Entrainment of Juvenile and Adult American Shad at a Pumped Storage Facility

The American Shad Alosa sapidissima has been targeted for restoration to the upper Susquehanna River, and entrainment losses at hydroelectric facilities on the river, including the Muddy Run Pumped Storage Facility, are of concern for the potential growth of the American Shad population. Based on the integration of pumping volume, time of entrainment, and literature‐reported diel emigration of juvenile American Shad, the entrainment rate (N = 145; 53 exposed to pumping) was estimated at 3.5%. The entrainment rate for adults (N = 507) was estimated at 0.3–3.9%. Using multistate mark–recapture models, the estimated entrainment probabilities (Ψ) of radio‐tagged juveniles were higher during periods of extended pumping (>1 h; Ψ = 0.093; 95% confidence interval [CI] = 0.054–0.156) than at periods of no pumping or short‐duration pumping (