446 MARINE PRODUCTS OF COMMERCE 



Alhacore {Germo alalunga): This is the first species canned in California and 

 the only one which can be labeled as white meat tuna. The pack of this species 

 was greater than all the others combined until 1925, when, for some unknown 

 reason, the catch declined and has never come back. 



Bojiito (Sarda chiliensis) : This species has a flesh that is somewhat darker in 

 color and stronger in flavor than the others. It ranges, in considerable number, 

 as far north as Alaska. 



Yellowtail {Seriola dorsalis) : This species is canned to some extent in Mexico, 

 but the canning of those caught in Californian waters is prohibited. It ranges south 

 from California to the Galapagos Islands. 



Fishing Methods. The tuna fishery has become a year-round fishery; with large 

 refrigerated "clippers" it is possible to range several thousand miles in search of 

 fish. During July, August, and September fishing is usually done near the coast 

 of California, and during the remainder of the year the vessels range farther. 

 The smaller vessels which do not make long cruises use crushed ice as a re- 

 frigerant. 



The tuna vessel is an especially constructed type, 65 to 145 feet in length, fitted 

 with radar, loran, radio direction finder, automatic pilot, depth-sounding devices, 

 and radio telephone. The capacity of the vessels ranges from 40 to 450 tons of 

 tuna, with a cruising range of several thousand miles. They are equipped to fish 

 with hook and line and purse seines. The purse seines are responsible for a con- 

 siderably greater portion of the catch than the hook and line. 



When the vessel using the hook and line method sights a school of tuna, live 

 bait, small pilchard, or anchovies are thrown overboard from the bait tank. Fisher- 

 men stand on a specially designed rack and fish with lines and barbless hooks. 

 When the tuna strike the hook, they are thrown on board by the heavy pole and 

 are released by the barbless hook as soon as they land on deck. The hooks are 

 made in the form of a lure, called "squid" or "jigs." If the fish are particularly large, 

 2 or 3 men work as a team on one hook. 



Purse-seine fishing does not require the use of bait since the school of tuna 

 is surrounded by the seine and held near the vessel. The fish are dipped from 

 the seine with a power-operated dip net. They are loaded through deck plates 

 into chilled brine in tanks in the hold of the vessel. When the fish have been 

 chilled to the temperature of the brine, the brine is pumped overboard. The fish 

 are then completely frozen by the refrigeration coils in the tanks. They are held 

 frozen until landed at the canning plant. The purse-seine method of fishing has 

 resulted in an increase in the production of tuna since it is possible to fish even 

 when small pilchard or anchovy bait are unobtainable. 



Delivery at the Canning Plant. On arrival at the cannery wharf the fish are 

 unloaded by hoisting them from the hold of the vessel in large metal buckets or 

 boxes. These are dumped into flumes which carry the fish to the scale house 

 where their weights are taken and recorded. The crews of the vessel are paid 

 according to the weight of the catch. After being weighed the fish are conveyed 

 into the cannery by flume. 



The tuna must be defrosted before they are canned. Crystals of ice formed 

 in the flesh of the fish when it is frozen cause damage unless defrosting takes 

 place slowly. Several methods are in use for defrosting. The water of the flume 

 removes some of the frost. In some plants the tuna are placed on the floor at 



