon from potential egg deposition to fry emigration in three 

 spawning streams in the Naknek River system 6 



9. Approximate number of try recruited annually to lake basins in the Naknek River system, assuming 



that 40' < ot the spawners were temales with an average of 4,000 eggs per female 7 



10. Additional sockeye .salmon fry that are desirable for lake basins in the Naknek River system .... 7 



11. Total existing and required number of spawners and spawning area for sockeye salmon in North 



.■\rm. Northwest Basin, and Brooks Lake 7 



