Table 25. --Length frequencies of lake trout 

 captured in Grosvenor Lake at the mouth of 

 Coville River by angling, July 29 to September 

 6, 1964. The total lengths of the live fish 

 were measured with a tape measure to the 

 closest higher inch. 



Naknek River system (Heard, Wallace, and Hartman, 

 1969), but data on length frequency and food are avail- 

 able only for fish collected with gill nets in Coville 

 Lake. Studies of the food offish in Great Slave Lake 

 (Larkin, 1948) and Great Bear Lake (Kennedy, 1949) 

 both indicated that the food of the closely related lake 

 whitefish, Coregonus clupeaformis, in these northern 

 lakes was mainly invertebrate animals and that fish 

 occurred only rarely. Larkin (1948) found fish remains 

 in only one sample (number of fish stomachs in sample 

 not given) for Great Slave Lake and Kennedy (1949) 

 reported that none of the fish in 86 samples from Great 

 Bear Lake contained food (202 fish examined). 



Briefly, the results of the examination of the 

 stomachs of 38 humpback whitefish (mideye-fork 

 length 12.1 to 55.5 cm) taken from Coville Lake 14 

 July to 12 September 1963 are as follows: 23 of the 38 

 stomachs held no food; 4 contained unidentifiable 

 mass or "white paste"; 7 contained snails or mussels; 

 and 4 contained evidence of fish ( 1 pond smelt, 1 

 whitefish, 1 sculpin, and 3 unidentifiable fish remains). 

 It appears that fish were more important in the diet of 

 humpback whitefish in Coville Lake than in the lake 

 whitefish of Great Slave and Great Bear Lakes. The 

 fork lengths of 165 humpback whitefish (Table 26) col- 

 lected with gill nets in Coville Lake from 22 June to 12 

 September 1963 ranged from 121 to 560 mm and sev- 

 eral modes were apparent. The presence of several 

 modes in the length frequency indicates several year 

 classes; a preliminary study of scale samples from 

 these fish indicated that the ages ranged from 4 to 12 

 yr. 



Arctic Char and Dolly Varden 



Arctic char and Dolly Varden cannot be differen- 



tiated without detailed examination and may have 

 been confused in many instances in the present study. 

 Therefore, I will refer to both species as char unless 

 the identification is certain. 



Char occur throughout the system in lakes and fre- 

 quently in the streams and probably eat juvenile sock- 

 eye salmon when they are available. Arctic char were 

 taken with lake trout, but in fewer numbers, in the gill 

 nets in Coville Lake and by angling in Coville and 

 Grosvenor Rivers. The stomachs of a few Arctic char 

 captured by angling in Grosvenor Lake near Coville 



Table 26. --Length frequencies of humpback 

 whitefish captured in gill nets in Coville 

 Lake, June 22 to September 12, 1963. The fork 

 lengths of fresh dead fish were measured to the 

 nearest millimeter. 



Length group (mm) 



Fish captured 



121-130 

 161-170 

 171-180 

 181-190 

 191-200 

 201-210 

 211-220 

 221-230 

 231-240 

 241-250 

 251-260 

 261-270 

 271-280 

 281-290 

 291-300 

 301-310 

 311-320 

 321-330 

 331-540 

 341-350 

 361-370 

 571-380 

 381-390 

 391-400 

 401-410 

 411-420 

 421-430 

 431-440 

 441-450 

 451-460 

 461-470 

 471-480 

 481-490 

 491-500 

 501-510 

 511-512 

 513-520 

 521-530 

 531-540 

 541-550 

 551-560 

 Total 



1 

 1 

 1 

 1 

 1 

 4 

 5 

 5 

 4 

 

 3 

 2 

 

 3 

 6 

 11 

 

 1 

 

 1 

 

 2 

 2 

 2 

 17 

 12 

 16 

 17 

 11 

 6 

 7 

 1 

 4 

 5 

 3 

 2 

 2 

 2 

 2 

 

 2 



165 



49 



