Shelton and Hutchings Ocean stability and anchovy spawning in southern Benguela Current region 



331 





01 I 02 I 03 I 04 I 05 I 06 I 07 I 08 I 09 I 10 , 11 



. '2 , 



AUGUST 1977 



= 10 msec" 



^ vfe^ 



I 13 I 14 I 15 I 16 I 17 I 18 I 19 I 20 I 21 I 22 I 23 I 24 I 



l^m.. 



23 , 24 I 25 I 26 I 27 I 28 



29 I 30 



31 



^ 



01 I 02 I 03 I 



DECEMBER 1977 



JANUARY 1978 



^i^^MMi^^hglkM 



teSi^^M,^^ 



I 04 I 05 1 06 I 07 I 08 I 09 I 10 I 11 I 12 



1 1 = 10 m sec 



13 I 14 I 15 I 



JANUARY 1978 



Ffgure 8 



Wind stick diagram for the period 23 December 1977-15 January 1978 and 1-24 August 1977, showing tyical summer and winter patterns 

 of wind stress measured at the lighthouse at Cape Point, South Africa. 



values are generally much lower and more dispersed 

 over the west coast between Cape Point and Cape Col- 

 umbine in the absence of the surface front in winter. 

 A section on the west coast off Lambert's Bay (Fig. 

 7) shows a moderately strong thermocline with coastal 

 upwelling in simimer. Moderate-to-high levels of micro- 



plankton and chlorophyll-a extending to the limit of the 

 grid in the top 50 m are t>'])ical of the area at this time. 

 In winter the thermal structure is similar, but wath less 

 upwelling activity and cooler water offshore. Although 

 microplankton levels were low in the section shown, 

 widespread moderate levels of chlorophyll-o are quite 



