During 1951s attempts were made to catoh various species of 

 tuna, transport them in a ship's livewell, and establish them in ponds 

 and tanks at the Coconut Island branch of the Hawaii Marine Laboratory. 

 The objective was to provide specimens for a study of the reaction of 

 tuna to various types of stimulio 



The work was undertaken under contract (NooI6fw-1333l) between 

 the University of Hawaii and the Department of the Interior, Fish eind 

 Wildlife Service, Pacific Oceanic Fishery Investigations <> 



FISHING 



Fish were caught by surface trolling from the University's 

 46-foot vessel, the Salpa (fige l)<, Fishing took place exclusively in 

 an area centered off Mokumanu (Bird) Island, near Kaneohe Bay (fig» 2)o 

 S/bst of the fish were caught within 2 miles of the island. 



In trolling, six lines were used, two (90 feet long) from each 

 of two outrigger poles, and one (30 feet long) from each side of the 

 stern. A variety of relatively small lures were used as follows: usually 

 greenish or brownish, pliable-rubber imitation squid on the outside out- 

 rigger lines; gray or red, metal -headed imitation squid ^.vith white rubber 

 arms on the inside outrigger lines; and red or white, motal-headed, 

 feathered jigs on the stem lines. For the most part, small (No. 3 or 

 5, Japanese) double, barbed hooks were used with the lures. Both lures 

 and hooks were small because small fish, not over about 8 pounds in 

 weight, were desired. It has been our experience that large fish will 

 take both large and small lures, but that small fish will usually take 

 only small lures. Moreover, the small hooks caused less damage to the 

 mouth parts and head of the fish than large hooks. Single barbed and 

 barbless hooks were tried but discarded as almost invariably the hooked 

 fish escaped before it could be landed. 



Sixty fishing trips were made from January 18 to October 18, 

 1951, each trip lasting for about 2-j hours, usually from 7«30 a.m. to 

 10 a.m. Fishing time was recorded as the interval between leaving and 

 returning to No, 1 buoy (fig, 2)„ In trolling, all members of the crew 

 (usually three in number) scanned the waters for active flocks of terns 

 and boobies, which might be feeding above tuna schools. When an active 

 flock was located, the Salpa headed towards it and trolled around the 

 fringe of the flock, occasionally cutting through it. Usually fish were 

 caught on one or several of the lines during this maneuver. Occasionally 

 tuna and dolphin were caught when no active bird flocks were seen. 

 Occasionally also, the dolphin catch was increased by towing one hooked 

 fish astern at slow speed. This attracted the school to the stem and 

 enabled more fish to be caught either with the trolling lines manipulated 

 by hand so that the lures were in the school, or with regular tuna poles 

 (June 1951) which were used only on such occasions. The speed of the 

 Salpa in normal trolling operations was from 6 to 7 knots. 



