Presentation on theme: "An Uncommon (yet necessary) Union Integrating Engineering and Fisheries Biology Chris Myrick Fish, Wildlife, and Conservation Biology"— Presentation transcript:
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 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 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
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
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
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
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