the mesh catches bsnsath its gill covers and prsYents its swimming 

 either forward or backvj-ardo Often when the fish strikes the net 

 it may penetrate the mesh until it gets caught at the thicker part 

 of the body, provided the girth is larger than the size of the 

 mesh. The fish may also be caught by becoming entangled in the 

 meshes without being gilled. 



The gill net (figo i) used in the present fishing experimentV 

 for slcipjack in Hawaiian waters was constructed on the pattern of 

 the albacore net used on tlie John N„ Cobb during its Ip^O testSo 

 Eight to 111 "shackles" of net^, each measuring 50 fathoms in length 

 and 100 meshes deep, were connected in a "string" at each settingo 

 A l6-inch air-inflatad rubber float was attached .to the float line 

 between shackles and at each end of the stringo A "sea anchor," 

 made hj lashing together three or four rope fenders around a lead 

 weight, was attached to the lead line at the free end of the first 

 shackle; wb.ile a 60- to ?0-fathom bridle was attached to the 

 float and lead lines of the last shackle o The lead line was kept 

 from rolling up on the net by a 25-pound lead ball which was 

 attached at the junction of tfco bridle and lead line^ D'uring 

 night fishing buoy lights were attached to the l6~inch rubber 

 floats at the center and both ends of the neto 



A total of l6 ohacklesj, eight of 8-ply salmon-lay nylon and 

 eight of iiO/8-ply linen^ ^era constructed in stretched-mesh sizes 

 CI U, 5j 6j ?j 9s lOj llj and 12 incheso 



The individual shackle (figo 2) was made up of tiie following 

 parts s 



(1) Kettingo The netting was made of double-lcnctted nylon and 

 linen X7hich measured 100 fathoms in length and 100 m.e3hes 

 deep with double selvage » The -Septh in fathoms ranged from 

 3-1/3 for the u-inch mesh to l6-p- for the 12~inch mesho The 

 100-fathom netting was hung on a 50-fathom float line (2 si 

 hanging ratio) ^ and was attached at every second mesh vrith 

 UO/ll-ply linsn twine. 





(2) gloat Ixn?o Tt-^e float line consisted of SO fathoms of _, 

 thread sof t-laid Manila, 17/32 inch in diameter, with an 

 additional 20 inches at each end, 



(3) Float s, Tae 6-irich diameter round glass floats were tightly 

 wrapped in l^-inch mesh webbing of No, 2? medium-laid cotton 

 thread, Tnese float? were attached to the float line with 



2 61 -thread hard-laid cotton straps 13 inches long at 2~fathom 



Tae mcdiiication and construction of the nets "-vere supervised 

 by Kalfred Yea, formerly Fishery Methods and Equipment Special- 

 ist, Pacific Oceanic Fishery Investigations, U, S, Fish and 

 Wildlifs Service, 



