Treated sewage released into rivers may hamper eel migrations

Discharges from sewage remedy vegetation into rivers might act as a barrier to migrating fish. European eels (Anguilla anguilla) appear to intentionally keep away from plumes of handled wastewater, in some circumstances delaying their journeys by a number of days.

Sewage remedy creates a posh chemical cocktail – “thousands and thousands of chemicals, and we don’t know the exact composition”, says Hendrik Volken Winter at Wageningen University within the Netherlands.

When finding out how hydropower or pumping stations delayed or killed migrating eels, his crew observed that …