24< 

 N. 



22' 



20" 



Yi GULF OF 



.MAGDALEN A } CALIFORNIA 



MEXICO 



MAZATLAN 



-*I2 



27 



1.42 JO 



.23 



'13 



SAN BENEDICTO I. 



J_ 



_L 



I4°W. 



112° 



110° 



108° 



106° 



Figure 37. — The surface currents determined by GEK measurements made on cruise TO-60-1. The arrows are vectorial 



and the figures give velocities in cm./sec. 



parallel to the coast off Lower California 

 persists, though it is less strong than it was 

 at 50 m. 



Inorganic phosphorus 



The distribution of surface inorganic phos- 

 phorus, not illustrated here, shows highest 

 concentrations (between 0.70 and 1.00 fig.- 

 at./l.) south of Cape Falso, and west from 

 the mainland coast north and south of Mazatlan, 

 although not west of Cape Corrientes. Lowest 

 concentrations ( < 0.40 /ig.-at./l.) are in the 

 extreme western and southwestern parts of the 

 station grid. 



Chlorophyll a 



The chart of standing crop of chlorophyll a 

 in the 0- to 100-m. water layer, which is not 



given here, shows some resemblance to the 

 chart of surface inorganic phosphorus. Con- 

 centrations over 20 mg./m.^ occur to the 

 south of the peninsula of Lower California 

 (highest values, > 70 mg./m.^, closest to the 

 coast) and west of the mainland coast between 

 Mazatlan and Cape Corrientes (again with 

 the highest values, > 30 mg./m.^ in this case, 

 inshore). Data are lacking from north of 

 Mazatlan. 



Measurements of primary productivity were 

 too few to permit any definite statements. The 

 highest values (integrations over the upper 

 40 m.) were in the south (stations 54, 58. and 

 60) where oxygen saturation was also high. 

 Values were intermediate at stations on the 

 next line north (46 and 42), and lowest at 

 stations still farther north (7, 25, and 31)-- 

 although station 20, at the end of a tongue of 

 upwelled water from Lower California, had 

 a high value. Data for chlorophyll a and 

 primary productivity have been listed else- 



42 



