APPENDIX A 



SUGGESTED SAMPLING SCHEME 



YELLOWSTONE RIVER MICROFLORA 



Loren L. Bahls 

 April 15, 1974 



Objective : 



To determine the basic characteristics of the periphytic and plank- 

 tonic components of the Yellowstone River microflora prior to potential 

 massive development of Fort union region coal deposits. 



Methods : 



Plankton : Although it is doubtful that the Yellowstone has a true 

 self-sustaining phytoplankton community, dislodged members of the peri- 

 phyton community, together with bits of detritus, other microorganisms 

 and drifting aquatic insects may be significant as a food source to such 

 filter feeding components of the ecosystem as the paddlefish. 



For collecting plankton, the small net described on pp. 239-241 of 

 Welch's Limnolgical Methods may be used. No. 25 standard silk bolting 

 cloth is the grade usually used, however this or a coarser mesh size 

 (greater than 64 microns) may not trap many of the smaller algal forms, 

 particularly the diatoms. 



The net should be suspended or towed in the current a minimum of 

 5 minutes or until several cubic centimeters of material are collected. 

 The sample should be adequately labelled and may be preserved in a 5 

 percent solution of commercial formalin. 



Periphyton: The periphyton community is probably much more im- 

 portant from the standpoint of primary production in the Yellowstone. 

 This community consists of sessile algae, including diatoms, growing on 

 the mud, rocks, logs or higher plants of the river bed. 



Collecting periphyton is simple but care must be exercised to get 

 a representative and composite sample. Algal growths are scraped with 

 a carefully cleaned pocket knife from whatever substrates on which they 

 happen to occur. Substrates (mud, rocks, logs and higher plants) should 

 be sampled in proportion to their importance at a given station. Also, 

 the sample should be roughly representative of different habitat types 

 (pool, riffle and run) present in the river at or near the station. 

 Extra care and effort may be required to locate and sample the not-so- 

 conspicuous diatom growths that may appear as gelatinous brown masses 

 feeling slimy to the touch. No attempt need be made to get a quantita- 

 tive sample. 



Alternative to the above sampling procedure, a small amount of 

 periphyton may be scraped from Dendy plant type samplers if such are 

 used concurrently for invertebrate collection. Other artificial (glass 

 or plastic) substrates may be used for periphyton collection if desired. 



All periphyton collections from one station on one date may be 

 mixed in a single bottle, labelled, and preserved with a 5 percent 

 solution of commercial formalin. 



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