Gradient 



Stream gradients appeared to be an important factor influencing 

 sculpin distribution within the study area. Sculpin were found 

 at sites with stream gradients from less than 1% to 7% (Figure 

 7). In general, both sculpin species were more likely to be 

 found at sites with approximately a 3% to 4% stream gradient. 

 Sculpin were not found at sites with gradients exceeding 7%. 



Slimy sculpin were found in stream gradients ranging from 2% to 

 6%. 81% of the sites containing slimy sculpin had a 3% or >3% 

 stream gradient. Approximately 19% of the sites containing 

 slimy sculpin had stream gradients of 2%. 



Torrent sculpin were found at sites with stream gradients ranging 

 from less than 1% to 7% (the widest range) . The majority of 

 sites containing torrent sculpin (73.9%) had a 3% or >3% stream 

 gradient. Roughly 22% of the sites containing torrent sculpin 

 had a 2% or <2% stream gradient. 



Stream Order 



The sampling frequency for each stream order was dictated by the 

 concentration of each stream order in the watershed network, as 

 well as by seasonal factors. The majority of the sample sites 

 occurred on 3rd and 4th order streams. Most 1st and 2nd order 

 streams were either too small to electroshock, exhibited too 

 steep a gradient, or were dry during this sampling season. In 

 addition, far fewer 5th and 6th order streams exist in the study 

 area. Therefore, the number of sample sites for these orders was 

 less than for smaller order streams. 



Sculpin were more likely to be found on 4th, 5th, and 6th order 

 streams than at sites on 2nd and 3rd order streams (Figure 8) . 

 There was a greater chance of finding sculpin at a given site as 

 stream order increased. Slimy sculpin were most common across 

 the 3 stream orders sampled, being present on 3rd through 5th 

 order streams. Torrent sculpin were found at sites on 3rd, 4th, 

 5th, and 6th order streams. 



16 



