cat; e expekdjen £ar 



lysis of earlier longline cruises indicated that the catch 

 of yellowfin and bigeye tuna was g] r on the deeper-fishing ho 



(Murphy 2nd Shomura 1953). If abundance "unction of depth, 



it should be oossible to increase the catches by fis) at deeper levels. 



Accordingly 5 baskets of special gear w .shed at each of 16 stations 



on L^an-'.i.ig Cruise 11. On stations 10-17 (1G0° longitude) the gear had 

 ^O-fathort float lines ii il 10. -fathom float lines 



were I Ions 19-26 (l£ de). Operationally, the 



special gear wor 1 



The haulir. was a little greater because 



of the long float lines, and the rain on the line 



hauler, but there did not appear to be any reason why such gear could 

 not be used in large-scale or 



The catches of the 19 3f egular gear that were hauled 



after the break and 1] lsed as 



a basis for comparison - *der iy pi b] f fact of unequal 



arisons, 18, indicate there was 



little if any difference in the -catching efficiency of the two 



types of gear. It is of interest ths ore, the species showing 



the greatest relative catch on the deep hooks of the standard baskets, 

 shows -_ 60-perc ni 3 in catch ever the expected when f?0-fath< 



Float lines were used, even th 3 is not statistically 



significant,. In regard to relat - 1 depth distribution, the special 

 sr yellowfin on the ooks and equal numbers of 



albacore at all t! •■ ■■■ 'oak levels in 1st to the usual distribution 



on the st ' of 6 the 



askets of trasted wii no albacore 



on the shallow hooks of 320 bask ! ;ear, ap - int. 



The ■ ] " J a are too scant to car'- indica- 



tion ; float lines were allow ooks to sink 



deep ' t the deepest hoc. [the greate .'• con- 



centration of yellowfin and all of the hoc - best 



albacor' I hs„ 



Table 18. — Analysis of catch of tuna with type of gear used. 



±1 The special gear on stations 10 through 17 differed from 



the regular gear by having ^0- fa thorn float lines. On 



stations 19 through 26 the length of float lines of the 

 special gear was 30 fathoms „ 



27 



