Big Spring Creek below Casino Creek (3) . An oily residue 

 covered everything in this sample. The soft algae were in poor 

 condition. About 3 0% of the diatom cells were empty. The sample 

 was preserved with formalin. 



Big Spring Creek below Lewistown (1) . This sample was 

 partly decomposed and smelled of hydrogen sulfide when opened on 

 August 6. The soft algae were in poor condition and were covered 

 with a taupe (gray /brown/green) colored organic flocj. An oily 

 residue remained on the slide and coverslip after the sample was 

 wiped off. About 10% of the diatom cells were empty. 



NON- DIATOM ALGAE 



The non-diatom algal flora was similar above and below the 

 spill (Table 4) . Diatoms and the filamentous green algae 

 Cladophora and Ulothrix were present at all four of the sites. 

 The desmid Closterium was common in Casino Creek and in Big 

 Spring Creek both above and below Casino Creek. 



■ Some differences did occur, however. The filamentous green 

 algae Spirogyra and Zygnema were found in Big Spring Creek below 

 Casino Creek but not above Casino Creek or in Casino Creek 

 itself. The coenocytic chrysophyte Vaucheria was found only in 

 Big Spring Creek below Casino Creek. Oscillatoria , a filamentous 

 cyanophyte, was found only in Casino Creek. 



Phormidium, another filamentous bluegreen, was found only in 

 Casino Creek and in Big Spring Creek just below Casino Creek. 

 However, in an earlier assessment of Big Spring Creek (Bahls 

 1999) , Phormidium was found to be common throughout the upper 

 reaches of the stream above Lewistown. 



Not much can be made of these results because of the 

 perennial and persistent nature of some non-diatom algae 

 (especially Cladophora and Vaucheria) and the poor condition of 

 these samples. Diatoms, because of their solitary growth habit 



8 



