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.

Who?

As of the 2013 season, 108 different volunteer anglers have participated in the study.

What?

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.

When?

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

Where?

The study section includes Hendricks Wayside to Bellinger Landing (river mile 24.1 – 19.0).

Why?

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.

How?

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.

Lower McKenzie Wild Trout Population Study: 2013 Final Report (PDF, 0.9mb)

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.

Lower McKenzie Wild Trout Population Study: 2012 Final Report (PDF, 0.7mb)

2011 Study Reports

We’re proud to announce that our 2011 end-of-season reports are now available online.

Lower McKenzie Wild Trout Population Study: 2011 Final Report (PDF, 1.48mb)

Poster Presented at 2012 Oregon Chapter American Fisheries Society Annual Meeting (PDF, 1.3mb)

2010 Study Reports

We’re proud to announce that our 2010 end-of-season reports are now available online.

Lower McKenzie Wild Trout Population Study 2010 Final Report (PDF, 0.2mb)

Data Mapping

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)

2010 – 2013 Comparative Distribution of Rainbow Trout (PDF, 1.9mb)

2010 – 2013 Comparative Distribution of Cutthroat Trout (PDF, 1.7mb)

2010 – 2013 Comparative Distribution of Hatchery Trout (PDF, 1.6mb)

6/10/14 – 2013 Season Report & Maps
Read more Read more

A  big thanks to all of our volunteers – over 100 in all – who contributed over 2,500 hours to the study effort. Our volunteers caught over 1,900 trout and 1,100 other fish during the course of the study. This study would not...

6/5/14 – 2013 Season Wrap-Up Meeting
Read more Read more

Esteemed citizen scientists,I’m pleased to let you know that the long-rumored Trout Study wrap-up meeting is finally about to happen, surmounting a raft of logistical issues that led to the delay. The meeting will take place on...

6/10/13 – Finn is Alive!
Read more Read more

Our trackers floated from Hendricks to Bellinger on Friday, 6/8, and located eight fish, including Eeyore, Dasha, Sonya, Radio, Finn, Lenny, Waldo, and Wanda.   These fish haven’t moved much in the preceding several weeks.  Finn and...

6/4/13 – Updates!
Read more Read more

We’ve sent out tracking boats the past few weekends, and little has changed with the status of the tracked fish. We are still unable to locate the following: Nigel, Gil, Rusty, Dixie, Sven, Harvey, Ole, and Lloyd.  We do have good...

5/13/13 – 007 Goes on a Mission!
Read more Read more

“Where’d that fish run off to?” is a question we’ve been asking for several weeks now.  We located one of the missing fish this past week by reviewing fixed station data provided by the University of Idaho, who...

4/30/13 – 2012 Mark & Recapture Population Study Reports Online!
Read more Read more

In addition to expanding our reporting for the 2012 season, we’ve completed a comprehensive audit of the first three years of data.  Thus, these reports may be slightly different than those from previous years. Lower McKenzie Wild Trout...

2013 Kickoff Meeting – April 30th, 6:00pm
Read more Read more

McKenzie River Wild Trout Population Study 2012 Wrapup and 2013 Kickoff Meeting Tuesday, April 30th, 2013, 6:00PM Oregon Department of Forestry Conference Room, 3150 Main St., Springfield, OR 97478 (across from ODFW office) Mark your...

End of 2012 Mark & Recapture Study Season
Read more Read more

The end of the 2012 Mark & Recapture Study season was marked by two passes of electrofishing from the ODFW Springfield crew on August 8th, 2012.  Nearly 200 fish were captured over the course of the day. I had the pleasure of joining...