U. Our tagging data indicate that 

 there is an exchange of albacore 

 between the three major north 

 Pacific fisheries. This may mean 

 that we are dealing with one pop- 

 ulation in the North Pacific. 



CALIFORNIA BLUEFIN TUNA 



In general, the smaller 12- to 25- 

 pound bluefin are taken off southern 

 California throughout the season while all 

 sizes are found farther south. During the 

 past warm water year (1958) , however, 

 larger bluefin have moved northward, as 

 evidenced by the size composition of the 

 catch. 



The bluefin tuna fishery is a seasonal 

 one, and occurs between southern Baja 

 California and Point Conception. Practi- 

 cally the entire catch is landed in south- 

 ern California. The bluefin catch, like 

 the albacore, is subject to tremendous 

 fluctuations, the largest of which are 

 caused by varying market conditions. Our 

 data indicate that the abundance of blue- 

 fin tuna has remained high while availa- 

 bility, and fishing intensity have varied 

 greatly. 



Our conclusions are: 



1. We have found no measurable evi- 

 dence of overfishing. 



2. Our fishery is influenced pri- 

 marily by market conditions. 



3. Changing sea surface temperatures 

 affect the movements of bluefin 

 tuna, especially the larger fish. 



42 



