Non-Diatom Algae (Table 4) 



Twenty-two genera representing five divisions of non-diatom algae were found in 

 samples that were collected from tributaries of the Madison River in 2003 (Table 4). Divisions 

 represented by the most genera were Chlorophyta or green algae (12 genera) and Cyanophyta or 

 cyanobacteria (6 genera). The Division Chrysophyta (yellow-green algae) was represented by 

 two genera and the Divisions Rhodophyta (red algae) and Phaeophyta (brown algae) were 

 represented by one genus each. 



Cyanobacteria were found in all 10 samples and green algae were found in all but one 

 sample (Blaine Spring Creek belovv fish hatchery). Yellow-green algae were found in 5 samples 

 and were most abundant in Blaine Spring Creek. The red alga Audouinella was found only at the 

 lower Elk River site and the brown alga Heribaudiella was found only at the lower Gazelle 

 Creek site. The number of genera of non-diatom algae ranged from 2 near the mouth of Blaine 

 Spring Creek to 9 at the lower site on Elk River. 



Nitrogen-fixing Algae. Cyanobacteria that possess a certain type of specialized cell 

 (heterocyst) are capable of fixing molecular or atmospheric nitrogen under aerobic conditions. 

 These algae have a competitive advantage in waters where nitrogen is in short supply relative to 

 phosphorus and other nutrients. Among tributaries of the Madison River, algae with heterocysts 

 include Calothrix, Nostoc, and Tolypothrix. These algae were present in Antelope Creek, Elk 

 River, upper Gazelle Creek, Buford Creek, and Blaine Spring Creek at bypass. Nitrogen may be 

 the limiting nutrient at these sites. 



Mat-forming Filamentous Algae. Large standing crops of filamentous algae can 

 interfere with swimming, boating, fishing, and other water uses. Algal genera in tributaries of 

 the Madison River that are known to produce nuisance growths in North American waters are 

 Cladophora, Oedogomum, Oscillatoria. Rhizoclonium. Spirogyra, and Ulothrix (Wehr and 

 Sheath 2003). One or more of these genera were dominant or abundant only at the lower site on 

 Elk River, where Cladophora was abundant. Among sites in this sample set, this site is most 

 likely to support nuisance growths of filamentous algae. 



