THE HALIBUT FISHERIES 123 



Otherwise the gut cavity or ''poke" soon develops sour off-odors during 

 storage. Ample ice is placed around the halibut, with care being taken 

 to provide extra ice adjacent to the sides of the vessel and the bin parti- 

 tions. This practice avoids exposure of the halibut to the air as the ice 

 melts and the development of ''bilgy" spoilage in the flesh next to the 

 wood. 



As discussed earlier, a major portion of the North Pacific halibut is 

 taken from grounds which are 3 to 6 days' voyage from the landing port. 

 When this distance is added to the vagaries of weather and fish distribu- 

 tion, it can be readily seen why halibut are landed commonly from 8 to 

 16 days after catching. Fish from the earlier catches may still be of 

 reasonably good quaUty, but must be used promptly or frozen. 



The careful handling and icing by the fishermen are most important 

 in assuring the maximum retention of quality and, within a limited sense, 

 are more important than the time factor. Data from one group of landings 

 show little direct relation between the icing period for the oldest halibut 

 and per cent of the fish graded second quality because of soft, sour, and 

 yellow fish I 



Refrigerated Sea Water. Experimental tests^ have indicated that fish 

 held in refrigerated sea water (RSW) at 31°F are somewhat fresher than 

 comparable fish held in crushed ice for the same period. Both the exten- 

 sive experiments and commercial trials with bottom fish and halibut, 

 however, have brought out disadvantages of the RSW method. Objec- 

 tionable factors have been the large build-up of blood and slime in the 

 brine, loss of slime from the skin, difficulty in later handling, increased 

 salt content of flesh, weight gain of fish because of water absorption, 

 softer texture, changes in appearance, problem of segregating fish of vary- 

 ing ages in a few large tanks, and reluctance of buyers and graders to 

 handle the RSW fish. In view of these problems, little expectation is 

 held that the RSW method provides the solution to the basic problem 

 of extending the keeping quality of halibut from distant fishing grounds 

 aboard the fishing vessel. Rather, the RSW system should be considered 

 primarily for use in fisheries close to port with emphasis on the flexibility 

 and labor-saving aspects of the system. 



Improved Preservation Methods. In studying the extension of keeping 

 quality for chilled halibut, the use of preservatives in the ice or in refrig- 

 erated sea water has been considered experimentally^". Of various pre- 

 servatives, antibiotics, particularly chlorotetracycline, have shown the 

 most promise. Halibut, as with fresh fish generally, reflects a modest 

 improvement in quality or storage life if held in antibiotic ice under 

 experimental conditions. Experience with preservative ice formulas in 

 the last two decades has shown repeatedly, however, that the value of 



