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An Uncommon (yet necessary) Union Integrating Engineering and Fisheries Biology. Chris Myrick Fish, Wildlife, and Conservation Biology Chris.Myrick@colostate.edu. Instream flows Components of a successful program Importance of flow Importance of 4-dimensional connectivity
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An Uncommon (yet necessary) UnionIntegrating Engineering and Fisheries Biology Chris Myrick Fish, Wildlife, and Conservation Biology Chris.Myrick@colostate.edu
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 Lecture Outline
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
Spawning habitat with incubation of eggs Movement to spawn Movement to feed Movement to spawn Mosaic of feeding habitat(s) with favorable growth conditions Refugia from harsh environmental conditions (e.g., extreme temperatures or flows) with unfavorable growth conditions Movement to refuge hab 1 hab 2 Movement to feed hab 3 Adapted from Schlosser and Angermeier 1995 Why Connectivity Matters • Because stream fish have evolved in dynamic environments, they take advantage of, and depend on, a variety of habitats
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
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
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)
Example of Swimming Experiments How else do fish negotiate fishways?
What can swimming studies tell us? Peake’s Equation • 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
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
Pool, Weir, and Orifice Fishways John Day Dam fish ladder
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