stream size/drainage area & discharge (lotic- 

 connected vs. lentic-ponded-unconnccted 

 conditions), and the human-factor, stock pond/fish 

 species introductions. Increasing drainage area 

 directly relates to increasing fish diversity 

 (Anucrmeierand Schlosser 198Q. Brambictt et al. 

 2005), sshich is evident in the greater number of 

 expected indicator species in our fish assemblages 

 for the medium and larger prairie river systems. 

 Clearly, measures of connectivity are important in 

 structuring fish communities (Matthews and 

 Robison 1998. Bramblett and Fausch 1991 ). Many 



fish, even warmwater species (e.g. sauger, channel 

 catfish), arc migrator) during their spawning 

 periods ( I lolton and Johnson 2003 ) or pioneering 

 (e.g. white sucker, shorthead redhorse) and will 

 opportunistically search for suitable habitats. If the 

 conditions are fa\orable for fish species to migrate 

 into a particular type of aquatic system, especially 

 if connectivity is complete across the basin or there 

 is connectivity to reservoirs or other pools of non- 

 native fishes, then the community observed might 

 be surprisingly different than what was expected. 

 This explains white suckers co-occurring w ith 



Table 7. Fish and macroinverlehrale species. IBI s. MT MM! s and Observed/ Expected (O/E) 

 scores for the Slim Butte (SD) study sites. Bold-underlined score are good-excellent reach 

 scores, shaded gray represent fair-good local-reach conditions. 



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