CHAPTER IV — DOMESTIC PRODUCTION 



ABSTRACT 



Of the 32 PERCENT OF WORLD PRODUCTION OF TUNA AND TUNALIKE FISHES ACCOUNTED 

 FOR BY UNITED STATES FISHERMEN, ALMOST ALL OF THIS AMOUNfT IS TAKEN ON THE PACIFIC 



COAST, Nearly all tuna clippers and about 15 purse seiners are used solely to 



FISH FOR tuna AND RELATED SPECIES,, OTHER CRAFT ENGAGED IN THE TUNA FISHERY ARE 

 ALSO OPERATED TO A LARGE EXTENT IN OTHER FISHERIES SUCH AS THOSE FOR SALMON, 

 HALIBUT, BOTTOM FISHES, PILCHARDS, ETC. 



SUPPLYING MECHANICAL EQUIPMENT TO THE TUNA FLEET IS A HIGHLY COMPETITIVE 

 FIELD INVOLVING OUTSTANDING FIRMS WITH HIGHLY TRAINED ENGINEERING STAFFS. ThC 

 ALMOST UNJVERSALLY-USED SLOW SPEED HEAVY DUTY MAIN DIESEL ENGINES ARE EXTREMELY 

 RELIABLE AND ECONOMICAL. REPLACEMENT OF THESE WITH HIGH SPEED DIESELS WOULD 

 RcSULT IN A REDUCTION OF WEIGHT AND A SAVINGS !N CARGO SPACE, BUT RE-TRAINING 

 OF ENGINEERS WOULD BE REQUIRED AND LaVER DEPENDABILITY MIGHT RESULT. SMALLER 

 TUNA VESSELS HAVING PROPORTIONATELY INCREASED CARGO SPACE THROUGH THE USE OF 



HIGH SPEED Diesels might result in more economical operations. Oiesel-electric 

 propulsion would provide greater flexibility and lowered maintenance costs, but 

 the inital cost might be double that of the present engines. 



There appears to be little prospect of improvement in conventional propellers. 

 The design of tuna vessels can be improved only at the cost of decreased carrying 

 capacity and effscsencv. primary fault of the ammonia compression refrigeration 



system, nearly universal !N the tuna fleet, may be lack OF ADEQUATE RESERVE 

 CAPACITY. The ammonia A3S0RPT!0N system has certain advantages, but TRIALS TO 



date have not been entirely successful due to imperfections in the system and 

 lack of trained engineers. hydraulic pumps and plastic piping offer possibilities 

 for lower installation and maintenance costs. 



Radar, loraWj and depth sounders have materially increased fish production 

 SINCE World War II. Development of new electronic devices such as echo-ranging 

 units and underwater listening equipment hold PROMdSE of greatly increasing 

 efficiency of fishing operations. Electrical fishing experiments conducted in 

 Europe on marine fishes indicate that the successful development of electrical 

 fishing equipmentt could revolutionize some methods of commercial fishing.. 

 Present fishing gear is effective and any change must prove of decided super ior- 

 iTYo Plastic or nylon netting might prove superior to cotton and linen for 

 purse seines. Gill nets can catch tuna and may be used as auxiliary gear. If 

 Americaivi fishermen can profitably use long-line gear, new fishing areas in the 

 east -central pacific may be opened up. 



The PRESENT TUf>IA BOATS ARE HIGHLY EFFICIEIVr AS OPERATED. UNLESS SOME REVOLU- 

 tionary means of catching tuna is developed to a practical stage there appears 

 to be little chance of curtailing production costs through increased effectiveness 

 per unit of crew effort. 



Bait is an important aspect of the United States tuna fishery, since 70 per- 

 cent OF THE TOTAL CATCH OF TUNA BY UNITED STATES VESSELS IS MADE WITH BAIT. JN 

 1950 ROUGHLY i POUND OF BAIT WAS NECESSARY TO TAKE llO POUNDS OF SKIPJACK OR 

 YELLaVFIN TUNA, AND A LESSER AMOUNn" FOR ALBACORE, AN ESTIMATED 26,000,000 POUNDS 



165 



