194 



V. Alexander et al. 



TABLE 5-4 List of Common Epipelic Algae Species Found in Pond B in 1972* 



Cyanophyta 



Anabaena lapponica 

 Aphanocapsa sp. 

 Aphanotheca clathrata 

 Aphanotheca sp. 

 Aphanozomenon flos-aquae 

 Chroococcus turgidis 

 Coelospherium kuetzingianum 

 Gleococcus schroeteri 

 Gomphospheria naegeliana 

 Microcystis flos-aquae 

 Gomphospheria sp. 

 Oscillatoria agardii 

 Oscillatoria sp. 

 Synechocystis notatus 



Chlorophyta 



Ankistrodesmus falcatus 

 Ankistrodesmus spirale 

 Chlamydomonas frigida 

 Chlamydomonas lapponica 

 Chlamydomonas sessila 

 Closterium aciculare 

 Closterium moniliferum 

 Cosmarium bo try t is 

 Cosmarium granatum 

 Cosmarium ornatum 

 Elakatothrix lacustris 

 Euastrum binale 

 Euastrum elegans 

 Oocystis lacustris 

 Staurastrum gracile 



Bacillariophyceae 

 Cymbella sp. 

 Eunolia lunaris 

 Fragilaria virescens 

 Fragilaria sp. 

 Navicula sp. 

 Nitzschia linearis 

 Pinnularia mesolepta 

 Pinnularia sp. 

 Stauroneis sp. 

 Tabellaria fenestrata 



Chrysophyta 



Pseudokephyrion undulatissimum 

 Synura uvella 



Pyrrophyta 



Amphidinium sp. 

 Peridinium inconspicuum 



Cryptophyta 



Cryptomonas sp. 



Euglenophyta 

 Lepocinclis sp. 



*Identifications by C. Coulon. 



algae are very different from the dominant planktonic algae (Chrysophyta, 

 Cryptophyta). 



Most of these cells are very small (<10Mm) so that in 1971, for 

 example, even though their numbers ranged from about 2x 10^" to 4x 10'" 

 m"^ the equivalent carbon biomass was calculated to be only 0.5 to 1.0 g 

 m "^ (Figure 5-10). The pattern of gradual seasonal increase in the biomass 

 was repeated in Pond A in 1973, where Fenchel (1975) found a change 

 from 2.5 to 8x 10" cells m ~^. Although the numbers Fenchel obtained in 

 1973 are higher than the numbers in Figure 5-10, his estimate of algal 

 biomass (700 mg C m^^) agreed very well with the 1971 estimates. 



There is considerable variation in the abundance of algae, measured 

 by the chlorophyll a concentration, from pond to pond. For example, Pond 

 B sediments contained almost twice as much chlorophyll as those from 

 Pond Din 1972 (Table 5-5). 



