42 



were found in backwater habitats and younger age classes were typically located in lateral 

 sections of runs and riffles whereas the older age classes were found in higher current 

 velocities more characteristic of the center of the stream channel. In addition, it is not 

 apparent how sculpin species partition themselves at sites where they occur in sympatry. 

 As a result, sampling methods restricted to D-nets may yield data which does not accurately 

 reflect sculpin distribution or habitat use. 



The kick-screen proved to be ineffective at sampling sculpins. Sculpins washed against 

 the screen were capable of swimming into the current to escape being caught. Observations 

 of nets used to block the downstream end of a reach being electroshocked for population 

 estimates rarely yielded sculpins. However, trout were commonly found washed against 

 the net by the current. Perkinson (personal communication) attributes this to the different 

 effect of the electroshocker on trout and sculpins. Therefore, extending the length of the 

 screen to block the entire width of the stream, much like a block net or seine net, is not 

 likely to be any more successful. 



Hauer and Stanford (1981) developed a kick-net for sampling benthic 

 macro invertebrates in large river environments. This method might prove effecdve for 

 sampling sculpins. This sampling device has a large tent shaped net supported by two 

 handles anchored to the substrate. The deep pocket effectively traps aquatic organisms 

 swept by the current. But, as was noted with D-nets, the kicknet technique would also bias 

 sampling because it's effectiveness is limited to habitat with higher current velocities. 



Minnow traps proved to be ineffective sampling devices for sculpins. However, this 

 sampling method may prove to be useful with the proper bait to attract sculpins. Benthic 

 macroinvertebrates were chosen because the literature lists this as the primary food source 

 for sculpins. Additional studies need to be conducted on the use of minnow traps before 

 this method is considered ineffective. 



