Table n.— Weighted mean catches of age sockeye salmon 

 per standard tow (surface and deep tows combined), August 

 16 to September 15, by lake and year, in lakes of the Wood, 

 Kvichak, Naknek, Chignik, and Karluk systems, 1958-62 



System and lake 



Sur-_ 



face 



area 



Fish per tow 



1959 1960 1961 



Km.' 



Wood system 



Lake Aleknagik 83 



Lake Nerka 201 



Lake Beverley 90 



Lake Kulik 45 



Little Togiak Lake 6 



Kvichak system 



Iliamna Lake 2,622 



Lake Clark 267 



Naknek system (all lakes 



combined) 790 



Chignik system 



Chignik Lake 22 



Num- 

 ber 



31 5 



26 7 



3 7 



4,3 



60 



Num- 

 ber 



Num- 

 ber 



25 

 12 

 61 

 63 

 240 



183 



80 



56 



274 



153 



Num- 

 ber 



215 6 

 98 

 94 2 

 92 2 



223 7 



I 180 



Black Lake- 



Karluk system 

 Karluk Lake. 



39 



40 



Num- 

 ber 



92 2 

 31 

 2 8 

 27,0 

 39 6 



5 



6 3 



11,6 



28 9 



136,0 



35 7 



1 56 



•4 3 



I Surface tows only. 



Table \S.— Weighted mean catches of age I and older sockeye 

 salmon per standard toiv (siirface and deep tows combined), 

 August 16 to September 15, by lake and year, in lakes of the 

 Wood, Kvichak, Naknek, Chignik, and Karluk systems, 

 1958-62 



' Surface tows only. 



differences within systems between years (1961 

 and 1962 for all lakes of the Wood system) . Some 

 of these differences are examined in the follow- 

 ing analyses for individual systems. 



Wood system. — Preliminary use of the tow 

 net to sample young sockeye salmon was started 

 in lakes of the Wood system in 1957, and full- 

 scale sampling began there in 1958. The relation 



between numbers of parent spawners per unit 

 lake area and the production of age sockeye 

 salmon as measured by the geometric mean catch 

 per standard tow (mid-August to mid-Septem- 

 ber) in each of the five Wood system lakes is 

 presented for 1958-62 in figure 4. The relation 

 between catch per tow of age sockeye salmon 

 and density of parent spawners seems to differ 

 among lakes ; hence, the data must be examined 

 separately for each lake. A curve describing the 

 relation between abundance of juveniles in the 

 lake and density of parent spawners might be 

 expected to start at zero, reach a maximum, and 

 level off or decline as a result of increased mor- 

 tality due to overcrowding of adults or eggs and 

 larvae in the spawning areas or of young in the 

 rearing areas. The relatively low catch of juve- 

 niles per tow in Little Togiak Lake and Lake 



150 



01 

 LJ 

 CD 



< 

 UJ 



100 



50 







00 



50 



20 



60 



I 23456701 234567 



PARENT SPAWNERS PER SQUARE KILOMETEF 



OF LAKE SURFACE (THOUSANDS) 



Figure 4. — Relation between abundance of age sockeye 

 salmon and numbers of parent spawners per unit lake 

 area in each of the major lakes of the Wood system, 

 1958-62. The abundance of age fish is the geometric 

 mean of the abundance in tow net catches (mid- 

 August to mid-September) weighted by depth and 

 sampling area. The figure beside each point indi- 

 cates the year of sampling. 



430 



U.S. FISH AND WILDLIFE SERVICE 



