strikes the lure, the fisherman pulls on the tag line, re- 

 trieves the pole, and flips the hooked fish aboard. A mix- 

 ture of dead, salted "shirasu" (larval fish) and boiled 

 noodles (somen) is chummed over the side while the 

 boat circles the school counterclockwise, thus keeping 

 the boat close to the dead shirasu and boiled noodles 

 which are pushed toward the school by the rotation of 

 the propeller. When biting is fast, the poles are no longer 

 "trolled"; rather, each fisherman grasps one pole and 

 flips the hooked fish aboard. 



The use of other commercial gear depends on avail- 

 ability of Auxis and the efficiency of the gear. Among 

 them are trolling line, handline, small-scale longline, 

 and a wide assortment of nets including traps (set net, 

 pound net), gill or drift nets, bag net, ring net, beach 

 seine, otter trawl, and purse seine. In some countries 

 where these gears are in use, Auxis are not the principal 

 species sought by the fishermen; rather, they are caught 

 when other species of tuna such as yellowfin, bluefin, 

 and skipjack tunas either become unavailable or are 

 relatively low in abundance. Some of these gears are 

 discussed in the section that follows. 



In the Philippines, purse seines appear to be effective 

 in taking Auxis. To accelerate commercial develop- 

 ment of pelagic fisheries, chartered commercial purse 

 seiners, and research and survey boats under the South 

 China Sea Fisheries Development and Coordinating 

 Programme have been doing exploratory fishing includ- 

 ing the detection and estimation of the abundance of the 

 pelagic resources. Rosenberg and Simpson, reporting on 

 voyage 3 of the purse seiners Royal Venture and South- 

 ward Ho, stated that during the period when both 

 worked the southeasterly portion of Moro Gulf, some of 

 the floating logs seen had good signs of tuna. About 26,0- 

 00 kg of "Tulingan" (probably Auxis) and kawakawa 

 were landed, composing roughly 21'~r of the landings of 

 the two seiners. Rosenberg and Simpson noted that 

 large quantities of kawakawa and Auxis are consumed 

 fresh in the Philippines, but there is no market for them 

 when frozen. 



The total landings of tuna by the two seiners after 

 voyage 4 reached 31,000 kg of which Auxis represented 

 about ll'f. Southward Ho usually caught less Auxis 

 than the Royal Venture because the former used a 

 slightly larger mesh in the bunt section of the seine 

 (Rosenberg et al.'). The result was that Auxts, which are 

 smaller than either skipjack or yellowfin tunas, tended 

 to gill and had to be discarded. 



In Indian waters, A. rochei occasionally occur in very 

 large schools close to shore and large quantities are 

 usually taken by beach seines (Jones and Silas 1964). 



'Rosenberg. K. J., and A. C. Simpson. 197.5. Pelagic fisheries devel- 

 opment—Trip reports, chartered purse seine vessels. (Trip reports of 

 chartered purse seine vessels Royal Venture and Southward Ho, covering 

 Voyage .3. 9 February' to 26 March 1975. ( South China Sea Fish. Dev. 

 Coord. Programme. Manila. .June 197.5. SCS/7,5AVP/10, 28 p. 



'Rosenberg, K. •!.. A. C. Simpson, and C. M. Rcnwick. 197,5. Pelagic 

 fisheries development — Trip reports, chartered purse seine ves- 

 sels. (Trip reports of chartered purse seine vessels Royal Venture and 

 Southward Ho, covering V'oyage 4. 9 April to 24 May 197,5.) South China 

 Dev. Coord. Programme. .Manila. -June 1975. SCS^5AVP12, 36 p. 



Silas (1967b) rejaorted that Auxis are very rare in the 

 multiple troll catches made along the Tinnevelly coast 

 in the Gulf of Mannar but are caught in small numbers 

 together with skipjack tuna on pole-and-line and troll 

 gear in the Laccadive Islands. 



India, like the Philippines, has also been active in up- 

 grading her tuna fishing capability. In January 1962, the 

 Indo-Norwegian Project made the RV Varuna available 

 to the Central Marine Fisheries Research Institute of In- 

 dia for exploratory fishing and oceanographic surveys in 

 the Indian Ocean (Silas 1969). Two types of gear — drift 

 net and purse seine — were used. Each unit of nylon drift 

 net was 25.85 m long and 6.10 m wide. Five mesh sizes 

 were used— 2.5, 5.5, 10.0, 12.5, and 17.0 cm. The smaller 

 mesh sizes captured juvenile pelagic fishes whereas the 

 larger meshes captured A. t hazard tmd A. rochei in both 

 the continental shelf and oceanic areas. Figure 42 shows 

 the number of drift net sets, the number of specimens 

 collected, the average weight, and the length-frequency 

 distribution of Auxis in the tuna catch. 



Initial attempts at exploratory purse seining in the 

 Laccadive Sea by the RV Varuna were unsuccessful, but 

 subsequent attempts by the MV Tuna were reasonably 

 successful (Silas 1969). The purse seine used in the ex- 

 ploratory work was 540 m long and 67 m wide with a 

 mesh size of 10 cm. Out of 38 purse seine sets, made with 

 a net 540 m long, 67 m wide, and mesh size of 10 cm, 10 

 were successful and the maximum catch exceeded 10 t 

 in one instance. The catch was composed mainly of 

 schools of E. af finis and A. thazard. Figure 43 shows the 

 locations of the purse seine sets, catch per set, and sizes 

 caught. Silas noted that the average weight of A. rochei 

 was only 0.168 kg compared with an average of 0.750 kg 

 for A. thazard. Of these early attempts at tuna purse 

 seining in Indian waters, Sileis remarked that they were 

 not highly successful because the sinking rate of the net 

 was too slow thus allowing the schools to escape. Also, 

 he noted that the crew lacked experience in purse sein- 

 ing, but the failures, he felt, should not deter further at- 

 tempts at purse seining. 



In Sri Lanka, five types of gear are used to exploit 

 tuna — longline, po\e and line, trolling line, drift net, and 

 beach seine. The longline is used for Ifirge, deep- 

 swimming tunas and will not be discussed here. The re- 

 maining four are used in varying degrees to catch Auxis. 



The beach seine is not a selective gear for Auxis; 

 therefore, the catch by this gear is insignificant 

 (Sivasubramaniam 1965, 1973). Beach seining, requir- 

 ing about 30 men to conduct successfully, is possible in 

 places like Tangalle, Udapu, and Trincomalee, because 

 schools of Auxis occasionally migrate close (within 0.9 

 km) to shore. 



The most important method of capturing Auxis off Sri 

 Lanka, however, is by trolling. The gear is adapted from 

 salmon trolling gear and is unlike the standard tuna 

 trolling gear used extensively by Japanese and United 

 States fishermen (Sivasubramaniam 1965). Consisting 

 of three mainlines each with 30 branch lines which end 

 in jigs, the trolling gear is well suited for Sri Lanka's 

 waters because of the denseness of the schools of Auxis 



49 



