The continued increase in the consumption of tuna made it necessary 

 that canners "be assiored of a sufficient supply of raw material. The fleet 

 was increased in number and size of the individual vessels and more extensive 

 operations were carried on off the coast of Mexico, In 1927, for the first 

 time, the catch south of the Mexican hoimdary exceeded the production off 

 CsLLifornia, With this j'ear, the principal sjurce of fish for the California 

 canneries moved to the waters off Central and South ^erica. 



The day of the large "boats and long cruises was at hand. Msuiy changes 

 in methods of operation were made to increase the efficiency of the fishirig 

 vessels. Ice was carried in insulated fish holds so that the "boats coiald 

 remain at sea for longer periods, crews' quarters were enlarged to improve 

 living conditions, and diesel engines replaced gasoline engines to provide 

 additional power and increase safety and economy. By 1926, some vessels 

 were 110 feet in length, and were powered with 3OO H.P, engines, Tb.ese 

 larger vessels were designed to operate outside Mexican territorial waters 

 and Jhus avoid payment of Mexican duties. 



Japanese interests had begun operating for tuna in Mexican waters, 

 freezing the fish for shipment to Japaj?.. In 192^, heijause of a shortage 

 of fish, arrangements were made "by some California canners to p^irchase 

 tuna from the Japanese operating off Mexico. However, these p-urchases were 

 not large. In 1925, the first commercial imports of frozen buna were 

 received from Japan. Tlie shipment, totaling about 800,000 pounds, was the 

 forerunner of much larger receipts from Japan and other countries in the 

 future. 



As the California fleet of fishing vessels increased in size, they 

 were able to operate in southern waters where large concentrations of 

 skipjack and yellowfln were available throughout the year. The catch 

 continxied to increase, axid in 1930 exceeded 100 million poiinds for the 

 first time. As a result of the world-wide business depression and heavy 

 volume of frozen and canned imports of tiona from Japan, the catch fel3. sharply 

 to less than 60 million pounds in 1931 and then recovered slowly until 193^, 

 when the duty on tana canned, in oil, was raised from 30 percent to ^5 per- 

 cent ad valorefflo In 1935, the catch reached a new high of neaurly 125 icillion 

 poTinds. In the following years, the market for canned tuna continued to 

 expand, and further jjnprovements were made in the size, equipment and range 

 of the large ti^na clippers, which had become the backbone of the tujia fleet. 

 By 1937. methods had been developed for freezing the fish immediately aiCter 

 capttore in a brine solution. This permitted retention of the fish aboard 

 th« vessel in a solidly frozen condition for as long as it was necessary 

 to remain at sea. 



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