CRUISE 6608 

 AUGUST 1966 



▲ 



Mini 



YELIOWFIN TUNA 



SKIPJACK TUNA 



BOTH TUNA SPP. 



SURFACE TEMPERATURE, °C. 



REDCRAB, >40ML./10'M.^ 



SURFACE CHLOROPHYLL, > 0.2 MG./M.^ 



IIB-W. 



28° 

 N. 



27" 



26° 



25° 



24° 



23° 



22° 



Figure 8. — Distributions of surface temiierature, surface clilorophyll a, and red crabs for cruise 6C08 and 



locations of contemporaneous tuna catches. 



effort (nine boat-days) in one 1° square, bounded 

 by lat. 26° and 27° N. and long. 114° and 115° W., 

 took no tuna in tlic month of the cruise. According 

 to figure 8, nearly all of this area was either colder 

 than 20° C. (the northeastern corner) or had less 

 than 40 ml./l,000 m.^ of red crabs at the time of 

 the cruise. It would not, therefore, be expected 

 to contain many tuna. Elsewhere the distribution 

 of tunas at the time of the cruise is not known. 

 Fishing effort was not significant in the area of 

 high concentration of red crabs in the southwest- 



ern part of the cruise area, where temperature and 

 food were suitable for tunas. 



CRUISE TO-59-2 



This cruise, made August 16-29, 1959, was in 

 a warm year (see fig. 1), and the results represent 

 conditions at a later stage in the year than those 

 for the previous cruise. The cruise started farther 

 south than the others in this series; the area im- 

 mediately to the north was covered at the same 

 period by CalCOFI cruise 5908 which yielded 



DISTRIBUTION OF TROPICAL TUNAS OFF WESTERN BAJA CALIFORNIA 



163 



