Harbour seal / Common seal

The harbour seal is the most common seal species in Icelandic waters. It is considerably smaller than the grey seal and can be recognized by its shorter snout. There is little difference in size between the sexes. Males weigh on average 100 kg and are slightly heavier than females, which average 90 kg. Male and female lengths are on average 1.7 m and 1.6 m respectively. Coat colour can vary considerably according to season, sex and age. Females are longer-lived than males and can survive for more than 30 years.

The harbour seal is one of the most widely distributed seal species in the world. Their diet consists mainly of cod, but also redfish, sand-eel, pollock, herring, Atlantic wolffish, capelin and flatfishes. It’s an accomplished diver and can stay under water for up to 25 minutes. Most often, it feeds at the depth of 10-50 m but can dive to 200 m or more for short periods.

Harbour seals are social and can often be seen in groups by the shoreline, although rarely in winter. Females congregate in haul-out sites in spring and give birth to one pup, which they lactate for 4-6 weeks. Harbour seal colonies are thought to have evolved as protection against predation. Males come to the haul-out sites in early summer. During the rut they compete for mating access to females and try to attract the females with various gestures. Dominant males will successfully breed with a number of receptive females and pups are born in the following spring. During the winter, males and females rarely mix, and younger animals are seldom seen with older ones.

Previously, harbour seals were more common in Iceland. From 1972 to 1978 the Icelandic population was estimated at 43 000 animals. However, in both 2006 and 2011 the population was estimated at 12 000. According to a count in 2014, numbers were down to approximately 4 000 individuals. These figures reflect a reduction in harbour seal numbers of more than 90% over the past four decades.