Five Year Mark & Recapture Study
The purpose of the study is to assess the effect of removal of hatchery fish on the native trout populations of the McKenzie River. Hatchery fish stocking was discontinued on this section of river in 2010. Quantitative information about native trout in the lower McKenzie River is limited and existing literature suggests that ceasing hatchery trout releases leads to increased wild trout populations due to reduced competition and angling-related mortality. The Lower McKenzie Wild Trout Population Study (LMWTPS) was initiated in 2010 and is ongoing. 2013 marks the fourth year of data collection.
As of the 2013 season, 108 different volunteer anglers have participated in the study.
The study intends to establish a baseline population of both wild rainbow and wild cutthroat trout, and track those changes over the course of a five-year period.
The study began in March, 2010, and will run through 2014. Fishing effort has been concentrated in the spring and summer. Angling dates: 2010: March 4 – June 25 2011: April 29 – July 8 2012: May 6 – August 1 2013: May 1 – June 29 Fall radio-tracking angling period: 2012: October 14-October 22
The study section includes Hendricks Wayside to Bellinger Landing (river mile 24.1 – 19.0).
Hatchery fish stocking was discontinued on this section of river in 2010. The purpose of the study is to assess the effect of removal of hatchery fish on the native trout populations of the McKenzie River.
Anglers (hook & line) and ODFW electrofishing crews fish for wild trout. For trout captured, species, fork length and location is recorded. Captured trout are tagged using uniquely numbered Floy® tags, held until recovered and released near the point of capture. For trout subsequently recaptured, the same information is recorded, with the fish released with the initial tag.
2013 Study Reports
The 2013 season confirmed the results of the first three seasons. The wild trout population in the study section has nearly tripled – with an estimated 2,143 fish per mile in 2013, up from 729 fish per mile in 2010.
2012 Study Reports
In addition to expanding our reporting for the 2012 season, we’ve completed a comprehensive audit of the first three years of data. These reports may be slightly different than those from previous years.
2011 Study Reports
We’re proud to announce that our 2011 end-of-season reports are now available online.
2010 Study Reports
We’re proud to announce that our 2010 end-of-season reports are now available online.
The following display fish capture location and fish size data mapped along rivercourse centerline, overlaid on USDA NAIP DOQ photographs.
2010-2013 Distribution of Wild Trout, Aerial Photo & Map (PDF, 48.5mb)
2013 Distribution of Wild Trout: Aerial Photo & Map (PDF, 10.0mb)
2012 Distribution of Wild Trout: Aerial Photo & Map (PDF, 9.6mb)
2011 Distribution of Wild Trout: Aerial Photo & Map (PDF, 11.1mb)
2010 Distribution of Wild Trout: Aerial Photo & Map (PDF 10.7mb)
The following display fish capture location for each species:
2010 – 2013 Comparative Distribution of Wild Trout (PDF, 1.9mb)