Fluvial aquatic ecology of the Colorado River (…especially Lees Ferry)
Jeff Muehlbauer with Ted Kennedy, Charles Yackulic, and many others
Grand Canyon Monitoring and Research Center Southwest Biological Science Center U.S. Department of the Interior U.S. Geological Survey A conceptual model
. How the ecosystem “works”
Unpublished data, subject to change, do not cite 2 A conceptual model
. How the ecosystem “works”
My talk: Bugs, light, shear stress, HFEs
Unpublished data, subject to change, do not cite 3 A conceptual model
. How the ecosystem “works”
Charles’ talk: Nutrients
Unpublished data, subject to change, do not cite 4 A conceptual model
. How the ecosystem “works”
Ted’s talk: Bugs, flows, fish
Unpublished data, subject to change, do not cite 5 Project 5
. Studies all life stages
. Identifies drivers / constraints of insects
. Estimates food availability for fishes
. Describes feeding habits of fishes
Unpublished data, subject to change, do not cite Lees Ferry drift research
Invertebrate drift: . Entrainment of bugs in water column . Critical life stage/behavior Food for fish . Mmm, drifting bugs…
Unpublished data, subject to change, do not cite 7 Drift in space
. Shear stress effects on drift (longitudinal) 80
60 ) 2 40
(N/m 20
Shear stress 0
20 ) 3 10
(#/m 0 Midge drift
River mile
Unpublished data, subject to change, do not cite 8 Drift in space
. Increasing drift with distance from Dam (longitudinal)
Unpublished data, subject to change, do not cite 9 Lees Ferry sticky trap monitoring
. ~ Every mile monthly: Dam to Lees Ferry
. Began Nov. 2013 . Capture adult aquatic insects
. Effective monitoring tool for food base?
(No, this is not Lees Ferry)
Unpublished data, subject to change, do not cite 10 Light effects?
. Fishermen notice hatch patterns at Ferry
. Strong light pattern in LCR
Unpublished data, subject to change, do not cite 11 Lees Ferry sticky trap monitoring
Channel orientation River mile (longitudinal)
Not much of a pattern… Unpublished data, subject to change, do not cite 12 Lees Ferry sticky trap monitoring
Seasonal . Strong phenological pattern
. Peaks in June . Very little Aug. to Mar.
. See larger patterns, IF they exist
Unpublished data, subject to change, do not cite 13 Lees Ferry sticky trap monitoring
Year-to-year . Stable year-to-year
. But is that “good”? . Let’s come back to this…
Unpublished data, subject to change, do not cite 14 Lees Ferry drift monitoring
. Monthly every ~ 3 miles, Dam to Lees Ferry
. Now a long-term dataset (~ 10 years)
. Mid-2016: Ferry to Badger Rapid too
. Let’s look at HFE effects!
Unpublished data, subject to change, do not cite 15 Spring HFE improved food base
Unpublished data, subject to change, do not cite 16 Fall HFEs do not improve food base
Spring HFE Fall HFE
Unpublished data, subject to change, do not cite 17 2012-15: Trout target midges and snails
What we expect them to eat
What they actually eat
Unpublished data, subject to change, do not cite 18 Summary
. Sticky traps: cheap, effective monitoring tool
. Drift: Good 2008-11, tanking since 2012 . Spring HFE: Good for bugs . Fall HFEs: Neutral to bad
. Only a few bugs to eat
. A house of cards…
Unpublished data, subject to change, do not cite 19 Go fish!
. Tailwater invertebrates of Glen Canyon and Flaming Gorge Dams
. Full deck: Flaming Gorge
. Clubs only: Glen Canyon Dam
Unpublished data, subject to change, do not cite 20