Near-Field Interactions of Hydrokinetic Turbines and Fish

Environmental performance is a key consideration for siting, system selection, and deployment scale of proposed hydrokinetic power generation projects.  Stakeholders seek credible information that such projects are benign with regard to their effects on aquatic life.  Numerical modeling and laboratory flume studies of near-field interactions between hydrokinetic turbines and fish provide valuable insights into the potential for adverse effects of hydrokinetic energy projects on fish populations.  Passage studies in laboratory flumes recently conducted with rainbow trout (Oncorhynchus mykiss) and largemouth bass (Micropterus salmoides) at Alden Research Laboratory and with Atlantic salmon smolts (Salmo salar), and adult American shad (Alosa sapidissima) at the U.S. Geological Survey’s S.O. Conte Anadromous Fish Research Center indicate avoidance of turbines under the conditions tested.  Numerical modeling of strike probability and experiment-based estimates of mortality and injury rates of fish passing through the cross-sectional area swept by the turbines indicate strike-related injury rates are low.  96-hr survival estimates with 95% confidence intervals were between 98.4% ± 1.1% and 100.4% ± 0.8% depending on test conditions for rainbow trout exposed to a cross-flow type turbine and from 99.4% ± 0.7% to 101.6% ± 1.3% for trout exposed to a ducted, propeller type turbine.  96-hr survival estimates for largemouth bass exposed to the ducted turbine ranged from 99.6% ± 0.6% to 102.9% ± 2.9%.