LAURS and LYNN: SEASONAL MIGRATION OF THUNNUS ALALUNGA 

 150° 145° 140° 135° 



48' 



45 c 



i — i — i — r 



i — i — r 



I j * 



~i — r 



130° 



125° 



120° 



115° 





40= 



AFRF CHARTER 

 FISHING VESSEL 

 CRUISE TRACKS 



1972 

 1973 

 1974 



48° 



35' 



30° 



25° 



V 



J 1 L 



J I L_L 





150° 



145° 



J I L 



J I i L 



- 1 L. 



"*0° 135° 130° 125° 120° 115 



FIGURE 3.— American Fishermen's Research Foundation charter fishing vessel cruise tracks for the 1 972-74 offshore research 



25° 



surveys. 



ry fishing before late May. Variations in distribu- 

 tion and relative abundance of albacore were ob- 

 served within and between surveys. 



Differences Between Surveys 



Plots of the charter vessel catches for each sur- 

 vey are given in Figures 4a-c. The catches rep- 

 resented in these and other plots have been stan- 

 dardized to the number of fish caught per 150 



TABLE 1. — Albacore survey catches. 



Year 



Total catch by 

 charter vessels 



Tagged and 

 released 



Total catch by 

 research vessel 



line-hours (averaged between pairs of vessels that 

 fished together for 1972 and 1973) and presented 

 graphically by proportionately increasing size of 

 dots. 



In 1972 and 1973, relative abundance of alba- 

 core was high between lat. 32°and 35°N, long. 135° 

 and 140°W, and lat. 32° and 35°N, long. 135° and 

 143°W, respectively (Figure 4a-b). In both of these 

 years small or no catches were made in the region 

 between long. 135°W and inshore waters within 

 150 mi of the coast where fishing takes place dur- 

 ing the traditional albacore fishing season. In 

 1974 (Figure 4c), high catch rates were again 

 made offshore of long. 135°W, but over a larger 

 latitudinal range, lat. 31° to 36°N, and somewhat 

 more scattered than in the two preceding years. 

 Also, high catches were made at about lat. 33° to 

 36°N, long. 124° to 135°W in the region between 



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