Sensitivity of survival to migration routes used by juvenile Chinook salmon to negotiate the Sacramento-San Joaquin River Delta

摘要: Populations of juvenile salmon emigrating from natal rivers to the ocean must often traverse different migratory pathways that may influence survival. In regulated rivers, migration routes consist a network channels such as in Sacramento-San Joaquin River Delta, or passage structures at hydroelectric dams (e.g., turbines spillways). To increase overall survival, management actions systems focus on altering routing fish divert them away low-survival and towards high-survival routes. Here, we use 3-year data set route-specific survival movement Chinook Delta quantify sensitivity changes two major river junctions Sacramento River. Our analysis revealed response one junction depended not only differences among alternative routes, but also other junction. Diverting route downstream increased population by less than expected, given difference because part used an upstream We show will likely alter both provides analytical framework help fisheries managers suite maximize increases level