fishing explorations, and their abundance and 

 availability are apparently sufficient to support 

 limited trawling on Lake Superior. Chubs 

 appear to average larger in Lake Superior than 

 on the other Great Lakes, and about 10 percent 

 of the trawl-caught chubs were of acceptable 

 size for human food as a smoked or fresh 

 product. The catch records of chubs by cruise 

 is summarized in table 3, andthebest 1/2 -hour 

 chub catches during each cruise are sum- 

 marized in table 4. Of the 174 exploratory 

 drags catching chubs, 59 were of commercial 

 significance (a catch rate of 250 pounds or 

 more per one -half hour of trawling). The 

 average catch for effective effort was 240 

 pounds. 



Commercially significant catches of chubs 

 were taken in all but one district and at more 

 than one location on every cruise. Commer- 

 cially significant concentrations of chubs were 

 found all along the south shore but in specific 

 geographic locations (fig. 7). Few significant 

 chub catches have been made in waters shal- 

 lower than 35 fathoms, and none deeper than 

 55 fathoms. Three -quaters of all the significant 

 catches were made in the 35- to 45 -fathom 

 range. 



Almost half of the total fishing effort was 

 expended in District IV where consistently 



Table 3. — Summary of catch records of chubs in 

 Lake Superior by cruise, 1963-65 



Cruise 

 No. 



Total 

 drags 



Signifi- 

 cant 

 catches 



Total 

 catch 



Catch 

 rate per 

 l/2-hour 



effort 



Average 

 1/2-hour 

 catch for 

 effective 

 effort 



Table 4. --Summary of largest chub catch for each cruise 



North of Whltefish Point 

 Off Grand Traverse Bay 

 Keweenaw Bay 



North of Whltefish Point 

 Off Bete Grise Bay 

 Off Shelter Bay 



305 



380 

 1,210 



770 

 1,650 



950 



good chub catches were found. An analysis 

 of the depth distribution of chubs during each 

 of the five cruises in this district is shown 

 in figure 8. Only small amounts were caught 

 shallower than 30 fathoms during cruises 18, 

 20, and 29, and none was taken shallower than 

 this depth during cruises 23 and 25. The best 

 catch rates throughout the area were obtained 

 at the 45 -fathom depth during all but the last 

 cruise when the highest catch rate was at the 

 40-fathom interval. The best individual catches 

 were also made at the 45 -fathom interval on 

 cruises 23 and 25; however, on cruises 18, 

 20, and 29, the best individual catches were 

 made at the 40-fathom interval. 



A study of commercial production potential 

 was made between Grand Traverse Bay and 

 Bete Grise Bay on cruise 25 (fig. 9). Twelve 

 drags to test production potential, totaling 

 8-2/3 hours of fishing effort, caught 12,230 

 pounds of chubs, 40 pounds of smelt, 129 

 pounds of lake trout, 96 pounds of lake herring, 

 and 25 pounds of miscellaneous species. These 

 drags averaged 1,475 pounds of fish per hour 

 of which 1,410 pounds were chubs. Ninety- 

 four percent of the chubs measured in these 

 catches were over 9 inches long and averaged 

 3.8 fish in the round to the pound. Nearly 

 all the lake trout caught in this study were 

 returned to the water alive and successfully 

 re-entered subsurface levels. 



During the production trials, six drags with 

 a 72-foot headrope, two-seam wing trawl 

 were compared with six drags made with the 

 5 2 -foot standard assessment trawl. The highest 

 individual catch rate was obtained eventually 

 with the bigger trawl (2,200 pounds in 40 

 minutes), but the 52-foot trawl outfished the 

 larger one by an average hourly rate of 1,575 

 pounds to 1,270 pounds. I believe that increased 

 experience with the larger net would lead to 

 an improvernnent in its effectiveness. 



Smelt 



In total poundage caught, smelt was the 

 second most abundant species taken during 

 the fishing explorations. Smelt were in over 

 half of all drags and composed 10 percent of 

 the total catch, but only 18 drags netted over 

 100 pounds per l/2-hour drag, and the average 

 catch for effective effort for all cruises was 

 only 32 pounds. The overall catch rate was 

 only 17 pounds per 1/2 -hour effort. Smelt 

 were found most consistently in Huron and 

 Keweenaw Bays and off Duluth. 



Commercially significant catches of smelt 

 were taken on four cruises; however, very 

 poor catches were made on cruises 14 and 25. 

 During cruise 14 in Whltefish Bay, not more 

 than 15 pounds per drag were taken. On Cruise 

 18 in the central portion of the lake, good 

 catches of 300 and 320 pounds were taken in 

 Huron Bay at 25 and 30 fathoms, whereas in 

 Keweenaw and Grand Traverse Bays, the smelt 



12 



