a few hours and 3 after 2 to 6 days. Of the latterj, 2 had been tagged 

 experimentally by members of the Pacific Oceanic Fishery Investigations„ 

 Of the 13 fish which were still livings 4 were tagged and 1 had shed 

 its tago Each of the fish which survived started feeding on the day 

 after it had been introduced. The tunny formed a compact school in the 

 ponds cruising back and forth, and occasionally darting at great speed 

 after baitfisho Except when feeding on baitfish, they tended to keep 

 to the deeper part of the pondo 



Seven of the nine yellowfin died before starting to feedj one 

 (tagged) after 12 hoursj, four after 36 hours, one after 60 hours, and 

 one (tagged) after 4 dayso All or most of these fish died during the 

 nighto Of the two which survivedj, the first was introduced on September 

 5 smd started feeding on September 12 i the second was introduced on 

 October 11 and started feeding on October 13^ Both fish were still 

 alive and in good condition on October 20 , They swam either individual- 

 ly or together;, sometimes schooling with the tunny^ In generalj, they 

 swam closer to the surface than the tunny and spent considerably more 

 time in the shallow part of the pondo 



DISCUSSION 



Although trolling is a poor method of catching tuna and other 

 pelagic fish which are intended to be kept alive^ it was the only method 

 which was practicable during the present worko As might be expected j, 

 many of the fish were fatally injured either from being dragged through 

 the water, from being hooked through vital parts of the head and throatp 

 or from being injured or suffocated during efforts to remove the hook 

 from the moutho In general , the larger fish were injured to a greater 

 extent than the smaller, Skipjack suffered a much greater mortality 

 during capture than other species because of profuse bleeding at the 

 gills whichj, accompanied by convulsive shuddering^, often occurred when 

 the fish was landed. 



It is believed that all species of tuna could be attracted 

 to the stem of the vessel with livebait and could be caught with pole^ 

 line, and barbless hook„ This method should greatly reduce the mortality 

 from catching and handling— the fish would not be towed through the water^ 

 the hook could be removed readily^, and the fish could be quickly trans- 

 ferred to the livewell from beneath the arm of the fisherman,, 



Although mortality during transportation in the livewell was 

 reduced by installing corner baffleSj, which assisted the fish in 

 following a circular course and in avoiding the wallSj, it was still 

 considerables particularly for skipjack, frigate mackerels and large 

 tunnys which still tended to bump the wallso Mortality during trans- 

 portation might be reduced by the use of a larger livewell. This is 

 indicated by results (unpublished) obtained with the Fish illCldlife SerzLce 

 vessel Hugh Mo Smith y in which 6 out of 13 skipjack (some tagged) were 

 kept alive for 24 to 36 hours in the large (5,000-gallon) baitwell,, 

 after which time it was necessary to shut down the pumps (delivering 



17 



