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SINGLE HOOKED 



DOUBLE HOOKED 



Figure 3. — Six methods of baiting. 



Sardine 



Two experiments comparing single hooking with two variations of double 

 hooking were carried out on John R. Manning cruise 12. The first experiment was 

 conducted on station 1 by alternating, by baskets, single-hooked sardines (fig. 3a) 

 with double-hooked sardines (fig. 3e) for the entire set of 40 baskets. Of 120 

 baits recovered, 57 were single-hooked and 63 double. The lack of difference in 

 bait returns is reflected in the catches, which consisted of 12 and 9 fish respec- 

 tively. The experiment on station 6 was similar to that carried out on station 1 

 except that the double-hooked baits were fastened to the leader with rubber bands 

 (fig. 3f ) . Because of the difficulty of baiting in this fashion, there were 3 

 times as many baskets (30 to 10) with single-hooked baits. Based on this ratio, 

 there was a significantly higher number of double-hooked bait returns, as shown 

 in table 5. The data on the catch (table 5) were insufficient for an analysis, 

 but indicate no difference in catch with method of baiting. 



A more extensive experiment conducted on Manning cruise 18 (December 

 1953) used sardines as bait and employed the single and double hooking methods 

 illustrated in figures 3a and 3d. The results, given in table 6, show a definite 

 advamtage for double hooking In terms of bait return. Despite the higher bait 

 returns from double hooking, it appears from the data in table 6 that the catch 

 was not affected. This is an indication that a large part of the single-hooked 

 sardine loss occurs during hauling, for if the loss occurred during the soaking 

 period, it should be reflected in the catch. More direct evidence that baits are 

 actually lost during hauling is furnished by observations made by the author on 

 several of the longllne cruises discussed In this report. From a total of approx- 

 imately 1,500 baskets observed during the hauling operation, 55 sardine baits were 



