Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

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

Publication Information

View PDF (554 KB)

Title: Capture, marking, and enumeration of juvenile bull trout and cutthroat trout in small, low-conductivity streams

Author: Bonneau, Joseph L.; Thurow, Russell F.; Scarnecchia, Dennis L.;

Date: 1995

Source: North American Journal of Fisheries Management. 15: 563-568.

Publication Series: Scientific Journal (JRNL)

Description: Relative efficiencies of sampling methods were evaluated for bull trout Salvefinus confluentus and cutthroat trout Oncorhynchus clarki in small, high-gradient streams with low conductivities. We compared day and nighttime observations by snorkelers to enumerate bull trout and cutthroat trout, and at night we also used a bank observer. Methods were developed for capturing juvenile bull trout in areas where traditional methods such as electrofishing were ineffective. Juvenile salmonids were counted during the day and night in two reaches (200 m) of Trestle Creek, Idaho, in August 1991. In July 1992, juvenile salmonids were counted during the day and night in 10 reaches (75 m) of three Idaho streams: Trestle, Rattle, and Granite creeks. Night counts of juvenile bull trout exceeded day counts in all reach comparisons; differences were significant (P < 0.05) in 1992 but not in 1991. In contrast, summer day counts of cutthroat trout were significantly higher (P < 0.05) than night counts when reaches were pooled in 1991, but no differences were found in 1992. Observations from the bank sometimes improved the accuracy of the population estimates; more than one-third of the juvenile bull trout observed in Trestle Creek in 1992 were observed from the bank, whereas bank observers saw fewer fish (both species) than snorklers in Granite Creek. Both snorkelers and bank observers effectively captured juvenile bull trout with specially designed nets at night. The snorkeler captured 71% of the juvenile bull trout observed, whereas the bank observer captured 86%. Visible polymer implants allowed us to identify marked fish at night without the need for recapture.

Keywords: bull trout, Salvefinus confluentus, cutthroat trout, Oncorhynchus clarki, sampling methods

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.

XML: View XML

Citation:


Bonneau, Joseph L.; Thurow, Russell F.; Scarnecchia, Dennis L. 1995. Capture, marking, and enumeration of juvenile bull trout and cutthroat trout in small, low-conductivity streams. North American Journal of Fisheries Management. 15: 563-568.

 


 [ 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.