major fishery. We recognize that to recon- 

 struct the present fishery is not necessarily 

 the best way to develop a major fishery in 

 Hawaii. New fishing techniques may be devel- 

 oped, or techniques used elsewhere for taking 

 tuna may be adapted for the Hawaiian fishery. 

 Furthermore, several methods of fishing may 

 be required to ensure optimum use of the skip- 

 jack tuna resource. 



HAWAIIAN SKIPJACK TUNA FISHERY 



The fishery for skipjack tuna (or aku, as it is 

 called in Hawaiian) has been described by June 

 (1951), who gave a short popular account, by 

 Yamashita (1958) in his analysis of the skipjack 

 tuna and bait catch statistics, and more recent- 

 ly by Uchida (1966) in his study of the catch and 

 effort statistics collected in the Hawaiian skip- 

 jack tuna fishery. This pole-and-line, live-bait 

 fishery is conducted from 17 sampan-type ves- 

 sels which range between 17.8 and 23.3 m. in 

 registered length. A supply of live bait, usually 

 the anchovy or nehu, Stolephorus purpureus , 

 must be caught and loaded into the baitwells 

 before the vessel departs for the offshore fish- 

 ing grounds. Some bait is captured at night, but 

 most of it is taken during the day. The delicate 

 nehu does not survive long in the baitwells, so 

 a fishing trip is usually limited to a day or at 

 most a few days. Lacking mechanical refrig- 

 eration systems, the fishing vessels usually 

 carry ice to preserve the day's catch. 



The fishery is highly seasonal. As estimated 

 by weight of landings, the availability of fish is 

 highest in the period from June through August, 

 lowest in November through March, and inter- 

 mediate in the remaining months. On the aver- 

 age, monthly catches in June-August are more 

 than six times those in November-March. 



The fishing sequence for a boat begins with a 

 period of baiting.-' Fishermen usually catch 

 baitfishes during the day by surrounding a 

 school with a seine; the fish are then trans- 

 ferred to the baitwells. Fishermen are careful 

 to avoid injuring the baitfishes, for mortalities 

 may be heavy. If the amount of bait caught dur- 

 ing the day is not sufficient for the trip to sea, 

 the vessel may wait until dark and then attempt 

 to fish for bait at night. At night, baitfishes 



— "Bait" and "baiting" are colloquial terms 

 (used here for convenience) by which tuna fisher- 

 men refer to the catching of bait. 



which are attracted to a submerged light are 

 seined and transferred to the vessel. Several 

 days or nights of work may be required to 

 catch enough baitfish to justify the start of 

 fishing. 



The Hawaiian skipjack tuna fishermen depend 

 on birds to locate fish. On a fishing trip, the 

 fishermen search for bird flocks, which are 

 usually associated with schools of fish. Several 

 skipjack tuna schools commonly are encoun- 

 tered and fished during a fishing trip. Other 

 species of fish are sometimes taken, princi- 

 pally small yellowfin tuna or ahi, Thunnus 

 albacares ; dolphin or mahimahi, Coryphaena 

 hippurus ; and little tuna or kawakawa. Euthynnus 

 affinis . 



Fishermen abandon a tuna school when the 

 fish stop biting. Immediately after fishing, the 

 catch from each school of tuna is placed in the 

 baitwells that have been emptied of the bait in 

 the course of fishing. Scouting ends when (1) 

 the supply of baitfishes is exhausted by fishing 

 or death in the baitwells, (2) the catch of skip- 

 jack tuna must be taken to port before it spoils 

 or when the vessel is loaded, or (3) darkness 

 approaches. 



On arrival back in port and unloading of the 

 catch, the vessel may or may not attempt night 

 baiting, depending on whether a sufficient sup- 

 ply of bait remains in the wells or on the phase 

 of the moon. (Night baiting is rarely attempted 

 on bright, moonlight nights because the nehu 

 fail to congregate around the submerged light.) 

 The vessel departs for the tuna or baiting 

 grounds early the next morning. 



A period of baiting followed by a period of 

 fishing may last from 1 to 7 days. Several days 

 may be required to accumulate a load of bait, 

 and in turn several days' fishing may follow. 

 These episodes may be separated by a day or 

 two of rest. This sequence appears to be 

 characteristic of the fishery. In addition to 

 fishing for bait and tuna, fishermen spend time 

 unloading the catch, loading ice, repairing and 

 maintaining the vessel, and traveling in the 

 vessel from port to the bait and fishing grounds. 



DISTRIBUTION OF TIME SPENT 

 IN SKIPJACK TUNA FISHING 



To study the efficiency of operation among 

 the vessels of the Hawaiian skipjack tuna fleet, 

 we examined the detailed logbooks that captains 

 of two vessels had kept in 1952 and 1953. If 



