An Uncommon (yet necessary) Union
Integrating Engineering and Fisheries Biology
Chris Myrick
Fish, Wildlife, and Conservation Biology
Chris.Myrick@colostate.edu
Lecture Outline
• Instream flows
– Components of a
successful program
– Importance of flow
– Importance of 4dimensional connectivity
• 4-dimensional
Connectivity
– What happens if you
disconnect?
– Examples
– Can “disconnecting” be
useful?
• Introduction to fish
movement
– Velocity control
– Fish swimming velocity
ranges
• Measurement
– Fish jumping
• Measurement
• Fish passage options
– Fishway types
• Desired features
• Conclusions
Instream Flow & The Natural Flow Paradigm
“The main principle…is that flow regime is the
dominant variable in determining the form and
function of a river.”
Annear et al. 2004
“Managers…must recognize the importance of
inter- and intra-annual flow variability [to] enable
critical ecological processes”
Annear et al. 2004
Components of a Successful
Instream Flow Program
Ecosystem Components
• Riverine components
–
–
–
–
–
Hydrology
Biology
Geomorphology
Water quality
Connectivity 
• Policy components
– Legal
– Institutional
– Public involvement
Four-Dimensional Connectivity
• Connectivity: flows, exchange, and pathways
that move organisms, energy, and material
through a river system
• Connectivity is complex and interrelated
• River connectivity has four dimensions
–
–
–
–
Longitudinal
Vertical
Lateral
Temporal (time)
• Let’s focus on disruption of longitudinal
connectivity from an ecological standpoint
Why Connectivity Matters
• Because stream fish have
evolved in dynamic
environments, they take
advantage of, and depend
on, a variety of habitats
Movement to
spawn
Refugia from harsh
environmental conditions
(e.g., extreme
temperatures or flows)
with unfavorable growth
conditions
Movement to
refuge
Spawning
habitat with
incubation
of eggs
Movement to
feed
Movement to
spawn
Mosaic of feeding
habitat(s) with favorable
growth conditions
hab 1
Movement to
feed
Adapted from Schlosser and Angermeier 1995
hab 2
hab 3
Why Connectivity Matters
• Restore/maintain biophysical linkages + ecological
connectivity
• Allow up- and downstream movements of migrating
fishes, other organisms, energy, matter
– Fragmentation can lead to local extinctions & ecosystem
dysfunction
Riverine Fishes
Dams (big ones)
Waterfalls
Dams (even little ones)
Culverts
Flood-control Structures
More Flood-Control Structures!
Beneficial losses of connectivity?
• Yes…in a few cases
• Prevent upstream movement of invasive species
• Prevent loss of fish to water diversions or
hydroelectric turbines
Fish Swimming - Wave Propagation
Velocity Control
• Increase frequency of
undulations
• Increase amplitude of
undulation
• Increase surface area
acting (pushing) against
the water
Factors Affecting Swimming Velocity
• Species
– sedentary vs. active
• Size
– Large vs. small
• Water temperature
– Warm vs. cool
• Water quality
– Pollutants
– Dissolved oxygen levels
– Etc.
Fish Swimming Velocities
• Prolonged (> 1 hour)
• Sustained (1 h to 1
minute)
• Burst (< 1 minute)
• Measured using
swimming flumes (fish
treadmills)
Velocity vs. Endurance
Example of Swimming Experiments
How else do fish negotiate fishways?

v f  vs  d  E
Peake’s Equation
1
vs

Fishway Water Velocity (cm/s)
What can swimming studies tell us?
Burst
70
Prolonged
Sustained
60
50
40
30
20
10
0
0
10
20
30
Maximum Fishway Length (m)
40
• Fishway length and allowable velocities
– Peake’s Equation
• vf = water velocity in fishway
• vs = water velocity of swimming trial (fish swimming velocity)
• Evs = endurance at velocity vs
• d = maximum fishway length
• Remember, a fish moving upstream must exceed downstream velocity
Fishway Water Velocity (cm/s)
Brassy Minnow Example
Burst
70
Prolonged
Sustained
60
50
40
30
20
10
0
0
10
20
30
Maximum Fishway Length (m)
40
A Common Misconception!
A Situation To Avoid
Measuring Jumping Ability
• CSU has pioneered recent
work in this area
– Relies on the use of artificial
waterfalls with variable pool
depths and weir heights
– Mandi was one of the
developers of this technique
• Species jumped to date:
–
–
–
–
–
–
–
Brook trout
Rio Grande cutthroat trout
Colorado R. cutthroat trout
Fathead minnows
Brassy minnows
Common shiners
Arkansas darters
Fish Jumping Experiment
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
Typical Fish Jumping Results
0.8
0.7
0.6
0.5
0.4
Proportion
Successful
0.3
0.2
cm
60 cm
50 cm
40 m
c
30
20
cm
cm
Waterfall Height (cm)
0
10
10
20 cm
30 cm
40 cm
50 cm
60 cm
70 cm
80 cm
90 cm
cm
0.1
Pool Depth (cm)
Pool & Weir Fishway
Pool, Weir, & Orifice Fishways
Pool, Weir, and Orifice Fishways
John Day Dam fish ladder
Denil Fishways
Vertical Slot Fishways
Vertical Slot Fishways
Rock-Ramp & Nature-like Fishways
Rock Ramp & Nature-like Fishways
And the winners are…
• Rock-ramp fishways
• Vertical slot fishways
• Why?
– Operate over a wide
range of flows
– Allow fish to pass without
requiring jumping
– Are suitable for a wide
range of species w/∆
swimming abilities
What Makes A Good Fishway?
• Provide velocity refuges
• Access to all levels of
water column
• Work over a wide range of
flows
• Provides enough
attraction flows
• Works for a wide range of
fish sizes
• Allow structure to continue
hydraulic/engineered
function
What About Fish Barriers?
• Create a situation that
exceeds a fish’s
performance or
physically limits the
fish’s movements
• Drop-structures
(waterfalls)
• Screens
• Velocity barriers
Useful Tools
• Instream flow
techniques manuals
• Fish Xing 3.0 Software
– Fish passage through
culverts
• Coursework in fisheries
biology
– Fish Ecology
– Fish Physiology
– Ichthyology
Take-Home Messages
• We should (must) incorporate fishways in all
potential obstacles
• Effective fishways must work for most/all
species and a wide range of sizes
• Effective fishways have:
– good attraction flows
– velocity refuges
– ideal entrance configurations
• Engineers and biologists must learn to
communicate!
Take-Home Messages cont…
• Effective environmental engineers
– Have a basic understanding of fish biology and
fisheries management (FW300, FW400, FW401,
FW405/605, etc.)
– Consult with fisheries biologists during design,
implementation and monitoring phases of projects
• Effective fish biologists
– Have a basic understanding of environmental
engineering (CE413, G652, CE522, CE544, etc.)
– Consult with engineers during design,
implementation and monitoring phases of projects