The scientific name for the Harp Seal has shifted frequently with generic names including Pagophoca, Pagophilis and Phoca, and specific names being either groenlandicus or groenlandica. Berta and Churchill (2011) returned to the name Pagophilus groenlandicus; this is the name currently recognized by the Society of Marine Mammalogy (SMM 2024).

Rice (1998) recognized two Harp Seal subspecies, P. g. groenlandicus and P. g. oceanicus, the former breeding in the western North Atlantic off North America and also around Jan Mayen in the Greenland Sea, and the latter breeding in the White Sea. But, there are mixed genetic findings and no consensus on the subspecies issue. Many studies have explored the relationships between animals from the three breeding groups. All studies have found distinctions, although the relative degrees of differentiation among the groups differ according to the methodology used (Yablokov and Sergeant 1963, Heptner et al. 1996, Meisfjord and Sundt 1996, Rice 1998, Perry et al. 2000, Carr et al. 2015). Animals from the Greenland Sea and the White Sea overlap extensively during summer foraging migrations (Folkov et al. 2004, Nordøy et al. 2008), but they return to their respective breeding grounds (Oien and Øritsland 1995). So it is the current convention to describe populations only according to their three distinct breeding areas: 1) off the east coast of Canada, both in the Gulf of St Lawrence and northeast of Newfoundland in an area known as “the Front”; 2) in the Greenland Sea, northwest of Jan Mayen Island, which traditionally has been called “the West Ice”; and 3) in the White Sea, which has traditionally been referred to as “the East Ice”.

European regional assessment: Near Threatened (NT)

Two of the three Harp Seal subpopulations occur within the European Marine Assessment area – the White Sea and the Greenland Sea subpopulations. Although the population sizes in these two regions are relatively large, both are small compared to historical numbers. The White Sea subpopulation is believed to have been c. six million animals in the late 1800s and now numbers some 1,500,000 (ICES 2019). There has been no survey of this Russian population since 2013. The Greenland Sea population was estimated to number 627, 410 animals in 2013 (Øigård et al. 2014), while the most recent estimate suggested a population size of 426, 808 (SD 52,120) (ICES 2019). The latest pup production survey in 2018 is similar to the one from 2012, with both being higher than the production estimated in 2015. With varying pup production numbers, in addition to uncertainty caused by methodological changes in the modelling regime to estimate population size, the trend of this population is currently classified as unknown; no new estimate emerged from modelling based on the latest pup production data (ICES 2023). However, it is known that Harp Seals in European waters are experiencing significant body condition declines, and experiencing increased juvenile mortality, which suggests that ecosystem changes in the Barents Region with global warming are making it more challenging for Harp Seals to find enough food (Øigård et al. 2013, Stenson et al. 2020). It is believed that the large standing stock of cod is one of the issues; cod compete with seals for forage fish (ICES 2023). This, in addition to the fact that sea ice has declined 2.5x times more rapidly in the Barents Sea Region compared to the Arctic as a whole, creates a significant risk for Harp Seals. Hunting is ongoing, though at reduced levels compared to the past. Ongoing reductions in breeding habitat are a serious threat to the two European Harp Seal populations (Kovacs et al. 2011, 2012, 2021). Harp Seals in European waters are likely to decline in the near-term future given the ongoing habitat losses, coupled with ecosystems changes, due to global warming. Breeding and resting habitats have declined markedly (over 30%) for Harp Seals in the Northeast Atlantic, and they are expected to continue to decline.

Based on the ongoing declines in breeding habitat and documented declines in body condition, the European population of Harp Seals is assessed as Near Threatened under criteria A3c. It is suspected that near-term future population decline may be close to, or exceed the threshold for Vulnerable under A3 (30%), so reassessment of this species should be scheduled within the decade.

Harp Seals are widespread in the North Atlantic and the adjacent Arctic seas. Their range extends from Hudson Bay and the Foxe Basin, Baffin Island, and the Davis Strait in the west, south to the Gulf of Saint Lawrence and Newfoundland in the western North Atlantic, east to northern Norway, the White Sea and Kara Sea and northward through the Greenland and Barents seas in the Northeast Atlantic region. The northern limit is at least to Franz Joseph Land (Russia) and Svalbard (Norway) and may extend to 85 degrees north depending on ice conditions (Lavigne and Kovacs 1988, Rice 1998, Lavigne 2018).

Harp Seals often wander southward outside this range and vagrants have reached the United Kingdom, the Faroe Islands, Denmark, Germany, France, and Spain (Heptner 1976, Ronald and Healy 1981, Van Bree 1997, Bloch et al. 2000).

All three Harp Seal populations have been assessed recently (although new surveys are not available for the White Sea). Recent pup production surveys have been carried out in the Greenland Sea in 2012, 2018 and 2022. A total of 54,181 (95% CI: 36,078–72,284) pups were estimated to have been born in 2018 and 92,769 (CV 20.2) in 2022, returning to a level similar to the 2012 survey (89,590, CV 0 13.7%; ICES 2023). These estimates are significantly lower than estimates obtained in similar surveys in 2002 and 2007. The estimated population size according to the 2018 survey was 426,800 (95% CI 313,000 – 540,600; ICES 2019). Model fitting issues and uncertainty about the available reproductive data did not allow for a new estimate to be created with the most recent data, so the current trend for this population is unknown (ICES 2023). The White Sea/Barents Sea Harp Seal population has not been surveyed since 2013. However, abundance-based upon the existing time series of pup production estimates, fecundity and removals suggest a population size of 1,497,000 (95% CI 1,293,000–1,701,000), which suggests a stable trend (ICES 2019, 2023).

The Northwest Atlantic population was assessed in 2023 based on pup production surveys carried out in 2017 (ICES 2023). Pup production was estimated to be 746,500 (95% CI 572,000 - 922,500), which is the lowest since 1994, although not significantly different from the previous survey in 2012 (Stenson et al. 2020). The total Northwest Atlantic population was estimated to be 7.6 million (95% CI 6.6 – 8.8 million) in 2019 (Hammill et al. 2021) and the trend is either stable or increasing slightly (ICES 2023).

A small whelping patch was found near South Greenland in 2007 (Rosing-Asvid 2008), but the source of these animals and the inter-annual stability of this group is not known. However, this finding is particularly interesting in light of climate change.

Harp Seals are medium-sized true seals. Adult males and females are similar in size, about 1.8 m long and weigh about 130 kg (Lavigne and Kovacs 1988). Females reach sexual maturity between four and eight years of age (e.g., Frie et al. 2003); this has varied considerably over the last century, largely as a consequence of population size that has been determined by harvest levels. Males reach physiological maturity around the same time as females but probably do not participate in breeding until they are somewhat older.

Birthing takes place within drift-ice areas from late February to April in the respective breeding areas. There is some variation across the species’ range in the precise timing, but herds are highly synchronised (Lavigne and Kovacs 1988). Pups are born weighing about 10 kg and are nursed for 12 days, during which time they gain weight at about 2.2 kg per day (Kovacs and Lavigne 1985, Kovacs 1987, Kovacs et al. 1991, Lydersen and Kovacs 1996). Pups are referred to as “whitecoats” because they are born with an insulating coat of white lanugo. They are quite sedentary in the first weeks of life and few swim before they are weaned. Lactating females spend up to 85% of their time in the water, depending on the weather (Lydersen and Kovacs 1993). Mothers locate their pups in the drifting ice based on physical cues in the environment, with final identification of their pup by smell (Kovacs 1995). Towards the end of lactation, females come into oestrus and mate (Lavigne and Kovacs 1988). Weaned pups remain on the ice for up to six weeks, losing up to 50% of their body mass before entering the water and commencing to capture prey. During the post-weaning fast they complete the moulting of the lanugo. After this coat is shed, the short, stiff, black and silver-grey pelage is exposed, and the juveniles are known as “beaters” until they are about a year old. Pups disperse from the breeding patches when the ice melts, and do not return until they are breeding age. Beaters transition into the bedlamer pelt which is heavily spotted, which they have until close to sexual maturity when the face becomes black and the harp starts to form and the spots are gradually lost. Harp Seals mate toward the end of lactation. It is thought to be a promiscuous mating system, but little is in fact known about the breeding system (Lavigne and Kovacs 1988). Gestation lasts about 11.5 months, including a three-to-four-month period of delayed implantation (Stewart et al. 1989). The maximum life span of a Harp Seal is approximately 30 years; most animals that reach sexual maturity live past 20 years. Both males and females are sexually active until the end of their lives, showing no signs of reproductive senescence (Ronald and Healey 1981).

Harp Seals undergo an annual post-breeding moult, from early April to early May (Lavigne and Kovacs 1988), forming large aggregations north of the various breeding areas. Harp Seals are highly migratory, and after breeding Northwest Atlantic seals follow the pack ice up the coast of Labrador, with small numbers going into Hudson Bay and around Baffin Island, and the rest travelling up both sides of Davis Strait. The Jan Mayen and White Sea groups migrate northward and mix in the northern Barents Sea (Folkow et al. 2004). All populations begin their return migration to their respective breeding areas in the late autumn/early winter. Harp Seals pups and juveniles feed a lot on invertebrate prey, especially euphausiids (Thyanoessa spp.) and pelagic amphipods (Parathemisto spp.) (Nilssen et al. 2001). Adults in Greenlandic waters eat pelagic crustaceans, and fish such as Capelin (Mallotus villosus), Sandeel (Ammodytes sp.), Polar Cod (Boreogadus saida) and Arctic Cod (Arctogadus glacialis). Commercial species such as Atlantic Cod (Gadus morhua) appear to be of minor importance in the diet (Kapel 2000), largely because Harp Seals of all ages eat relatively small prey and tend to specialize somewhat on polar species (Lindstrom et al. 2013). In the Barents Sea, Harp Seals eat Amphipods, Shrimps and small fish including Polar Cod, Sculpin (Cottidae), Snailfish (Liparidae) and Capelin (Nilssen et al. 1995, Wathne et al. 2000, Lindstrom et al. 2013, Enoksen et al. 2016). The Seals of Newfoundland eat Capelin and Arctic Cod, and off Labrador, they eat Arctic Cod and Atlantic Herring (Clupea harengus). In the Gulf of St Lawrence, Harp Seals consume Capelin, Herring, small Atlantic Cod, Arctic Cod and Redfish (Sebastes spp.) (Lawson et al. 1995). Harp Seals feed heavily in winter and summer and less in spring and autumn. They are relatively shallow divers. Animals satellite-tagged at Jan Mayen stayed close to the edge of the pack ice during the spring moult, usually diving to less than 100 m, but by July tagged Seals in the Barents Sea dove to 400 m. Overall, the deepest dives occurred during the day in winter (Folkow et al. 2004).

Harp seals in the European populations have distributional hot spots north of Svalbard and along the East Greenland shelf (Hamilton et al. 2021).

Natural predators of Harp Seals include Polar Bears, Killer Whales and Greenland Sharks (Lavigne and Kovacs 1988). In Svalbard, 13% of Polar Bear prey is comprised of Harp Seals (Derocher et al. 2002).

Harp Seals have been harvested for thousands of years by native peoples of the North Atlantic, including coastal Northern Europeans historically when the species occurred in the Baltic (Stora and Ericson 2004). Basque whalers began taking Harp Seals in more northerly waters in the 1500s. By the mid-1600s, French settlers began the hunt in the Gulf of St Lawrence, developing land-based netting techniques on the St Lawrence River in the 1700s. By the 1800s, schooner-based sealing developed, and the number of seals harvested rose dramatically in the Northwest Atlantic; from 1803-1816 the average annual was 117,000 specimens. The peak of sealing in the Northwest Atlantic occurred between 1818 and 1862, when 500,000 seals per year were harvested in many years, reaching maximum peeks of 640,000-740,000 in single years. During that time, it is estimated that 18.3 million harp seals, mostly whitecoats, were killed for oil. There was also early commercial harvesting in the Northeast Atlantic, though at somewhat lower levels. At Jan Mayen, the catch began falling in the late 1850s, likely due to overharvesting and population depression. From 1860 to 1900, an estimated 12.8 million seals were harvested from the West Ice (Lavigne and Kovacs 1988).

The 20th century saw the advent of steel-hulled ships, and the hunt continued, though Harp Seals became more valued for their pelts than their oil. The size of all three Harp Seal populations has fluctuated through time, driven largely by the size of the commercial harvests (Sergeant 1976). In 1983, the European Economic Community imposed an import ban on seal products, because of public reactions to the white-coat harvest and the average annual commercial harvests fell precipitously. Indigenous groups lobbied the EU parliament successfully and in 2009 exemptions were made for subsistence harvest products. Greenlandic subsistence catches of Harp Seals vastly outnumber commercial harvests in recent decades. Greenland took 50,000-100,00 Harp Seals annually in the 1990s and 2000s (https://nammco.no/catch-database). Harvests in the last decade average some 40,000. Norwegian catches for the West Ice are generally under 10,000 animals per year and little hunting occurs in the White Sea.

Capelin collapses in the Barents Region in the 1980s resulted in Harp Seals shifting their distribution southward and foraging along the coast of Norway, resulting in several major mortality events in shore-based net fisheries. Bycatch mortality from nets was estimated to be 56,647 (perhaps up to 100,000) in 1987, and 21,474 in 1988 though it is thought that actually mortalities might have exceeded 100,000 in each of these years (Haug et al. 1991). These events demonstrated the potential risk that fisheries represent to Harp Seals. A major assessment of fisheries catches vs marine mammal consumption suggests that there is strong potential for direct competition between fisheries and pinnipeds (and other marine mammals) in the Greenland Sea, while competition in the Barents Sea is likely not currently an issue (Skern-Mauritzen et al. 2022).

A major threat to Harp Seals is climate warming (Laidre et al. 2008, 2015, Kovacs et al. 2011, 2012, 2021) which is already impacting all populations through reductions in their drift ice breeding habitats and likely via indirect impacts on their prey populations as well. Recently there have been years with very high pup mortalities because of low ice availability and great variability and generally low survivorship seem to be the new norm (Johnston et al. 2005, Bajzak et al. 2011, Stenson and Hammill 2014, Hammill et al. 2015, 2021, Stenson et al. 2020). In North America, years with high stranding numbers are correlated with environmental conditions, including warm temperatures and little sea ice (Haverkamp et al. 2023). Shifts have occurred in the location of whelping locations in the Greenland Sea and in the Northwest Atlantic during years when ice conditions have been extremely poor (Rosing-Asvid 2008, Stenson et al. 2016, 2020). When pupping occurs outside the traditional areas, the young may be exposed to ice that is less stable and to different prey fields during the period when they are first learning to find food. In the Greenland Sea and in areas off Newfoundland, increased predation from Polar Bears which travel great distances to seek out the pupping concentrations (Peacock et al. 2013) might become a significant survivorship issue. Other changes include shifts in abundance and distribution of many key prey species for Harp Seals which has negatively impacted body condition and reproductive rates in all populations (Øigård et al. 2013, Stenson et al. 2020). Large Atlantic cod stocks in the Northeast Atlantic are likely competing with Harp Seals for prey (Bogstad et al. 2015, Stenson et al. 2020) and the overall borealisation and base-line nutrient shifts in the Barents Sea is likely to continue to negatively impact Harp Seal’s traditional Arctic fish and invertebrate prey populations (Fossheim et al. 2015, de la Vega et al. 2022).

Harp Seals are hunted for meat, leather and fur. Some attempts have also been made to utilise oil in the nutraceutical trade.

In the Northeast Atlantic, quotas for Harp Seals are set by the Joint Norwegian/Russian Commission, based on recommendations made by the International Council for Exploration of the Sea (see ICES 2019, 2023). White-coated pups are protected in Norway and Russia. However, there are no quotas in Greenland.

Further research into the population trend of this species is recommended.