Ecorcgion: Nonlicm Great Plains Steppe 



Aquatic Ecological System Type: C005-Northwestem Great Plains Perennial Stream 



Key Environmental Factors: Hydrology — upstream beaver dams; Grazing — slight impacts; 

 Geomorphology — incised channel, unconsolidated substrate 



Rare or I niquc Species: Iowa darters were documented at the downstream end of reach. 



Rare Features: Dead sheep hanging in a tree near top of reach, shows hydrologic extremes (Figure 40) 



Introduced/Exotic Species: Dominated by Black bullhead and green sunfish 



Overall Ecological Site Condition: Poor/Fair 



Reach Summary : The 300 m reach consisted of 1 long pool complex with the uppermost 1 00m of the 

 pool being deepest and most incised (Figure 39). There were some areas of submerged aquatic 

 vegetation that provided most of the Hsh holding habitat, but unconsolidated knee-deep silt and chest-deep 

 ( I -1 .5m) channel depths made seining difficult. This stream reach has been overtaken by introduced 

 species and the aquatic habitat is not conducive to a typical C005 fish community (e.g.. no stable 

 substrate). All substrate of the pools was silt dominated with some clay. Riparian vegetation was 

 dominated by shrubs & grasses, but there were a few dying cottonwoods on (he right bank (Figure 39, 

 40). Aquatic vegetation and overhanging banks provided the most significant stream habitat in this stream 

 reach. Livestock use index (LUI) was moderate with -20 cow pies counted on a 75m walk of the left 

 bank. Pugging and hummocking was especially noticeable in the lower pool area where the cows have a 

 stream crossing. 



Reach Riparian Ranking: BLM= 50% (12 of 24) EPA RBP= 47.5 % (97 of 200) 



Reach Riparian Geomorphology: The geomorphology of this stream reach is a Rosgen G-6 with a 

 gentle slope (-0.5%), moderate sinuosity, an unstable, degrading run-pool configuration w iih 

 unconsolidated, erodible substrate dominated silts and clays. Pools are moderately incised and averaged 



>75 cm in depth, wetted width of the reach was 4.5m. Surrounding fine bank materials are similar to the 

 channel bed materials and riparian \egetation needs to be den.se to pro\ ide bank stabilization (I- igure 39). 



.Amphibian Community: 1 adult Northern Leopard Frog (NLF) present in the uppermost pool. 



Fish Community: 5 fish species (3 native) were seined in the 300m pool complex. Dominant species 

 were fathead minnows and black bullheads. Expected fish for this stream type would be fiathead chubs, 

 plains minnows and sand shiners so the expected community was not met. 



Fish Community Quality: IBN 34.9 0/E= 38.7% of expected fish community. 



Macroinvertebratc Community: This community was dominated b\ the intermittent prairie stream 

 invertebrates ot the i'rairie Pool assemblage (« 12. Stagliano 2005). liie comnuinil> indicator species 

 should have contained members oflhe Prairie Stream macroinvertebrates (^9 Stagliano 2005). Only 40% 

 of the indicator species were present in this sample. 



Miuroinvertebrate ( ommunit> Quality: M I MMN22.3 O/E=40% of expected macro community. 



38 



