Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (108 KB)

Title: Physical, biotic, and sampling influences on diel habitat use by stream-dwelling bull trout

Author: Banish, Nolan P.; Peterson, James T.; Thurow, Russell F.;

Date: 2008

Source: North American Journal of Fisheries Management. 28: 176-187.

Publication Series: Scientific Journal (JRNL)

Description: We used daytime and nighttime underwater observation to assess microhabitat use by bull trout Salvelinus confluentus (N = 213) in streams of the intermountain western USA during the summers of 2001 and 2002. We recorded fish focal points and measured a set of habitat characteristics as well as habitat availability via line transects. Bull trout were benthic and solitary; most (88%) were observed at night. We developed a conditional logistic regression model to account for the effect of fish movement in response to snorkeling, and we fitted 18 candidate models to evaluate the relative influences of biotic and abiotic factors on habitat use. The candidate models were also fitted with a naive logistic regression (i.e., no movement) to evaluate the effects of movement on inferences of microhabitat use. The most plausible model describing bull trout habitat use was the same for the conditional and naive regressions and included depth, velocity, percent rubble substratum, and the day x depth, body size x depth, and body size x day x depth interactions. The presence of brook trout S. fontinalis and the abundance of conspecifics did not strongly influence microhabitat use by bull trout. The relative rankings of the remaining models differed substantially between the conditional and naive models. Relative to the conditional models, the naive models overestimated the importance of diurnal differences in habitat use and overestimated the use of deepwater habitats, particularly during the day. Both model types suggested that all sizes of bull trout were generally found in deeper, low-velocity habitat at night, whereas small bull trout (70-90 mm total length) were found in shallower habitats during the day. We recommend that biologists account for fish movement in response to sampling to avoid biasing modeled habitat use patterns by bull trout.

Keywords: bull trout, Salvelinus confluentus, sampling

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.



Banish, Nolan P.; Peterson, James T.; Thurow, Russell F. 2008. Physical, biotic, and sampling influences on diel habitat use by stream-dwelling bull trout. North American Journal of Fisheries Management. 28: 176-187.


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.