Available data for the American Eel (Anguilla rostrata) indicate that, overall, there have been declines in recruitment, population, and escapement during three generations (36 years). A recent report indicated that barriers to migration (dams and weirs), passage through turbines at hydropower dams, habitat degradation or loss, and overharvest were likely the greatest threats by humans across the species’ range. Although eels are able to ascend many smaller barriers, recent studies have documented a tenfold reduction in eel density above each potentially passable barrier. For example, the number of juvenile eels migrating to Lake Ontario passing over hydropower dams fell from 935,000 in 1985 to approximately 8,000 in 1993 and, finally, [...]
