39 



Land Use 



Each sculpin species was capable of tolerating some degree of land use disturbance 

 within the watershed. The most common form of water pollution resulting from these land 

 uses was sedimentation. It was beyond the scope of this study to judge the tolerance of 

 each species to various forms of disturbance. Most of the sites were impacted by the 

 cumulative effects of several upstream land use practices. 



Sculpin densities were noticeably impacted by land use at some sites. Sedimentation 

 caused by several forms of land use in the watershed at the lower site on Lake Creek made 

 the habitat basically inhospitable for sculpins. Torrent sculpins were rare at this site. Their 

 presence was limited to the rip-rap structures on the bank where interstitial spaces in the 

 large boulders offered suitable habitat. Mid-channel substrate at this site was heavily 

 embedded with sand and silt. Logging, roads, grazing, mining and channel structures 

 were all recorded in this watershed making it impossible to isolate a single factor impairing 

 the habitat. 



The near absence of sculpin species at undisturbed sites was more a reflection of the 

 lack of these pristine areas encompassing larger rivers as well as the limited number of 

 watersheds free of human disturbance rather than the attraction of sculpins to disturbed 

 sites. Undisturbed sites are typically located at higher elevations characteristic of low order 

 streams. Sculpins were generally found in streams of 3rd order and larger in this study. 

 As a result, sculpin presence at a particular site might be more associated with location in 

 the drainge rather than land use. 



Age Classification 



Brown (1971) estimated the approximate length of torrent sculpins for the first two 

 years as follows: 1 year - 3.3 cm; 2 years - 5.8 cm. The samples on Libby Creek were 



