PEARCY: ALBACORE OCEANOGRAPHY 



Figure 20. — The proportion of squids, 

 fishes, and crustaceans (on a weight 

 basis) in the stomach contents of 

 albacore caught by the Cciyuse, 

 27 July-2 August 1970. Numbers 

 indicate the number of stomachs 

 examined. "S" denotes where saury 

 made up over 50% of the biomass 

 of stomach contents. 



127* 



126' 



125* 



l24' 



Figure 21. — The proportion of squids, 

 fishes, and shrimps (on a weight 

 basis) in 6-ft Isaacs-Kidd midwater 

 trawl tows to 100-m depth at night, 

 27 July-2 August 1970. The total 

 biomass of these groups combined 

 for each tow is proportional to the 

 logarithm of the diameter of the 

 circles. 



I I I I I II I I I I I I 



I I I M I 



123' 



MIDWATER TRAWL CATCHES 



® e 



€ 



o 



(!) 



© 



® 



.« 





b^«§^ 



129" 



L±. 



I I I I I I I I I I I I I I I I I I I I 



125' 



123' 



the area where saur}^ had been eaten several 

 days before. 



Highest albacore catch rates also occurred 

 where albacore were feeding on saury. All 

 catch rates were ranked from highest to 

 lowest for locations where food data was 

 available (see Figures 19 and 20). The sum 

 of the ranks was then compared for areas 



where saury predominated (>50% of the stomach 

 biomass) and where saury did not predominate 

 stomach contents. Catch rates were signifi- 

 cantly higher in areas where sauries pre- 

 dominated stomach contents than in areas 

 where saury were not predominant. (Mann- 

 Whitney IJ Test, P<0.01. »i 9, no 9). The 

 decreased albacore catch rate after 28 July 



501 



