An Uncommon (yet necessary) Union Integrating Engineering and Fisheries Biology Chris Myrick Fish, Wildlife, and Conservation Biology

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 “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 spawn Movement to feed Adapted from Schlosser and Angermeier 1995 hab 1hab 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 v f = water velocity in fishway v s = water velocity of swimming trial (fish swimming velocity) E vs = endurance at velocity v s d = maximum fishway length Remember, a fish moving upstream must exceed downstream velocity Peake’s Equation

Brassy Minnow Example

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

Typical Fish Jumping Results

Pool & Weir Fishway

Pool, Weir, & Orifice Fishways

Pool, Weir, and Orifice Fishways John Day Dam fish ladder

Denil 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