Long-tailed Duck, Clangula hyemalis, is a species of seaduck found in river and lake, coastal and shelf ecosystems.

Clangula hyemalis has a breeding population size of 2400-3800 pairs and a breeding range size of 52900 square kilometres in the EU27. The breeding population trend in the EU27 is Unknown in the short term and Unknown in the long term.

The EU population status was based on the winter data for this species. Clangula hyemalis has a winter population size of 1220000-2280000 individuals in the EU27. The winter population trend in the EU27 is Decreasing in the short term and Decreasing in the long term.

The EU population status of Clangula hyemalis was assessed as Threatened, as the species meets one or more of the IUCN Red List criteria for threatened at the EU27 scale.