A ▲ 



• .A*^ \ N^ — ~;P0INT SAN EUGENIO"- 



▲ •* 



LSAN PABLO POINT 



CRUISE TO-59-2 

 AUGUST 1959 



iililll 



YELLOWFIN TUNA 



SKIPJACK TUNA 



BOTH TUNA SPP. 



SURFACE TEMPERATURE, °C. 



RED CRAB, >40ML./I0'M.^ 



SURFACE CHLOROPHYLL, > 0.05 MG./M.' 



28" 

 N. 



27" 



26° 



25" 



24" 



23° 



22" 



Figure 10. — Dl.stril)utions of surface tenii>erature, surface chlorophyll a, and red crabs for crui.se TO-59-2 



and locations of contemporaneous tuna catches. 



The area where red crabs were over 40 ml./l,000 

 m.^ shows the same close but not exact correspond- 

 ence with the chloropliyll-rich area that was 

 found on previous cruises, and all the tuna catches 

 were made in or very close to this area. The high- 

 est concentrations of carnivores (tuna) , herbivores 

 (red crabs), and plants (chlorophyll a) all were 

 in the same restricted area. Because all tempera- 

 tures were suitable for tunas, the tunas occuri-ed, 

 as before, not only around but through the food- 

 rich areas. 



CRUISE TO-66-1 



The cruise period in the area of interest was 

 November 4-21, 1966. The cruise (figs. 13 and 14) 

 included stations with numbers below 15 and above 

 70, which were occupied on behalf of another in- 

 vestigator and were all north of lat. 28° N. 



As I expected, conditions were much more uni- 

 form throughout the area on this cniise than on 

 any of the others, because coastal upwelling had 

 ceased. The only inshore pocket of cool water. 



166 



U.S. FISH AND WILDLIFE SERVICE 



