5/13/13 – 007 Goes on a Mission!

5/13/13 – 007 Goes on a Mission!

“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 operates a series of antenna arrays in the Willamette system.  “007” showed up as at Leaburg Dam (RM 40.0) on 3/1/2013; lingering in the area for about 6 hours.  We got lucky since our transmitters are only active for 2 days per week – he just happened to be passing the antenna when his transmitter was on.   He had previously last been seen on 2/1 at RM 20.8. Our trackers located him this past week (5/10) at RM 23.1 – back in the study section!  This means that “007” made a remarkable round trip of at least 36 miles in less than three months!  He may well have gone further as we did not pick him up on our telemetry flight on 4/21. We located our other usual suspects this past week in a float from Taylor’s Landing (RM 28.2) to Bellinger (RM 19.0). See who’s where with Follow Our Fish! We kicked off the 4th year of the Mark & Recapture Study on May 1, and early returns from anglers have been good, with several nice rainbow trout caught and lots of action on dry flies.  Stay tuned for...
4/30/13 – 2012 Mark & Recapture Population Study Reports Online!

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

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 Population Study: 2012 Final Report (PDF, 0.7mb) 2010 – 2012 Distribution of Wild Trout, Aerial Photo & Map (PDF, 14.5mb) 2010 – 2012 Distribution of All Fish, Maps (PDF, 0.3mb) Read more about the Mark & Recapture...
2013 Kickoff Meeting – April 30th, 6:00pm

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

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 calendars and join us for the kickoff of the 2013 Lower McKenzie River Wild Trout Population Study! Dave Thomas will be presenting our 2012 end-of-season report, with maps and preliminary population estimates for the first three years of the study. Arlen Thomason and Scott Kinney will discuss the progress and ongoing findings from the Radio Telemetry Study. The 2013 Mark/Recapture (Floy-tagging) study season will begin on May 1st and continue through the end of June. For those of you who haven’t fished the study section lately, we’ve seen dramatic improvements in the fishing since our first season. In 2010, we averaged about 3 wild trout per trip; in 2011, about 6; and in 2012, we saw almost ten wild trout landed per trip! This spring is shaping up to be the best fishing in years, with low water, warm temperatures, good hatches, and limited snowpack. Whether you can spend one day or twenty on the water, we’d love to have your help! All volunteers for the 2013 season will need to have completed the ODFW Floy-tagging training. ODFW staff will be offering Floy-tagging training after the meeting for new volunteers and previous participants who want a refresher course. If you attended a training meeting in 2010, 2011, or 2012, attendance is not required. That’s not all! We’ll be awarding prizes for 2012, and discussing exciting new prizes for 2013! Please contact redside@mckenzietroutstudy.org or shannon.e.richardson@state.or.us if...
Factors Affecting Angling Productivity in a 5.1 Mile Section of the McKenzie River

Factors Affecting Angling Productivity in a 5.1 Mile Section of the McKenzie River

Interested in why fish bite some days and not others? So were we!  One of the side benefits of a rigorous sampling program like we have for the Five-Year Mark & Recapture Study is that we now have robust, quality-checked datasets to ruminate on!  The 2010-2011 dataset includes over 1,400 angler hours on the river, and some 1,000 fish events.  Since our data is date-specific, we can (and have!) associated it with date-specific environmental variables. We did preliminary exploration of the dataset using the following variables: Productivity variables – the ones we wanted to try to get to the bottom of! Bull trout productivity (fish per angler hour) Chinook salmon smolt productivity (fish per angler hour) Wild cutthroat trout productivity (fish per angler hour) Wild rainbow trout productivity (fish per angler hour) Hatchery rainbow trout productivity (fish per angler hour) Steelhead smolt productivity (fish per angler hour) Whitefish productivity (fish per angler hour) Tagged fish (wild cutthroat + wild rainbow) productivity (fish per angler hour) Total productivity, all species (fish per angler hour) Environmental variables – a cross-section of weather, flow, and temperature variables which speak to common conceptions of when fish tend to bite: Trip Data: Day of calendar year (indicator of early versus late in the season) Number of anglers in boat Names of anglers Total trip time Flow: CFS at Walterville Daily mean Day-over-day (1-day) change Day-over-day (1-day) trend (rising/falling/steady) 3-day moving average 3-day average change 3-day trend (rising/falling/steady) 10-day moving average 10-day average change 10-day trend (rising/falling/steady) CFS at Vida Daily mean Day-over-day (1-day) change Day-over-day (1-day) trend (rising/falling/steady) 3-day moving average 3-day average change 3-day trend (rising/falling/steady) 10-day moving...
End of 2012 Mark & Recapture Study Season

End of 2012 Mark & Recapture Study Season

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 the ODFW crew (Jeff, Kelly, Shannon, Matt) for a day of electrofishing on the Hendricks-Bellinger stretch. The ODFW driftboat contains a generator which powers two ‘squids’ at the end of retractable poles.   The squids are outset slightly from the front of the boat.  The electrical current stuns the fish, which come up to the surface.  Two people in the front of the boat have dip nets and gather up the fish.It all seems simple enough, until you add in the dimensions of moving water, confined space, 10’ long nets, fish that are only stunned for a very brief instant, and loud noise of the generator which makes communication nearly impossible. It requires an impressive amount of skill on the part of the rower, as well as quick reaction from the dipnetters.   Jeff manned the sticks for the entirety of our two runs.  The four of the rest of us rotated on net for the first run (the other two following in my boat).  Kelly and Shannon went back to the office for the second run, leaving the greenhorns (Matt and myself) to learn on the fly. Our first pass down the left side of the river yielded only a half-dozen or so trout that met the 150mm criteria.  The second run down the right bank was more productive, and we ended up with 25ish trout in the book,...