CRUISE TO-59-2 

 AUGUST 1959 



AUG. 29 



® 



NOON STATIONS 

 MIDNIGHT STATIONS 

 OTHER STATIONS 



28* 

 N. 



27" 



26" 



25" 



24" 



23" 



22" 



121° 



116°W. 115" 114" 113" 112° 111° 



FiouEE 9. — Track and station positions for cruise TO-59-2. 



110' 



109° 



face temperatures were about 1.5° C. lower in a 

 few inshore localities, and elsewhere about the 

 same as on TO-65-1 (Scripps Institution of 

 Oceanography, 1967). Even these lower tempera- 

 tures were over 20° C. and would not be expected 

 to affect tuna distributions ; therefore, all tuna oc- 

 currences for the whole period, September 8-25, 

 1965, have been given in figure 12. Data on red 

 crab concentrations are given in table 5. 



Surface chlorophyll a concentrations were all 

 below 1.0 and ranged down to 0.02 mg./m.^, al- 



though they were generally higher than on cruise 

 TO-59-2. The 0.2 mg./m.^ isogram encloses the 

 area of highest concentration, which is tonguelike 

 and originates on the coast south of Point San 

 Eugenio, as on previous cruises. It probably rep- 

 resents the biological result of a tongue of up- 

 welled water which can no longer be distinguished 

 from the surrounding water by its temperature. 

 All stations inshore of this tongue and tlie follow- 

 ing stations offshore had over 0.1 mg./ni.^: 4—6, 

 12, 13, 17, 23, 26-29, 32, and 36. 



DISTRIBUTION OF TROPICAL TUNAS OFF WESTERN BAJA CALIFORNIA 



165 



