Harp seals are migratory and have a much wider distribution range than ringed seals, bearded seals, and walruses; they also have a more pelagic life history (Lavigne and Kovacs, 1988; Haug et al., 1994a). Three different populations inhabit the North Atlantic: the Northwest Atlantic population off Canada’s east coast; the Greenland Sea (West-Ice) population which breeds and moults just north of Jan Mayen; and the East-Ice population which congregate in the White Sea to breed.
Hooded seals form one stock in the Northwest Atlantic and another in the Northeast Atlantic; although, recent genetic studies suggest no biological distinction between the groups (Coltman et al., 2007). In the Northeast Atlantic, whelping takes place in mid-late March in the West Ice, not far from where the West-Ice harp seals give birth. Between breeding and the moult, hooded seals carry out feeding excursions to the continental shelf edge off the Faroe Islands and Northern Ireland and to areas in the Norwegian Sea.
Small cetaceans that frequent the Barents Sea include bottlenose dolphins, common dolphins, white-sided dolphins and white-beaked dolphins. All but the latter occur in the southern Barents Sea, particularly along the shelf break and over oceanic banks and ridges, but must be considered vagrants in the region. White-beaked dolphins are the only small cetacean species that routinely occupies the region more broadly.
Bearded seals have a patchy distribution throughout the Arctic, occurring at low densities throughout their range. They are largely solitary, but small groups can be seen during late spring and -early summer, when they are breeding,breed and then moultingmoult/molt, and the sea-ice cover is restrictedlimited. Bearded seals can maintain holes in relatively thin ice, but avoid densely packed ice unless open-water leads are available.
Among the toothed whales, the long-finned pilot whale, sperm whale, the northern bottlenose whale, and killer whales are summer visitors to the Barents Sea. The Northeast Atlantic population of long-finned pilot whales number some 780,000 individuals (NAMMCO 1998), but only a very small (and unknown) part of this population enters the Barents Sea. Few sightings have been made in areas covered by IMR surveys; these sightings are insufficient to estimate
Coastal marine mammal species in the Barents Sea include harbour seals, grey seals, and the harbour porpoise. Larger whales also migrate along the coast on their way north to the take advantage of the summer burst of productivity in the Barents Sea. The harbour seal is a coastal species that is found both in the Atlantic and Pacific Oceans. Harbour seals are gregarious, hauling out to rest on land at low tide every day of the year, in groups ranging from just a few animals up
Ringed seals occur throughout the Arctic. They are the only northern seal that can maintain breathing holes in thick sea ice and thus are distributed well beyond the range of the other northern true seals – north to the Pole (Heide-Jørgensen and Lydersen, 1998; Gorbunov and Belikov, 2008). They are extremely dependent on sea ice, which is their exclusive breeding and haul-out platform. Typically, they prefer land-fast ice in fjords and along coastlines, with reasonably thick
Killer whales occur in all world oceans and most seas, but their relative scarcity and sporadic occurrence make them difficult to census in the Barents Region. Photo-identification techniques have been used to recognise >400 individuals in northern Norway. Coastal killer whales are tightly linked to the availability of herring. During winter, killer whales aggregate in and around Vestfjorden in Lofoten, foraging on over-wintering herring.
White-beaked dolphins are the only dolphin to remain in the Barents Sea Region on a year-round basis. They are found throughout the North Atlantic, primarily in shelf waters, but they canmay also inhabit offshore areas of intermediate depths. During summer, they can be found north to the ice edge. They are commonly sighted in coastal waters around Spitsbergen in summer, as well as in the pelagic parts of the Barents Sea, but are most common in the southern Barents
Walruses are distributed across the circumpolar Arctic, but their distribution is discontinuous and two subspecies are recognized: one in the Pacific; and the other in the Atlantic. In the northern Barents Sea, they are found from Svalbard through to Franz Josef Land; in the southern Barents Region, they occur in the Pechora Sea and the Kara Sea. Recently, they have been observed regularly in the White Sea as well (Klepikovsky and Lisovsky, 2005; Svetochev and
Among the baleen whales that frequent the Barents Sea on a seasonal basis, the minke whale is the most numerous. Recent estimates suggest that the population is quite stable (Solvang et al., 2015), although minor variations do occur in both distribution and point estimates. The most recent point estimate for minke whale abundance in the total area is numerically lower than previous estimates, but not significantly different from estimates based on the two preceding
The bowhead whale is the only baleen whale that resides in the Arctic throughout its life. It is highly adapted to its ice-associated lifestyle, possessing a very thick layer of blubber (up to 30 cm), no dorsal fin, and a complex circulationcirculatory system (with numerous vascular retes) for conservingadaptations) to conserve heat. Moreover, their highly elevated blow-holesblowholes are thought to be an adaptation tofor breathing inwithin the cracks in sea ice.
Polar bears have a circumpolar Arctic distribution, which includes the entire northern Barents Sea south to Novaya Zemlya. They are heavily dependent on sea ice for foraging and for travelling to and from terrestrial denning areas; they depend on thick layers of snow in maternity denning areas. They prefer first-year ice that develops over shelf seas for hunting, where ice-associated seals (their primary prey) are most abundant (Derocher et al., 2002).
Fin whales and humpback whales are the second and third most abundant baleen whales in the Barents Sea, respectively. Both are fast-swimming, migratory species that over-winter in the south and occupy the Barents Sea during the productive summer months. The summer activity of these whales is dominated by feeding and during most of the winter; they are thought to fast while they are breeding. In the Barents Sea, fin whales generally inhabit deeper areas along
Narwhal inhabit the North Atlantic Ocean sector on both sides of Greenland and the archipelagos of, as well as Svalbard and Frans Josef Land archipelagos. They also occupy some waters north of Canada and Russia; they are very rare in the Pacific Arctic. Similar to their close relative, the white whale, these mid-sized odontocetes liveremain in social group (pods) throughout their lives, often in association with sea ice. They are deep divers that feed on arcticArctic cod, polar cod,
All Arctic endemic marine mammals in the Barents Sea (polar bear, walrus, ringed seal, bearded seal, harp seal and hooded seal, white whale, narwhal and bowhead whale) are associated with sea ice throughout much or all of their annual cycle. Hence, they are all currently a conservation concern (e.g. Tynan and DeMaster, 1997; Stirling et al., 1999; Kovacs, 2004; Derocher, 2005; Belikov, 2008; Wiig et al., 2008; Kovacs and Lydersen, 2005, 2008; Kovacs et al. 2011a, 2012) because of the declines in Arctic ice coverage over recent decades, that have been particularly acute in the Barents Region (see Laidre et al., 2015).
Blue whales are also summer residents in the Barents Sea. They probably number 600-1,500 individuals in the North Atlantic. In recent years, this species has been sighted frequently in Svalbard waters, up the west coast at the shelf edge as well as north of Spitsbergen. Similar to the fin whale, it also enters deeply into Svalbard fjords. It is sighted from early summer until late fall, and appears to be extending is seasonal presence in the northern Barents Sea
The white whale/beluga whale is the most numerous of the three resident ice-associated Arctic whales in the Barents Sea. Similar to the other two high-arctic species, it can be found in high concentrations of drifting ice (>90% ice cover) in areas which are inaccessible to migratory species of whales. Satellite-tracking of white whales in Svalbard during summer and early autumn has shown a profoundly coastal distribution; tracking data from late autumn and early winter suggest that they remain close to these coastal areas, penetrating deep into extensive ice. During summer, they spend most of their time close to tidal glacier fronts in Svalbard or moving between them (Lydersen et al., 2001).