An Uncommon (yet necessary) UnionIntegrating Engineering and Fisheries Biology

Chris MyrickFish, Wildlife, and Conservation Biology

Chris.Myrick@colostate.edu

Lecture Outline• Instream flows

– Components of a successful program

– Importance of flow– Importance of 4-

dimensional 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

• Policy components– Legal– Institutional– Public involvement

• Riverine components– Hydrology– Biology– Geomorphology– Water quality– Connectivity

Ecosystem Components

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

Spawning habitat with incubation of eggs

Refugia from harsh environmental conditions (e.g., extreme temperatures or flows) with unfavorable growth conditions

Mosaic of feeding habitat(s) with favorable

growth conditions

Movement to spawn

Movement to refuge

Movement to feed

Movement to spawnMovement to

feed

Adapted from Schlosser and Angermeier 1995

hab 1 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?

What can swimming studies tell us?

• 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

€

vf=vs−d×Evs−1( )Peake’s Equation

0

10

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0 10 20 30 40Maximum Fishway Length (m)

Fishway Water Velocity (cm/s)

Burst Prolonged Sustained

Brassy Minnow Example

0

10

20

30

40

50

60

70

0 10 20 30 40Maximum Fishway Length (m)

Fishway Water Velocity (cm/s)

Burst Prolonged Sustained

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 aYUV420 codec decompressor

are needed to see this picture.

Typical Fish Jumping Results

10 cm20 cm30 cm40 cm50 cm60 cm70 cm

80 cm90 cm

10 cm20 cm30 cm40 cm50 cm60 cm

0

0.1

0.2

0.3

0.4

0.5

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Proportion Successful

Waterfall Height (cm) 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