ICES ad hoc Working Group on Interaction between Grey Seal Populations and Fish Species

The grey seal Halichoerus grypus is found in temperate and sub-arctic waters on both sides of the North Atlantic (Figure 1). It is a gregarious species, forming large concentrations on land during a generally well defined breeding season. There is great sexual disparity in size, the full-grown male weighing about 350 kg, nearly twice as much as the female. Sexual behaviour is highly developed, the dominant males defending loosely defined territories among the breeding females. The pup is suckled by the female for at least two weeks, increasing its weight nearly threefold during this time. The female generally remains with the pup until it is weaned and then, after mating, returns to the sea.