Bearded Seals are the largest northern phocid seal (Kovacs 2018). Adults are on average 2.3 m (standard) in length and weigh an average of 275 kg. Females are slightly longer and (seasonally) substantially heavier than males (Burns 1981, Andersen et al. 1999). In spring females can weigh in excess of 400 kg (Kovacs and Lydersen 2006, Cameron et al. 2010). Bearded Seals naturally occur at quite low densities, and they are typically solitary, although they do form small, loose aggregations at times, particularly if sea ice is limited during the spring (Bengtson et al. 2005, Kovacs 2018). Bearded Seals are strongly associated with sea ice and are principally benthic feeders; these two attributes explain their general distribution patterns in shallow coastal shelf seas (Citta et al. 2018, Hamilton et al. 2021, 2022). However, bearded seals do occupy offshore, deep water (3,000 m +) habitats in areas with high concentrations of drift-ice in the Arctic Ocean north of the Barents Sea (Llobet et al. 2023, KMK pers. obs.)

In Svalbard, females reach sexual maturity at an age of five, while males are six years of age when they are sexually mature though they are likely some years older before they compete successfully to breed (Andersen et al. 1999). In Alaskan waters, sexual maturity is reached between 2.5–4 years in females (Quakenbush et al. 2011, Alaska Department of Fish and Game 2020) and males reach sexual maturity somewhat older, at 6–7 years (Burns 1981). Final body size in Bearded Seals is reached at approximately 9–10 years (McLaren 1958) with maximum longevity being 25–30 years (Cameron et al. 2010). Pups are born at an average length of 131 cm and an average weight of 37 kg (Burns 1981, Kovacs et al. 2020). Sex ratios are 1:1 at birth but are skewed toward females at older ages, perhaps due to higher mortality in males though this may be a hunt bias because struck and lost is lower in females because they are fatter and float when shot (Johnson et al. 1966, Quakenbush et al. 2011).

Bearded Seal pups are born in drift ice areas or on small floes of annual ice that fracture away from shore-fast ice as it breaks up in late spring (Kovacs et al. 1996, Kovacs and Lydersen 2006). They also have been documented to use glacier ice pieces floating on the sea for birthing and nursing when forced to by the lack of availability of first-year sea ice (Lydersen et al. 2014, Kovacs et al. 2020). The large precocial pups swim within hours of birth (Lydersen et al. 1994, 1996). Peak birthing occurs between late March and mid-May, varying somewhat across the Bearded Seal’s range (Burns 1981, Kovacs 2018). Gjertz et al. (2000) estimated that pups in Svalbard are weaned when 18–24 days of age. Nursing might be somewhat shorter for the Pacific subspecies; Burns (1981) suggested that pups are weaned at 12–18 days of age (though longitudinal records for individuals are lacking for the Pacific subspecies). Prior to weaning, their aquatic skills develop to the degree that they spend about half their time in the water, diving for up to 5.5 minutes to depths of up to 84 m (Lydersen et al. 1994). Mothers spend over 80% of their time in the water while caring for a dependent pup (Lydersen and Kovacs 1999); about half that time is spent away from the neonate, presumably conducting foraging dives. Females haul-out to nurse their pups, on average three times a day. The small amounts of time mothers spend out of the water when pups are young is thought to be an adaptive response to Polar Bear (Ursus maritimus) predation; when only the pup is on the surface, it is less conspicuous to hunting bears (Krafft et al. 2000). Diving depths during the nursing period generally reflect local bathymetry (Gjertz et al. 2000, Krafft et al. 2000). Mating takes place toward the end of lactation, similar to other phocid seals.

Following the spring nursing and mating periods, weaned pups disperse along coastlines in Svalbard, sometimes going offshore into ice-filled waters for periods of some days before returning to waters over the coastal shelf, and then settling into areas where they remain resident at least the rest of the first year of life (Hamilton et al. 2019a), and likely beyond this time. Diving skill develops over the first weeks of life, stabilizing to adult-like abilities by the time pups are about 50 days old, when pups spent 75% of their time diving and less than 10% of their time hauled out. However, pups lack the highly specialized behaviour patterns displayed by adults in terms of movement patterns. Similar short range coastal dispersion of pups has been documented in Alaska (Citta et al. 2018). Juvenile Bearded seals tracked in the Bering, Chukchi and Beaufort Seas occupied shallow coastal waters with intermediate concentrations and showed strong affiliation with sea ice edges (Breed et al. 2018, Cameron et al. 2018, Olnes et al. 2020). The strong affiliation with edges seems to have disappeared in a more recent study following reduction in overall sea ice availability in the Pacific Arctic and might have been an artifact of where intermediate ice concentrations were found in the past (Olnes et al. 2021).

Bearded Seal males produce elaborate downward trilling vocalizations during the spring to display to females during their mating period. These “songs” dominate the Arctic soundscape in spring across the species range (e.g. Cleator et al. 1989, Ahonen et al. 2017, Heimrich et al. 2020, Moore et al. 2012, Llobet et al. 2023). Propagation models suggest that Bearded Seal vocalizations can travel up to 40 km, depending on ambient noise levels (Crance et al. 2022). Individual males use distinct songs and occupy the same territories over a series of consecutive years within constraints imposed by variable ice conditions, or they show a roaming strategy (Van Parijs et al. 2001, 2003, 2004). Males also exhibit aggressive behaviour to each other during breeding, including bubble-blowing and physical combat, so the mating system is presumably polygynous to some degree. Bearded Seals from different regions exhibit strong dialect differences in their songs and acoustic repertoires (Risch et al. 2007, Charrier et al. 2013) and males recognise songs from their region and respond differently to them compared to sounds from other regions (Charrier et al. 2013). Calling rates are linked to sea ice concentrations and earlier seasonal losses of sea ice cover in the Pacific region has been linked to earlier termination of spring calling (MacIntyre et al. 2015, Llobet et al. 2023). Bearded Seals have acute underwater hearing and an exceptionally broad frequency range, and they can extract species-specific signals from background noise well (Sills et al. 2020a). Loud noise exposure tests showed that Bearded Seals experience temporary threshold shifts when exposed to noise levels analogous to seismic air gun sounds (Sills et al. 2020b).
In some Arctic regions Bearded Seals are reported to be very sedentary throughout the year, occupying relatively small coastal home ranges (e.g. Hamilton et al. 2018, 2021, Rosing-Asvid et al. 2012, 2015). In Svalbard pups settle into small home ranges after a dispersal phase following weaning; maximum straight-line displacement from the natal fjord was 150 km, and no tracked individuals left the archipelago (Hamilton et al. 2019a). However, In the Beaufort-Bering-Chukchi region as well as in Baffin Bay/Davis Strait between west Greenland and Canada Bearded Seals undergo seasonal movements linked with the advance and retreat of sea ice in the (Burns 1981, Frost et al. 2008, Cameron et al. 2010, Breed et al. 2018, Boye et al. 2020), although some individuals do remain in the northern reaches of their range throughout the year in both areas (Frouin-Mouy et al. 2017, Jimbo et al. 2019).

Dive and movement behaviour suggest that Bearded Seals behave as a generalist species, with a lot of individual variation in foraging and movement patterns (Hamilton et al. 2018, Olnes et al. 2020) although adult animals in Svalbard appear to be highly specialized feeders at the level of the individual, remaining in small ranges and following set paths between resting and foraging areas over sequential seasons (Hamilton et al. 2018, 2019b). Additionally, Bearded Seals were found to have the smallest feeding niche-space among 10 marine mammal species studied in the Barents Region. This niche was described as benthic-benthopelagic and did not overlap with the other species (MacKenzie et al. 2022). Similar findings of a unique feeding niche are reported for Bearded Seals in the White Sea (Svetocheva and Svetochev 2015). Bearded Seals feed primarily on or near the bottom, although they do also take some pelagic prey, and most diving is to depths of less than 200 m though dive depths for both young-of-the-year and adults have been recorded down to 500 m (Gjertz et al. 2000, Rosing-Asvid et al. 2012, Hamilton et al. 2018). Bearded Seals use their elaborate, flexible whiskers to search for food items on and in soft bottom substrates and they have powerful suction abilities afforded by a unique bifurcated tongue and skull morphology that promotes suction abilities (Marshall et al. 2006, 2008, Summarell et al. 2015, Kienle and Berta 2016).

The diet of Bearded Seals varies by age, location, and season (see Lowry et al. 1980). Polar Cod (Boreogadis saida), Sculpins, Spider Crab, and Shrimps (Sabinea sptemcarinatus and Sclerocrangon boreas) are the most frequent prey items in Svalbard (Hjelset et al. 1999). However, various Cod species and other demersal fish, and worms are also regular components of the diet. A wide variety of prey has been reported from the Pacific Arctic. Quakenbush et al. (2011) analyzed the frequency of occurrence of prey in 943 Bearded Seal stomachs collected from the Bering and Chukchi Seas during 1960–2009 and identified 213 different prey taxa. The most commonly eaten groups were Crabs, Shrimps, Clams, Snails, benthic and demersal fishes, and echiuroid worms. These authors found a significant increase in consumption of gadid fishes, principally Polar Cod (also known as Arctic cod in North America) and Saffron Cod (Eleginus gracilis), from the 1960s to the 2000s.

Bearded Seals have an extended moulting period and animals can be found shedding hair from April to August, though there appears to be a peak in May/June for both subspecies (Burns 1981, Gjertz et al. 2000, Thometz et al. 2021). During the moult they spend much of their time hauled out and are reluctant to enter the water (Kovacs and Lydersen 2006). Bearded Seals use sea ice as a haulout platform on a year-round basis whenever it is available, preferring small and medium-sized floes and generally avoiding large floes (Simpkins et al. 2003). However, they will haul out on land in the summer in the absence of sea ice (e.g., Merkel et al. 2013, Olnes et al. 2020) and are known to use inland water bodies at least seasonally (Stewart and Lockhart 2005, Gryba et al. 2021). They are rarely found more than a body length from access to water, even if hauled out on land (Kovacs 2018).

Natural predators of Bearded Seals include Polar Bears, Killer Whales (Orcinus orca), sleeper sharks (Somniosus spp.), and Walruses (Odobenus rosmarus) (Lowry and Fay 1984, Lowry et al. 1987, Kovacs and Lydersen 2006, Leclerc et al. 2012, Kovacs 2018). Killer whales are increasing in several Arctic locales, which is likely to influence predation rates on other marine mammals, including Bearded Seals (Ferguson et al. 2010, Stafford et al. 2019)

The species has a patchy distribution throughout much of the Arctic and sub-Arctic and is found in West Greenland, Canada (Eastern Canadian Archipelago–Hudson Bay, south to Labrador), and in the Pacific Arctic throughout the shallow Beaufort-Bering-Chukchi region (including Alaskan coastal areas), as well as in the Sea of Okhotsk, extending westward across the coast of the Siberian seas, through the Laptev, Kara, and White sea as well as the coasts of Novaya Zemlya (in Russia) and westward across the Barents Region to South and East Greenland including the Svalbard and Frans Josef Land archipelagos (Kovacs 2018). Bearded seals also occur offshore in some deep-water areas (>2,000 m) in the Barents Region that have high concentrations of drift ice (Llobet et al. 2023, KMK pers. obs.).

Bearded Seals have been reported as vagrants in the Gulf of Saint Lawrence, northern Newfoundland, and in Massachusetts in the Northwest Atlantic (Gosselin and Boily 1994), as well as in Japan and China in the North Pacific (Naito 1979, Rice 1998). They are occasionally reported from the north coast of Iceland (Hauksson and Boganson 1995) and many vagrants have been reported within Europe, as far south as Portugal (van Bree 2000).

Norway listed Bearded Seals on the national Red List in 2021 as Near Threatened because of the threats posed to the species through habitat deterioration due to global warming (Eldegard et al. 2021). However, licensed hunters can shoot Bearded Seals in Svalbard, outside protected areas and during open seasons, that are set in periods when Bearded Seals shot in the water are least likely to sink (Kovacs and Lydersen 2006). Bearded Seals are able to use glacier ice pieces that have calved into the sea as haul-out platforms, so tidal glacier fronts are increasingly important to them in areas where sea ice declines are marked and where tide-water glaciers are common (Lydersen et al. 2014). Such glacier fjords occur mainly in East Greenland, Svalbard and Frans Josef Land. These areas might represent important breeding refugia for some time to come, so should be considered for special conservation status.

Boertmann and Bay (2018) evaluated Bearded Seals as being Least Concern in Greenland. Throughout Russia the Fisheries and Preservation of Aquatic Resources Law (Federal Law No. 338-FZ) provides for subsistence harvest of seals by aboriginal Russian peoples, including Bearded Seals. The Committee on the Status of Endangered Wildlife in Canada assessed this species in Canada as being a high priority conservation concern in need of assessment for extinction risk (COSEWIC 2024). In the USA Bearded Seals are listed as threatened under the Endangered Species Act (Federal Registry 2012 - ESA 77 FR 76740) because of the threats from climate change (Cameron et al. 2010). This has resulted in a Designation of Critical Habitat for the Beringia Bearded Seal Population (Federal Register 2022). The Marine Mammal Protection Act of 1973 prohibits the taking of Bearded Seals except for Alaska Native subsistence hunts or for production of handicrafts. In Norway the Bearded seal is classified as Near Threatened because of the risks of climate change (artsdatabanken.no/rodlisteforarter/2021/835).

The species is included on Annex V (animal and plant species of community interest whose taking in the wild and exploitation may be subject to management measures) of the EU Habitats Directive, and on Appendix III (protected fauna species) of the Bern Convention (Convention on the Conservation of European Wildlife and Natural Habitats).

Both the research community and Arctic indigenous knowledge holders have called for changing ice concentrations to be considered in the management and conservation of Bearded Seals (Gryba et al. 2021, Kovacs et al. 2021).