CRUISE TO -65-1 

 SEPTEMBER 1965 



® 



116'W. 



PART 1 (SEPT. 8-20) 

 PART 2 (SEPT. 20-25) 

 NOON STATIONS 

 MIDNIGHT STATIONS 

 OTHER STATIONS 



HP 114° 113° 112' 111* 



Figure 11. — Track and station positions for cruise TO-65-1. 



27° 



26" 



25° 



24° 



23° 



22° 



110° 



the northwestern part of the cruise area shown in 

 figure 6. Elsewhere in all the charts, agreement is 

 fair to good. The area boundaries for the two 

 proi>erties seldom coincide, but they tend to lie 

 close together and to have the same shape. Where 

 the isograms of chlorophyll a follow those of tem- 

 perature, all three properties — temperature, 

 chlorophyll a, and red crabs — have a closely similar 

 distribution (e.g., fig. 10). 



The occurrence of red crab maxima with chlo- 

 rophyll a maxima is not surprising because red 

 crabs feed on phytoplankton, but the circum- 



stances whereby they maintain aggregations in 

 chlorophyll-rich areas are not altogether clear. On 

 the one hand, the distribution data of Boyd ( 1967) 

 and Longhurst (1967) indicate that the red crab 

 can be swept away from the coast by the California 

 Current during its pelagic phase. On the other 

 hand, substantial numbers of this species occur in 

 the benthos along the Continental Shelf and Slope 

 (Boyd, 1967) , and these individuals probably help 

 to maintain pelagic concentrations in coastal areas 

 by generating larvae and by ascending into the 

 upper waters from time to time. Larvae are most 



168 



U.S. PISH AND WILDLIFE SERVICE 



