Fish Passage
What is it?
Fish passage projects are restoring connectivity to streams impacted by physical or chemical barriers to fish and other aquatic organism movement. Barriers can include culverts, stream crossings, dams, water diversions, or other physical/chemical barriers. Barriers have been document to impede fish movement to spawning and nursery habitats, prohibit dispersal downstream, and cutoff gene flow between populations. Long-term impacts of barriers have been diminishing populations of migratory aquatic species driving many to an imperlied status and some to the point of extinction.
Conservation Benefits
- Maintains connectivity for aquatic organism migration
- Maintains connectivity for gene flow between aquatic organism populations
- Prevents changes in stream hydology and sediment flow
- Protects access to breeding and swaning areas
What does it include?
Fish passage projects are extremely diverse and will depend on the region, species involved, biology and life histories of impacted species, and stream hydrology and morphology. Common fish passage projects include
- replacing culverts
- redesigning stream crossings
- removing dams
- creating stream bypasses or fishways
- building fish ladders
Fish Passage Links
- National Fish Passage Program (US Fish and Wildlife Service)
- Conceptual fish passage designs & cost estimates for Lower Alameda Creek (Alemeda Creek Water District, Alameda Creek County Flood Control and Water Conservation District)
- Design for fish passage at road-way-stream crossings (US Department of Transportation)
- Design of road culverts for fish passage (Washington Department of Fish and Wildlife)
- Fish passages (NRCS)
- Fish passage design for road crossings (California Department of Transportation)
- Fish preservation and enhancement: fish passage and enhancement (Washington County DLUT)
- Maine Dept of Transportation Fish Passage policy and design guide (Maine DOT)
- Oregon Department of Forestry's Stream Crossing Monitoring Protocol: Fish Passage and Streamflow design (Oregon Department of Forestry)
- Overcoming barriers to fish passage: fish passage over large structure - rock ramp (Cooperative Research Centre for Catchment Hydrology)
- Overcoming barriers to fish passage: fish bypass channels (Cooperative Research Centre for Catchment Hydrology)
- Overcoming barriers to fish passage: fish passage through culverts (Cooperative Research Centre for Catchment Hydrology)
- Techniques: fish passage restoration (Washington State Aquatic Habitat Guidlines Program)
Fish Passage Bibliography
- Gibson et al. 2005. Loss of fish habitat as a consequence of inappropriately constructed stream crossings. Fisheries 30: 10-17.
- Helfrich et al. 1999. Influence of low-head diversion dams on fish passage, community composition, and abundance in the Yellowstone River, Montana. Rivers 7: 21-32.
- Jungwirth et al. 1998. Fish migration and fish bypasses.
- Northcote. 1998. Migratory behavior of fish and its significance to movement through riverine fish passage facilities. Fish Migration and Fish Bypasses pp. 3-18.
- O'Hanley and Tomberlin. 2007. Optimizing the removal of small fish passage barriers. Environmental Modeling and Assessement 10: 85-98.
- Schilt. 2007. Developing fish passage and protection at hydropower dams. Applied Animal Behavior Science 104: 295-325.
- Warren and Pardew. 1998. Road crossings as barriers to small-stream fish movement. Transactions of the American Fisheries Society 127: 637-644.