Environmental cues for downstream‐migrating American Eel at a hydroelectric facility.

This article focuses on identifying environmental factors influencing the downstream migration and passage of American Eels (Anguilla rostrata) from Roanoke Rapids Lake, a reservoir on the Roanoke River in North Carolina. Using acoustic telemetry over four migration seasons (2019–2023), the study found that eel out-migration probability was significantly associated with time of day (higher at night), rainfall, and hourly changes in lake level caused by hydropower operations. Predictive modeling indicated that declining lake levels, often linked to dam water releases, strongly stimulate eel migration, suggesting that managed water releases could be used to facilitate safer downstream passage through hydroelectric facilities. These findings contribute to understanding how dam operations affect American Eel migration and offer potential management strategies to improve eel survival during downstream migration.