Density of Flagellates and Myxophyceae 



225 



n. of 

 samples 



ro 9 .10 fo 29. .30 1-0 59. 60 to 120,121 fo 240, .3 00 to 1230, 

 Very poor 



17 



poor middle rafher rich rich Very rich 



£36 7H 49 14 3 



Fig. 2. Percentages of samples rich with Cijclococcolithus (black lines) or 

 with naked flagellates (dotted lines) for several categories of the seston 

 density, between and 1,230 cells/ml. It is clear that rich nannoplankton 

 does not coexist with poor seston, probably according to less dissolved or 

 suspended organic matters. 



