Throughout its range the species is sedentary or locally dispersive, with northerly populations also making strong migratory movements (Billerman et al. 2020). The species frequents both coastal and inland habitats (Brown et al. 1982, Johnsgard 1993, Snow and Perrins 1998, Nelson 2005, Billerman et al. 2020). In marine environments it occurs in sheltered coastal areas on estuaries (Billerman et al. 2020), saltpans, coastal lagoons (Johnsgard 1993, Billerman et al. 2020), deltas (Johnsgard 1993) and coastal bays (Brown et al. 1982), requiring rocky shores, cliffs and islets for nesting (Billerman et al. 2020) but generally avoiding deep water and rarely extending far offshore (Snow and Perrins 1998). It also inhabits fresh, brackish or saline inland wetlands (Nelson 2005) including lakes, reservoirs, wide rivers, flood waters (Billerman et al. 2020), deep marshes with open water, swamps and oxbow lakes (Johnsgard 1993), requiring trees, bushes, reedbeds or bare ground for nesting (Billerman et al. 2020) and avoiding overgrown, small, very shallow or very deep waters (Nelson 2005). The species's diet consists predominantly of fish, including sculpins, Capelin, gadids (Gremillet et al. 2004) and flatfish (Leopold et al. 1998) as well as crustaceans, amphibians (Billerman et al. 2020), molluscs and nestling birds (Brown et al. 1982). At sea the species preys mostly on bottom-dwelling fish, occasionally also taking shoaling fish in deeper waters (Billerman et al. 2020).

Although the generation length for both EU and Europe regional assessments were calculated using the same methodology, new information arriving after the EU assessments were undertaken gave rise to an update in the generation lengths. This new information was then used for the Europe level assessments giving rise to a difference between the generation lengths used for the EU and Europe regions.

Conservation Actions Underway
The species is listed under the African Eurasian Waterbird Agreement. The species occurs in 242 Important Bird Areas. Within the EU it is listed in 245 Special Protection Areas.

Conservation Actions Proposed
Continued monitoring of population control measures.