Abundance 



37501- 



3222 



2250L 



1530L 



758L 



Biomass 



Abundance t 



3750L 



3003- 



2250L 



1533L 



750L 



Biomass 



L23 



1972 



Fig. 6.4 Pontoporeia affinis at stations 20 and 21. 



2 

 — Q— abundance (no./m ) 



2 

 —A— biomass (g/m~ ) 



105 



