Unique diet and Philonema sp. infections in reservoir‐rearing juvenile Chinook Salmon.

This article focuses on how reservoirs created by dams influence the diet, growth, and parasite infection of juvenile Chinook Salmon (Oncorhynchus tshawytscha) in the Willamette Valley Project (WVP) reservoirs, Oregon. The study found that juvenile Chinook Salmon in Lookout Point Reservoir exhibit high rates of piscivory, primarily consuming young-of-year nonnative centrarchid fishes, which likely supports their rapid growth during summer and fall. Additionally, a high prevalence (34.6%) of infection by the parasitic nematode Philonema sp. was observed, with infection positively associated with consumption of zooplankton and fish and negatively associated with time, suggesting potential parasite-related mortality. These findings highlight complex biotic interactions in reservoir habitats that may both enhance growth and increase mortality risks for juvenile Chinook Salmon, underscoring the need for further long-term studies to assess population-level effects.