Table 4. Relative abundance of cells and rank by biovolume of 

 diatoms and genera of non-diatom algae in periphyton 

 samples collected from the Shields River in 2000. 



Taxa 



Relative Abundance^ and (Rank) 

 Station 1 Station 2 



Chlorophyta (green algae) 

 Ankistrodesmus 

 Cladophora 

 Closterium 

 Cosmari um 

 En t eromorph a 

 Oedogonium 

 Pediastrum 

 Scenedesmus 

 Selenastrum 

 Staurastram 

 Ulothrix 



common ( 5 ] 



common ( 3 ) 



occasional (7) 

 common (4) 



common ( 8 ) 

 occasional (4) 



rare (14) 

 occasional (11) 

 common ( 6 ) 

 abundant (2) 



common (9) 

 frequent (7) 

 occasional (12) 



common (5) 



Chrysophyta (golden algae) 



Diatoms frequent (2! 



dominant ( 1 ) 



Cyanophyta (cyanobacteria) ^ 



Merismopedia rare (8) 



Oscillatoria abundant (1) 



Phormidium occasional (6) 



common (10) 

 abundant (3) 

 occasional (13] 



^ d = dominant; a = abundant; f = frequent; c = common; o = 

 occasional; r = rare 



Formerly known as blue-green algae. 



