Session E5: Considerations and Alternatives for Safe Downstream Passage of Juvenile and Adult Sturgeon at Hydro Projects
Location
Groningen, The Netherlands
Event Website
http://fishpassage.umass.edu/
Start Date
23-6-2015 3:15 PM
End Date
23-6-2015 3:40 PM
Description
Abstract:
Fish passing downstream through hydro turbines may be subject to mortality rates between 5 and 30%, depending on species, fish size, and turbine design and operation. Juvenile and adult sturgeons may encounter multiple hydro projects during seasonal downstream movements and, consequently, some populations can be susceptible to potentially high rates of turbine passage and mortality. Although most downstream fish passage technologies have been evaluated with a wide variety of freshwater and diadromous fishes, relatively few studies have been conducted with sturgeon species. Turbine passage mortality typically is mitigated through the use of physical screening devices that reduce entrainment and guide fish to alternative downstream passage routes. Several lab and field studies have investigated guidance and exclusion of sturgeon exposed to various configurations of narrow-spaced bar racks and louvers, with effectiveness typically being dependent on bar spacing, structure angle to flow, and approach velocity. Bypass design and location are also important to passing sturgeon safely downstream. Laboratory data suggest bypass entrance velocities should be about 1.5 m/s or greater to effectively attract and pass sturgeon. For fish that pass through turbines, there is evidence that sturgeon may be less susceptible to injury and mortality than many teleost species. This is likely due to their tough integument, lack of scales, and cartilaginous skeleton, all of which probably contribute to lower rates of blade strike mortality. A review of recent studies examining downstream passage alternatives for sturgeon will be presented, as well as assessments of total project survival that account for passage route selection and associated mortality rates. With this information, the need for and feasibility of downstream passage facilities for sturgeon can be evaluated and used to develop appropriate mitigation measures.
Session E5: Considerations and Alternatives for Safe Downstream Passage of Juvenile and Adult Sturgeon at Hydro Projects
Groningen, The Netherlands
Abstract:
Fish passing downstream through hydro turbines may be subject to mortality rates between 5 and 30%, depending on species, fish size, and turbine design and operation. Juvenile and adult sturgeons may encounter multiple hydro projects during seasonal downstream movements and, consequently, some populations can be susceptible to potentially high rates of turbine passage and mortality. Although most downstream fish passage technologies have been evaluated with a wide variety of freshwater and diadromous fishes, relatively few studies have been conducted with sturgeon species. Turbine passage mortality typically is mitigated through the use of physical screening devices that reduce entrainment and guide fish to alternative downstream passage routes. Several lab and field studies have investigated guidance and exclusion of sturgeon exposed to various configurations of narrow-spaced bar racks and louvers, with effectiveness typically being dependent on bar spacing, structure angle to flow, and approach velocity. Bypass design and location are also important to passing sturgeon safely downstream. Laboratory data suggest bypass entrance velocities should be about 1.5 m/s or greater to effectively attract and pass sturgeon. For fish that pass through turbines, there is evidence that sturgeon may be less susceptible to injury and mortality than many teleost species. This is likely due to their tough integument, lack of scales, and cartilaginous skeleton, all of which probably contribute to lower rates of blade strike mortality. A review of recent studies examining downstream passage alternatives for sturgeon will be presented, as well as assessments of total project survival that account for passage route selection and associated mortality rates. With this information, the need for and feasibility of downstream passage facilities for sturgeon can be evaluated and used to develop appropriate mitigation measures.
https://scholarworks.umass.edu/fishpassage_conference/2015/June23/57
Comments
Presenting Author Bio: Steve Amaral is a Principal Fisheries Biologist with Alden Research Laboratory, Inc., located in Holden, Massachusetts. He has B.S. and M.S. degrees in fisheries biology, both from the University of Massachusetts. For more than 20 years, Steve has been extensively involved in the design, evaluation, and application of fish passage and protection technologies at all types of water intakes. He has participated in laboratory and field testing with various screening technologies, angled bar racks and louvers, and behavioral guidance systems. In addition to upstream and downstream passage, Steve’s hydropower experience includes instream flow assessments and turbine passage survival evaluations for conventional and hydrokinetic projects. He has lead investigations of injury mechanisms experienced by fish passing through turbines and has assisted with the development of theoretical models for predicting turbine passage survival. Much of Steve’s fish passage experience has included studies with endangered or threatened species, including American eel, shortnose and lake sturgeon, and Atlantic salmon.