{{Short description|Species of pinniped}} {{other uses|Grey Seal (disambiguation)}} {{good article}} {{Use dmy dates|date=January 2025}} {{Use British English|date=December 2015}} {{speciesbox | image = Focas grises (Halichoerus grypus), playa de Horsey, Norfolk, Inglaterra, 2022-11-20, DD 11.jpg | image_alt = Grey seal with dark spots touches its nose to a white seal pup. | image_caption = Female with pup on Horsey Beach, England | image2 = Donna Nook NNR - Grey Seal pupping and breeding season - 38804871202 (cropped).jpg | image2_alt = Large dark brown seal with long, sloped snout. | image2_caption = Male in Donna Nook, England | status = LC | status_system = IUCN3.1 | status_ref = <ref name=IUCN>{{cite iucn |author=Bowen, D. |date=2016 |title=''Halichoerus grypus'' |volume=2016 |article-number=e.T9660A45226042 |doi=10.2305/IUCN.UK.2016-1.RLTS.T9660A45226042.en |access-date=19 November 2021}}</ref> | display_parents = 3 | genus = Halichoerus | parent_authority = Nilsson, 1820 | species = grypus | authority = (O. Fabricius, 1791) | range_map = Grey_Seal_Halichoerus_grypus_distribution_map.png | range_map_caption = Grey seal range<ref name=IUCN/> }}
The '''grey seal''' ('''''Halichoerus grypus'''''), or '''gray seal''' in the United States, is a large seal of the family Phocidae, which are commonly referred to as "true seals" or "earless seals". The only species classified in the genus '''''Halichoerus''''', it is found on both shores of the North Atlantic Ocean. In Latin, ''Halichoerus grypus'' means "hook-nosed sea pig".<ref name="marine mammals">{{cite book |last1=Hall |first1=Ailsa J. |last2=Russell |first2=Debbie J.F. |title=Gray Seal: Halichoerus grypus, Encyclopedia of Marine Mammals |date=2018 |publisher=Academic Press |isbn=9780128043271 |pages=420-422 |edition=Third |url=https://doi.org/10.1016/B978-0-12-804327-1.00139-4}}</ref> It is also known as the '''horsehead seal''', owing to its large head.<ref name="NOAA 2019">{{cite web | title=Gray Seal | website=NOAA | date=2019-07-08 | url=https://www.fisheries.noaa.gov/species/gray-seal | access-date=2021-01-05}}</ref>
The grey seal is large and heavy, with individuals from the eastern Atlantic being {{cvt|1.6|–|2.3|m}} long and weighing {{cvt|100|–|310|kg}}, while individuals from the western Atlantic are up to {{cvt|2.7|m}} long, and can reach a weight of as much as {{cvt|400|kg}}. It is found widely across the northern Atlantic, ranging from the US to Russia, and occasionally as far south as Portugal. It can be divided into two subspecies: the Baltic grey seal (''Halichoerus grypus grypus''), found in the Baltic Sea, and the Atlantic grey seal (''Halichoerus grypus atlantica''), found everywhere else. The largest populations are in Canada and the UK.
Grey seals have a varied diet, feeding mostly on fish, and occasionally on invertebrates such as octopuses and lobsters. Their main predators are orcas, and they are also prey to sharks. The pups are preyed upon by eagles and gulls.
==Taxonomy== There are two recognized subspecies:<ref name=msw3>{{MSW3 Wozencraft | pages = | id = 14001036}}</ref> {| class="wikitable " |- ! Image !! Subspecies !! Distribution |- |120px|alt=see caption.|| ''Halichoerus grypus grypus'' {{small|Fabricius, 1791}} || Baltic Sea |- |120px|alt=see caption.|| ''Halichoerus grypus atlantica'' {{small|Nehring, 1886}}|| western North Atlantic stock (eastern Canada and the northeastern United States), the eastern North Atlantic stock (British Isles, Iceland, Norway, Denmark, the Faroe Islands, and Russia)<ref name="NOAA 2019"/> |- |}
The type specimen of ''H. g. grypus'' (Zoological Museum of Copenhagen specimen ZMUC M11-1525, caught in 1788 off the island of Amager, Danish part of the Baltic Sea) was believed lost for many years, but was rediscovered in 2016, and a DNA test showed it belonged to a Baltic Sea specimen rather than from Greenland, as had previously been assumed (because it was first described in Otto Fabricius' book on the animals in Greenland: ''Fauna Groenlandica''). The name ''H. g. grypus'' was therefore transferred to the Baltic subspecies (replacing ''H. g. macrorhynchus''), and the name ''H. g. atlantica'' resurrected for the Atlantic subspecies.<ref>{{cite journal|last1=Olsen|first1=Morten Tange|last2=Galatius|first2=Anders|last3=Biard|first3=Vincent|last4=Gregersen|first4=Kristian|last5=Kinze|first5=Carl Christian|title=The forgotten type specimen of the grey seal [''Halichoerus grypus'' (Fabricius, 1791)] from the island of Amager, Denmark|journal=Zoological Journal of the Linnean Society|volume=178|issue=3|pages=713–720|date=April 2016|doi=10.1111/zoj.12426|doi-access=free}}</ref>
Molecular studies have indicated that the eastern and western Atlantic populations have been genetically distinct for at least one million years, and could potentially be considered separate subspecies.<ref name=Boskovic1996>{{cite journal | author = Boskovic, R.| year = 1996 | title = Geographic distribution of mitochondrial DNA haplotypes in grey seals (''Halichoerus grypus'') | journal = Canadian Journal of Zoology | volume = 74 | issue = 10 | pages = 1787–1796 | doi = 10.1139/z96-199| bibcode = 1996CaJZ...74.1787B |display-authors=etal}}</ref>
In 2022, overlap in the range of the two subspecies was recorded for the first time. This brings the possibility that hybridisation may occur. As of 2026, no hybrids have been reported.<ref>{{cite journal |last1=Galatius |first1=Anders |last2=Olsen |first2=Morten Tange |last3=Allentoft-Larsen |first3=Marc |last4=Balle |first4=Jeppe Dalgaard |last5=Kyhn |first5=Line Anker |last6=Sveegaard |first6=Signe |last7=Teilmann |first7=Jonas |title=Evidence of distribution overlap between Atlantic and Baltic grey seals |journal=Journal of the Marine Biological Association of the United Kingdom |date=15 March 2024 |volume=104 |doi=10.1017/S0025315424000213 |url=https://www.cambridge.org/core/journals/journal-of-the-marine-biological-association-of-the-united-kingdom/article/evidence-of-distribution-overlap-between-atlantic-and-baltic-grey-seals/764FA3AF71B4FBED51EBE9D0028C8316 |publisher=Cambridge University Press}}</ref>
==Description== [[File:Grey seals (Halichoerus grypus) - geograph.org.uk - 1016293.jpg|thumb|left|alt=Smaller cream-coloured seal, left, and larger, dark brown, wrinkled seal, right.|Female (left) and male (right), displaying difference in colour and snout shape, Horsey Beach, England]] thumb|alt=Small, solid grey-coloured seal.|A yearling of ambiguous sex — juveniles are often a solid colour, and can be difficult or impossible to sex The grey seal is large and heavy: In the eastern Atlantic, males are typically {{cvt|1.95|–|2.3|m|ftin|0|abbr=on}} long and weigh {{cvt|170|-|310|kg|lb|abbr=on}}; the females are much smaller, typically {{cvt|1.6|–|1.95|m|ftin|0|abbr=on}} long and {{cvt|100|–|190|kg|lb|abbr=on}} in weight. Individuals from the western Atlantic are often much larger, with males averaging up to {{cvt|2.7|m|ftin|0|abbr=on}} and reaching a weight of as much as {{cvt|400|kg|lb|abbr=on}} and females averaging up to {{cvt|2.05|m|ftin|0|abbr=on}} and sometimes weighing up to {{cvt|250|kg|lb|abbr=on}}. Record-sized bull grey seals can reach about {{cvt|3.3|m|ftin|0|abbr=on}} in length.<ref name= FAO>{{cite book |last=Working Party on Marine Mammals |date=1978 |title=Mammals in the Seas, Volume 4 |url=https://books.google.com/books?id=j-Je25qovO8C&q=Halichoerus |location=Rome |publisher=Food & Agriculture Org. |page=257 |isbn=92-5-100514-1}}</ref><ref>{{cite book |last1=Naughton |first1=D. |year=2014 |title=The Natural History of Canadian Mammals: Opossums and Carnivores |publisher=University of Toronto Press |url=https://utorontopress.com/9781442622319/the-natural-history-of-canadian-mammals/}}</ref><ref>{{cite book |last1=Bjärvall |first1=A. |last2=Ullström |first2=S. |year=1986 |title=The mammals of Britain and Europe |location=London |publisher=Croom Helm |isbn=0-7099-3268-5}}</ref> A common average weight in Great Britain was found to be about {{cvt|233|kg|lb|abbr=on}} for males and {{cvt|154.6|kg|lb|abbr=on}} for females whereas in Nova Scotia, Canada, adult males averaged {{cvt|294.6|kg|lb|abbr=on}} and adult females averaged {{cvt|224.5|kg|lb|abbr=on}}.<ref name= FAO/><ref>{{cite journal |last1=Lidgard |first1=D. C. |last2=Boness |first2=D. J. |last3=Bowen |first3=W. D. |year=2001 |url=https://repository.si.edu/handle/10088/343 |title=A novel mobile approach to investigating mating tactics in male grey seals (''Halichoerus grypus'') |journal=Journal of Zoology |volume=255 |issue=3 |pages=313–320|doi=10.1017/S0952836901001418 |hdl=10088/343 |url-access=subscription }}</ref><ref>{{cite journal | url=https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.1995.tb02730.x | doi=10.1111/j.1469-7998.1995.tb02730.x | title=Mass transfer during lactation of an ice-breeding pinniped, the grey seal (''Halichoerus grypus''), in Nova Scotia, Canada | year=1995 | last1=Baker | first1=S. R. | last2=Barrette | first2=C. | last3=Hammill | first3=M. O. | journal=Journal of Zoology | volume=236 | issue=4 | pages=531–542 | url-access=subscription }}</ref>
Colours and patterns are highly variable. Males tend to have a light pattern on a dark background, while females tend to have the opposite — a dark pattern on a light background, often with a noticeably light belly. The neck and chest of males tend to be wrinkled and scarred, while females are smoother. Males have an especially wide muzzle. Males have a large, visible opening on the lower abdomen, while females have no obvious openings. Juveniles are often a solid colour, and can be difficult or impossible to sex.<ref name="marine mammals"/> About 1 in 400 seal pups are melanistic, where they have a solid black coat.<ref>{{cite web |last1=Dilger |first1=Mike |title=Where and when to see grey seal pups in the UK |url=https://www.discoverwildlife.com/holidays-days-out/uk/wildlife-spectacles-grey-seal-pups |website=BBC Discover Wildlife |access-date=12 April 2026 |date=8 October 2021}}</ref>
===Differences from other seals=== [[File:Harbour Seal (Phoca vitulina) and Atlantic Grey Seal (Halichoerus grypus) on Scarfi Skerries - geograph.org.uk - 7998293.jpg|thumb|alt=Cream-coloured harbour seal with a short snout, left, and grey-coloured grey seal with a long snout, right.|A harbour (or "common") seal (left), and a grey seal (right). Note the difference in snout length]] Grey seals lack external ear flaps (as with their fellow earless seals), and characteristically have large snouts, often referred to as a "Roman nose".<ref>{{Cite book|title = Marine Science: The Dynamic Ocean|author = Schuster, Marreno|author2 = Glen, Megan|publisher = Pearson|year = 2011|isbn = 978-0-13-317063-4|location = US Satellite Laboratory|page = 107}}</ref><ref name=discover>{{cite web |title=How to tell the difference between grey and common seals |url=https://www.discoverwildlife.com/how-to/identify-wildlife/how-to-identify-british-seals |website=Discover Wildlife |access-date=26 March 2026}}</ref>
The Harbour seal occurs across the entire range of the grey seal,<ref>{{cite iucn |author=Lowry, L. |date=2016 |title=''Phoca vitulina'' |volume=2016 |article-number=e.T17013A45229114 |doi=10.2305/IUCN.UK.2016-1.RLTS.T17013A45229114.en |access-date=12 November 2021}}</ref> and they can be difficult to tell apart. Compared to the harbour seal, the grey seal has a longer, more sloped snout, a flatter head, and eyes which are set farther apart. The nostrils of the harbour seal form a "V" shape, appearing to meet at the bottom, while the nostrils of the grey seal are more parallel. The grey seal has fewer, larger spots than the harbour seal. Grey seals are often larger than harbour seals, and are about 3 times heavier.<ref>{{cite web|title=How to identify British seals|url=http://www.discoverwildlife.com/british-wildlife/how-identify-british-seals|publisher=BBC Wildlife|access-date=26 March 2026 |archive-date=4 September 2018|archive-url=https://web.archive.org/web/20180904143757/http://www.discoverwildlife.com/british-wildlife/how-identify-british-seals}}</ref><ref name=discover/><ref>{{cite web |last1=Marriott |first1=Emma |title=Spotting the Difference: Seal Species in Scotland |url=https://www.seabird.org/blog/scottishseals |website=Scottish Seabird Centre |access-date=26 March 2026}}</ref>
Wintering hooded seals can be confused with grey seals as they are about the same size and somewhat share a large-nosed look. They can be distinguished by the fact that the hooded seal has a paler base colour and usually evidences a stronger spotting.<ref>{{cite book |editor-last1=Perrin |editor-first1=W. F. |editor-last2=Würsig |editor-first2=B. |editor-last3=Thewissen |editor-first3=J. G. M. |year=2009 |url=https://books.google.com/books?id=2rkHQpToi9sC&q=%22gray%20seal%22%20OR%20%22grey%20seal%22 |title=Encyclopedia of marine mammals |publisher=Academic Press |isbn=978-0-08-091993-5 |chapter=Grey Seal (''Halichoerus gryphus'') |last1=Hall |first1=Ailsa |last2=Thompson |first2=David |pages=500–502}}</ref>
==Distribution and habitat== [[File:Juvenilegreysealswimmingfarneislands.jpg|thumb|alt=Seal head poking out from the sea.|A juvenile swimming in the Farne Islands, UK]] The grey seal is resident to 18 countries: Belgium, Canada, Denmark (including Faroe Islands), Estonia, Finland, France, Germany, Iceland, Ireland, Latvia, Lithuania, the Netherlands, Norway, Poland, Russia, Sweden, the United Kingdom, and the United States of America. It is also an occasional vagrant in Greenland and Portugal. The global population was estimated to be about 632,000 in 2016.<ref name=IUCN/>
In the UK, the most ecologically significant breeding grounds, classified as Special Areas of Conservation (SACs) Grade A/B, are as follows (percentage of annual UK pup production in parentheses): ''Monach Islands'', Outer Hebrides (20%); ''Faray and Holm of Faray'', Orkney (9%); ''North Rona'', Outer Hebrides (5%); ''Isle of May'', Fife (4.5%); ''Treshnish Isles'', Inner Hebrides (3%); ''Berwickshire and North Northumberland Coast'' (2.5%); and ''Pembrokeshire Marine'' (2%).<ref>{{cite web |title=1364 Grey seal ''Halichoerus grypus'' |url=https://sac.jncc.gov.uk/species/S1364/ |website=JNCC |access-date=29 March 2026}}</ref>
Some of the more touristically significant breeding grounds in the UK which aren't SACs include: Blakeney Point and Horsey Beach in Norfolk, various locations in Cornwall, and Donna Nook in Lincolnshire.<ref>{{cite web |title=Where to see seals in the UK |url=https://www.rspca.org.uk/adviceandwelfare/wildlife/seals/watch |website=RSPCA |access-date=29 March 2026}}</ref><ref>{{cite web |title=Britain's best seal watching spots and how to avoid disturbing the colony |url=https://www.countryfile.com/wildlife/marine-life/britains-best-seal-watching-spots |website=BBC Countryfile |access-date=29 March 2026}}</ref><ref>{{cite web |title=Where to go seal watching |url=https://www.nationaltrust.org.uk/visit/coast-beaches/where-to-go-seal-watching |website=National Trust |access-date=29 March 2026}}</ref> Large numbers of grey seals have recently commenced a recolonisation of the tidal section of the River Thames in London; a survey conducted by the ZSL in 2024 found that around 3,000 grey seals were living in the area.<ref>{{Cite web |date=2024-09-27 |title=Thames: Thousands of seals making the estuary their home |url=https://www.bbc.com/news/articles/cly6n7dx00no |access-date=2025-06-14 |website=BBC News |language=en-GB}}</ref> In Ireland, the 5 largest colonies are in order: Inishkea Islands, County Mayo; various islands in Connemara, County Galway; various islands in County Donegal; Blasket Islands, County Kerry; and Saltee Islands, County Wexford.<ref>{{cite journal |last1=Ó Cadhla |first1=Oliver |last2=Keena |first2=Tara |last3=Strong |first3=Dennis |last4=Duck |first4=Callan |last5=Hiby |first5=Lex |title=Monitoring of the breeding population of grey seals in Ireland, 2009 - 2012 |journal=Irish Wildlife Manuals |date=2013 |volume=74 |url=https://www.npws.ie/sites/default/files/publications/pdf/IWM74.pdf |access-date=29 March 2026 |publisher=National Parks and Wildlife Service, Department of the Arts, Heritage and the Gaeltacht}}</ref>
In the German Bight, colonies exist off the islands Sylt, Amrum and on Heligoland.<ref>{{cite web |url=http://www.nordseewolf.de/magazin/13-01-2010/kegelrobben-geburtenrekord-auf-helgoland/ |title=Kegelrobben-Geburtenrekord auf Helgoland |language=de |work=Nordseewolf Magazin |date=13 January 2010 |first=Melanie |last=Hahn |access-date=20 November 2011 |archive-url=https://web.archive.org/web/20160331005018/http://www.nordseewolf.de/magazin/13-01-2010/kegelrobben-geburtenrekord-auf-helgoland/ |archive-date=31 March 2016 }}</ref>
In Iceland, the largest colony is in Breiðafjörður, with 62% of Iceland's pups being born there. Other large colonies can be found on Iceland's northwest coast, in Strandir and Skagafjörður, and the south coast, in Öræfi and Surtsey.<ref name="Iceland pups">{{cite web |last1=Granquist |first1=Sandra M. |title=Population estimate of grey seals (Halichoerus grypus) in Iceland 2022 |url=https://www.hafogvatn.is/is/midlun/utgafa/haf-og-vatnarannsoknir/stofnstaerdarmat-a-utsel-halichoerus-grypus-vid-island-arid-2022 |publisher=Marine and Freshwater Research Institute |date=2024 |ISSN=2298-9137}}</ref>
In Canada, the grey seal is typically found in large numbers in the coastal waters of the Maritime Provinces. It is typically seen in areas such as the Gulf of St. Lawrence, Newfoundland, Prince Edward Island, and Quebec. The largest colony in the world is on Sable Island, Nova Scotia, with an estimated 76,600 pups born in 2021.<ref name="canada pups">{{cite web |last=den Heyen |display-authors=etal |title=Grey Seal Pup Production in Canada |url=https://www.dfo-mpo.gc.ca/csas-sccs/Publications/ResDocs-DocRech/2023/2023_078-eng.html |website=Government of Canada |date=2023}}</ref>
In the US, it is found year-round off the coast of New England, in particular Maine and Massachusetts. There are colonies all along the northern Atlantic coast as far south as New Jersey, and occasional sightings have been reported as far as North Carolina.<ref name=NOAA>{{cite report |title=Gray Seal (Halichoerus grypus grypus): Western North Atlantic Stock |date=April 2014 |publisher=NMFS, NOAA |pages=342–350 |url=https://media.fisheries.noaa.gov/2022-08/Gray%20Seal-W%20North%20Atl%20Stock_SAR%202021.pdf |access-date=2015-06-15 }}</ref> Archaeological evidence confirms grey seals in southern New England with remains found on Block Island, Martha's Vineyard, and near the mouth of the Quinnipiac River in New Haven, Connecticut, and there is a report by Farley Mowat of historic breeding colonies as far south as Cape Hatteras, North Carolina.<ref name=Mowat>{{cite book |last1=Mowat |first1=Farley |title=Sea of Slaughter |publisher=Atlantic Monthly Press Publishing |edition=First American |year=1984 |isbn=0-87113-013-0}}</ref><ref>{{cite journal |title=Gray Seal Remains from Southern New England Archeological Sites |author=Waters, Joseph H. |journal=Journal of Mammalogy |volume=48 |issue=1 |date=February 1967 |pages=139–141 |doi=10.2307/1378182 |jstor=137818}}</ref> Its range is expanding south, with a growing population in North Carolina.<ref name=Carolina>{{cite web |title=Gray Seal - Halichoerus grypus |url=https://auth1.dpr.ncparks.gov/mammals/view.php?species_id=82 |website=Mammals of North Carolina: their Distribution and Abundance |access-date=29 March 2026}}</ref>
[[File:Seals at Nantucket National Wildlife Refuge (5961318725).jpg|thumb|alt=A group of seals, some grey, some brown, and some cream, in various shades.|A large colony at Nantucket National Wildlife Refuge, Massachusetts, USA. Note the wide variety of colours]]
[[File:Grey seals, Stiffkey, Norfolk.jpg|thumb|alt=A group of seals on the beach.|Group of grey seals on sands at Stiffkey, Norfolk]]
{| class="wikitable sortable" |+ Local population numbers of Grey seal<ref name="marine mammals"/> |- ! Region !! Pups born annually !! Year |- | Canada (total) || 98,200 || 2021<ref name="canada pups"/> |- | Canada, Sable Island || 76,600 || 2021<ref name="canada pups"/> |- | UK (total) || 57,000 || 2012 |- | UK, Scotland || 50,000 || 2012 |- | Canada, Gulf of St Lawrence || 16,900 || 2021<ref name="canada pups"/> |- | Europe (total, excluding UK) || 10,700 || n/a |- | UK, Northeast England || 4,900 || 2012 |- | Baltic Sea || 4,700 || 2007 |- | United States || 2,600 || 2008 |- | Ireland || 2,100 || 2012 |- | Norway || 1,300 || 2008 |- | Iceland || 1,550 || 2022<ref name="Iceland pups"/> |- | Russia || 800 || 1994 |- | Wadden Sea || 600 || 2014 |- | Total || 168,850 || n/a |}
==Behaviour==
[[File:GreySealMating.jpg|left|thumb|alt=Smaller cream-coloured seal, left, and larger, brown, wrinkled seal, right, laying on the sand together.|Female (left) and male (right) mating, Donna Nook, England]] [[File:Juvenile Grey Seal.jpg|thumb|alt=Small cream-coloured seal pup with silky fur.|Seal pup a few days after birth, Heligoland, Germany]] thumb|alt=Pure white seal pup.|Pups are often a stark white at birth. They shed their entire coat after about 3 weeks, and their new coat is much darker
Grey seals spend most of their time at sea. They can be seen hauled out on rocks, islands, and shoals not far from shore, occasionally coming ashore to rest.<ref>{{cite web |title=Grey Seal |url=https://www.wildlifetrusts.org/wildlife-explorer/marine/marine-mammals-and-sea-turtles/grey-seal |website=The Wildlife Trusts |access-date=10 April 2026}}</ref> The Baltic subspecies most frequently hauls out at night, beginning right after sunset. This may be related to the behaviour of its main prey species, Atlantic herring, which forms large schools during the day and disperses at night.<ref>{{cite journal |last1=Sjöberg |first1=Mikael |last2=McConnell |first2=Bernie |last3=Fedak |first3=Mike |date=1999 |title=Haulout patterns of grey seals Halichoerus grypus in the Baltic Sea |journal=Wildlife Biology |volume=5 |pages=37–47 |doi=10.2981/wlb.1999.007 |url=https://bioone.org/journals/wildlife-biology/volume-5/issue-1/wlb.1999.007/Haulout-patterns-of-grey-seals-Halichoerus-grypus-in-the-Baltic/10.2981/wlb.1999.007.pdf |access-date=10 April 2026 |publisher=Nordic Board for Wildlife Research}}</ref>
===Reproduction===
Breeding colonies are known as ''rookeries'', and are generally on beaches and remote islands, although in the Baltic and the Gulf of St Lawrence grey seals have been known to occasionally breed on sea ice. Females generally return to the exact location where they were born to give birth, but they sometimes venture to different rookeries.<ref name="marine mammals"/>
Females reach sexual maturity at 3–5 years old, while males reach maturity at 6 years. Males, known as ''bulls'', form a territory on the beach, and can mate with more than 6 females, known as ''cows'', a year. Mating can take place on land or in water. The females are pregnant for about 11 and a half months, and give birth to a single pup at the same time each year. Pups weigh {{cvt|11|–|20|kg}} at birth, and have dense, soft, silky white fur.<ref name=cornish>{{cite web |title=Grey Seals |url=https://www.sealsanctuary.co.uk/greyseals.html |website=Cornish Seal Sanctuary |access-date=10 April 2026}}</ref><ref name="marine mammals"/><ref>{{cite web |title=Autumn spectacle: grey seal colonies |url=https://www.bbc.com/earth/story/20141009-and-they-called-it-pupping-love |website=BBC Earth |access-date=10 April 2026 |archive-url=https://web.archive.org/web/20151102163005/https://www.bbc.com/earth/story/20141009-and-they-called-it-pupping-love |archive-date=2 Nov 2015 |date=10 October 2014}}</ref>
The time of year that pups are born varies depending on the location, landing somewhere between September and March. The earliest pups are born in Ireland and Southwest UK in September. The time at which pups are born along the UK becomes progressively later in a counterclockwise manner; pups are born on the Isles of Scilly and Cornwall in September, in Scotland and the Farne Islands in December, and on the southeast coast in January.<ref name=cornish/><ref name="marine mammals"/> In Canada, pups are born in January, and in the Baltic, pupping is in February or March.<ref name="marine mammals"/>
All parental care is provided by the female. Males do not provide parental care, but they defend females against other males for mating.<ref>{{Cite journal |last1=Bubac |first1=Christine M. |last2=Coltman |first2=David W. |last3=Don Bowen |first3=W. |last4=Lidgard |first4=Damian C. |last5=Lang |first5=Shelley L. C. |last6=den Heyer |first6=Cornelia E. |date=June 2018 |title=Repeatability and reproductive consequences of boldness in female gray seals |journal=Behavioral Ecology and Sociobiology |volume=72 |issue=6 |page=100 |doi=10.1007/s00265-018-2515-5 |bibcode=2018BEcoS..72..100B |s2cid=46975859}}</ref> During lactation, the pups rapidly fatten up on their mothers' extremely fat-rich milk, quadrupling their body weight in 18 days. The milk can consist of up to 60% fat.<ref name="marine mammals"/> After lactation, at about 18–21 days old, they shed their pup fur and grow dense waterproof adult fur, and enter a post-weaning fast for 21 days.<ref>{{cite web |title=What is Lanugo? |url=https://isleofmaynnr.wordpress.com/2020/12/02/what-is-lanugo/ |website=Isle of May National Nature Reserve |access-date=10 April 2026}}</ref><ref name=Bowen>{{Cite journal |last1=Bowen |first1=William D. |last2=Heyer |first2=Cornelia E. den |last3=McMillan |first3=Jim I. |last4=Iverson |first4=Sara J. |date=2015-04-01 |title=Offspring size at weaning affects survival to recruitment and reproductive performance of primiparous gray seals | journal=Ecology and Evolution |volume=5 |issue=7 |pages=1412–1424 |doi=10.1002/ece3.1450 |issn=2045-7758 |pmc=4395171 |pmid=25897381 |bibcode=2015EcoEv...5.1412B }}</ref> After their fast, they leave for the sea to learn to fish for themselves.<ref>{{cite web |title=Grey Seals |url=https://www.sealrescueireland.org/seal-facts/grey-seal-quick-facts/ |website=Seal Rescue Ireland |access-date=10 April 2026}}</ref> The pups are precocial, with mothers returning to the sea to forage once pups are weaned.<ref name=Bowen/> The mother doesn't eat at all while raising their pup, and can lose up to 40% of their weight each breeding season.<ref name="marine mammals"/>
Seal pup first-year survival rates are estimated to vary from 80 to 85%<ref>{{Cite journal | doi=10.1111/j.1365-2656.2001.00468.x |title = Factors affecting first-year survival in grey seals and their implications for life history strategy | journal=Journal of Animal Ecology | volume=70 | pages=138–149 |year = 2008 |last1 = Ailsa j |first1 = Hall | last2=Bernie j | first2=Mcconnell | last3=Richard j | first3=Barker | doi-access=free}}</ref><ref>{{cite journal |url=https://www.researchgate.net/publication/229788805 |doi=10.1111/j.1469-7998.1984.tb06042.x |title=Mortality and morbidity in Grey seal pups (Halichoerus grypus). Studies on its causes, effects on the environment, the nature and sources of infectious agents, and the immunological status of pups |year=1984 |last1=Baker |first1=J. R. |journal=Journal of Zoology |volume=203 |pages=23–48 }}</ref> to below 50%<ref name="friendsofhorseyseals.co.uk">{{Cite web |url=https://www.friendsofhorseyseals.co.uk/ |title=Homepage |website=Friends of Horsey Seals |access-date=19 March 2021}}</ref> depending on location and conditions. Starvation due to difficulties in learning to feed appears to be the main cause of pup death.<ref name="friendsofhorseyseals.co.uk"/>
Male grey seals engage in aggressive sexual behaviour, which can lead to severe injuries and even death for the female. Sometimes they will also target females from other seal species.<ref>{{cite journal |last1=Wilson |first1=Susan C. |title=Attempted Mating between a Male Grey Seal and Female Harbor Seals |journal=Journal of Mammalogy |date=1975 |volume=56 |issue=2 |pages=531–534 |doi=10.2307/1379389 |jstor=1379389 }}</ref> In the North Sea, multiple cases were recorded of pregnant harbour seals dying as a result of forced copulation with male grey seals.<ref>{{cite journal |last1=Rohner |first1=Simon |title=Male grey seal commits fatal sexual interaction with adult female harbour seals in the German Wadden Sea |journal=Scientific Reports |date=2020 |volume=10 |issue=1 |article-number=13679 |doi=10.1038/s41598-020-69986-w |pmid=32792537 |pmc=7426965 }}</ref>
===Communication===
While it was once thought that marine mammals communicate vocally, research conducted by researchers at Monash University shows that grey seals can clap their flippers underwater as a form of communication. This may be used to deter a predator from attacking or to attract a mate. The head researcher, Dr. Burville, had been diving for 17 years in an attempt to capture this behaviour on camera. He stated: "The discovery of 'clapping seals' might not seem that surprising, after all, they're famous for clapping in zoos and aquaria, but where zoo animals are often trained to clap for our entertainment -- these grey seals are doing it in the wild of their own accord."<ref>{{cite journal |last1=Hocking |first1=David P. |last2=Burville |first2=Ben |last3=Parker |first3=William M. G. |last4=Evans |first4=Alistair R. |last5=Park |first5=Travis |last6=Marx |first6=Felix G. |title=Percussive underwater signaling in wild gray seals |journal=Marine Mammal Science |date=31 January 2020 |volume=36 |issue=2 |pages=728–732 |doi=10.1111/mms.12666 |url=https://onlinelibrary.wiley.com/doi/10.1111/mms.12666}}</ref><ref name="sciencedaily.com">{{Cite web|url=https://www.sciencedaily.com/releases/2020/02/200203104510.htm|title=Grey seals discovered clapping underwater to communicate|website=ScienceDaily|access-date=19 March 2021}}</ref>
== Ecology ==
=== Diet ===
[[File:Grey seal food web.png|thumb|left|alt=Illustration of the relations between the grey seal and its prey.|Grey seal food web in the Baltic Sea<ref>{{cite journal |last1=Karlson |first1=A.M. |last2=Gorokhova |first2=E. |last3=Gårdmark |first3=A. |last4=Pekcan-Hekim |first4=Z. |last5=Casini |first5=M. |last6=Albertsson |first6=J. |last7=Sundelin |first7=B. |last8=Karlsson |first8=O. |last9=Bergström |first9=L. |year=2020 |title=Linking consumer physiological status to food-web structure and prey food value in the Baltic Sea |journal=Ambio |volume=49 |issue=2 |pages=391–406 |doi=10.1007/s13280-019-01201-1|pmid=31168701 |pmc=6965491 |bibcode=2020Ambio..49..391K }}</ref>]] thumb|alt=Grey seal on a wooden pier, being fed a fish by a zookeeper.|Captive grey seal being fed
The grey seal feeds on a wide variety of fish, mostly benthic or demersal species, taken at depths down to 70 m (230 ft) or more. Sand eels (''Ammodytes spp'') are important in its diet in many localities. Cod and other gadids, flatfish, herring,<ref>{{cite web|url=http://www.ices.dk/sites/pub/CM%20Doccuments/CM-2007/C/C1207.pdf|title=How does hunting grey seals (Halichoerus grypus) on Bothnian Bay spring ice influence the structure of seal and fish stocks? |first=Olavi |last=Stenman |year=2007 |publisher=International Council for the Exploration of the Sea |access-date=23 January 2017 |quote=Analysis of fish otolithes and other hard particles in the alimentary tract showed clearly that the herring (''Clupea harengus'') was the most important item of prey.}}</ref> wrasse<ref>{{cite journal |last1= Ridoux|first1=Vincent|last2=Spitz |first2= J.|last3= Vincent|first3=Cecile |last4=Walton |first4=M. J. |date= 2007|title=Grey seal diet at the southern limit of its European distribution: combining dietary analyses and fatty acid profiles |url=http://archimer.ifremer.fr/doc/2007/publication-3573.pdf |journal= Journal of the Marine Biological Association of the United Kingdom|volume= 87|issue=1 |pages=255–264 |doi=10.1017/S002531540705463X |bibcode=2007JMBUK..87..255R |s2cid=55465507|access-date=24 January 2017 }}</ref> and skates<ref>{{cite book|first1=Claude |last1=Savenkoff |first2=Lyne |last2=Morissette |first3=Martin |last3=Castonguay |first4=Douglas P. |last4=Swain |first5=Mike O. |last5=Hammill |first6=Denis |last6=Chabot |first7=J. Mark |last7=Hanson|title=Ecosystem Ecology Research Trends |chapter=Interactions between Marine Mammals and Fisheries: Implications for Cod Recovery |editor1-first=Junying |editor1-last=Chen |editor2-first=Chuguang |editor2-last=Guo|publisher=Nova Science Publishers |year=2008 |isbn=978-1-60456-183-8 |page=130 |chapter-url=https://books.google.com/books?id=AH9JghsCN0gC&pg=PA130}}</ref> are also important locally. However, it is clear that the grey seal will eat whatever is available, including octopus<ref>{{cite web|url=http://www.bbc.co.uk/wales/nature/sites/species/mammals/grey_seals.shtml|title=Grey seal |work=Wales Nature & Outdoors |publisher=BBC Wales |date=25 February 2011 |access-date=20 November 2011}}</ref> and lobsters.<ref>{{cite web|url=http://www.askaboutireland.ie/reading-room/environment-geography/flora-fauna/flora-and-fauna-of-wexfor/fauna-of-the-wexford-slob/the-grey-seal/ |title=The Grey Seal |work=Ask about Ireland |access-date=20 November 2011}}</ref> The average daily food requirement is estimated to be 5 kg (11 lb), though the seal does not feed every day and it fasts during the breeding season.
Observations and studies from Scotland, The Netherlands, and Germany show that grey seals will also prey and feed on large animals like harbour seals and harbour porpoises.<ref>{{cite journal|title=Exposing the grey seal as a major predator of harbour porpoises |first1=Mardik F. |last1=Leopold |first2=Lineke |last2=Begeman |first3=Judith D. L. |last3=van Bleijswijk |first4=Lonneke L. |last4=IJsseldijk |first5=Harry J. |last5=Witte |first6=Andrea |last6=Gröne |journal=Proceedings of the Royal Society |volume=282 |issue=1798|article-number=20142429 |year=2014|doi=10.1098/rspb.2014.2429 |pmid=25429021 |pmc=4262184 }}</ref><ref>{{cite journal|title=Grey seal (''Halichoerus grypus'') predation on harbour seals (''Phoca vitulina'') on the island of Helgoland, Germany |first1=Abbo |last1=van Neer |first2=Lasse F. |last2=Jensen |first3=Ursula |last3=Siebert |journal=Journal of Sea Research |volume=97 |doi=10.1016/j.seares.2014.11.006 |pages=1–4|year=2015 |bibcode=2015JSR....97....1V }}</ref><ref>{{cite news |title=Kegelrobben mit großem Appetit auf Schweinswale |trans-title=Grey seals with a great appetite for porpoises |language=de |first=Angelika |last=Hillmer |work=Hamburger Abendblatt |date=16 February 2015}}</ref> In 2014, a male grey seal in the North Sea was documented and filmed killing and cannibalising 11 pups of his own species over the course of a week. Similar wounds on the carcasses of pups found elsewhere in the region suggest that cannibalism and infanticide may not be uncommon in grey seals. Male grey seals may engage in such behaviour potentially as a way of increasing reproductive success through access to easy prey without leaving prime territory.<ref>{{cite web|url=https://www.newscientist.com/article/2077441-first-video-footage-of-seal-drowning-and-eating-a-pup/ |title=First video footage of seal drowning and eating a pup |website=New Scientist |date=15 February 2016 |last1=Gabbatiss |first1=Josh}}</ref><ref>{{cite journal |last1=Bishop |first1=A. M. |title=Cannibalism by a male grey seal (Halichoerus grypus) in the North Sea Cannibalism by a male grey seal (Halichoerus grypus) in the North Sea |journal=Aquatic Mammals |date=2016 |volume=42 |issue=2 |pages=137–143 |doi=10.1578/AM.42.2.2016.137 |url=https://www.aquaticmammalsjournal.org/cannibalism-by-a-male-grey-seal-halichoerus-grypus-in-the-north-sea/|url-access=subscription }}</ref>
In 2026, a number of instances of grey seals being recorded hunting, killing and partially eating common dolphins (''Delphinus delphis'') off the coasts of Devon and West Wales, as well as in the Irish Sea, were recorded. It is currently not known why the seals are hunting dolphins; however, it has been theorised that the attacks may be the work of a single population or family of seals operating between North Devon and the Welsh coastline. The seals may also be shifting from hunting harbour porpoises to common dolphins due to the latter species undergoing a significant population increase, becoming the most common species of cetacean in the area where the attacks are taking place.<ref>{{Cite web |date=2026-02-27 |title=Bloodthirsty seals are killing and EATING dolphins off British coast and experts have no idea why {{!}} Need To Know |url=https://needtoknow.co.uk/2026/02/27/bloodthirsty-seals-are-killing-and-eating-dolphins-off-british-coast-and-experts-have-no-idea-why/ |access-date=2026-03-02 |language=en-GB}}</ref>
=== Predators ===
Grey seals are vulnerable to the typical predators of seals; their primary predator is the orca. Certain large species of sharks are known to prey on grey seals in North American waters, particularly great white sharks and bull sharks. Some grey seal carcasses have washed ashore with visible "cookie cutter" bite marks, a telltale sign of attack by a Greenland shark.<ref>{{cite journal | url=https://cdnsciencepub.com/doi/abs/10.1139/f83-040 | doi=10.1139/f83-040 | title=Predation by Sharks on the Grey Seal (Halichoerus grypus) in Eastern Canada | year=1983 | last1=Brodie | first1=Paul | last2=Beck | first2=Brian | journal=Canadian Journal of Fisheries and Aquatic Sciences | volume=40 | issue=3 | pages=267–271 | bibcode=1983CJFAS..40..267B | url-access=subscription }}</ref><ref>{{cite journal |last1=Lucas |first1=Z. N. |last2=Natanson |first2=L. J. |year=2010 |url=https://ojs.library.dal.ca/nsis/article/view/3987 |title=Two shark species involved in predation on seals at Sable Island, Nova Scotia, Canada |journal=Proceedings of the Nova Scotian Institute of Science |volume=45 |issue=2 |pages=64–88}}</ref> In the waters of Great Britain, grey seals are a common prey species for orcas.<ref>{{cite journal |last1=Weir |first1=C. R. |year=2002 |title=Killer whales (''Orcinus orca'') in UK waters |journal=British Wildlife |volume=14 |issue=2 |pages=106–108 |url=https://www.researchgate.net/publication/237714054}}</ref><ref>{{cite journal |last1=Bloc |first1=D. |last2=Lockyer |first2=C. |year=1988 |title=Killer whales (''Orcinus area'') in Faroese waters |journal=Rit Fiskideildar}}</ref> In the Baltic, grey seal pups are prey for White-tailed eagles and Great black-backed gulls.<ref name=IUCN/>
=== Pests and diseases ===
In a study of 38 adult grey seal bodies stranded on the coasts of England and Wales, the most common cause of death was bacterial pneumonia. The most common cause of pneumonia was ''Streptococcus spp.''. Notably, most of the seals had incidental non-fatal parasitic diseases; 76% of the seals had nematodes in their stomachs, 66% had Acanthocephala infections, and 37% had mites in their nose.<ref>{{cite journal |last1=Baker |first1=J. R. |last2=Jepson |first2=P. D. |last3=Simpson |first3=V. R. |last4=Kuiken |first4=T. |title=Causes of mortality and non-fatal conditions among grey seals (Halichoerus grypus) found dead on the coasts of England, Wales and the Isle of Man |journal=Veterinary Record |date=30 May 1998 |volume=142 |issue=22 |pages=595–601 |doi=10.1136/vr.142.22.595 |url=https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vr.142.22.595|url-access=subscription }}</ref>
==Relationship with humans== [[File:A hunted grey seal 1961 (JOKAKAL3B-12006).tif|thumb|alt=Black-and-white image of a seal tied to a plank of wood.|A hunted grey seal, 1961, Finland]] ===Hunting and culling=== Grey seals were nearly extirpated in the United States from hunting for oil, meat, and skins. Bounties were paid on all kinds of seals up until 1945 in Maine and 1962 in Massachusetts.<ref name=Lelli>{{cite journal |title=Seal Bounties in Maine and Massachusetts, 1888 to 1962 |author=Barbara Lelli |author2=David E. Harris |author3=AbouEl-Makarim Aboueissa |name-list-style=amp |journal=Northeastern Naturalist |volume=16 |issue=2 |pages=239–254 |year=2009 |doi=10.1656/045.016.0206|s2cid=85652019 }}</ref> In 2013, there were calls by fishermen in Cape Cod to cull the rising grey seal population, over concerns it was harming the local cod catch.<ref>{{cite news |last1=Bidggod |first1=Jess |date=16 August 2013 |url=https://www.nytimes.com/2013/08/17/us/thriving-in-cape-cods-waters-gray-seals-draw-fans-and-foes.html |title=Thriving in Cape Cod's Waters, Gray Seals Draw Fans and Foes |work=The New York Times}}</ref>
In 2012, there was a controversial suggestion to cull 70,000 grey seals in the Gulf of St. Lawrence. This was spurred by predictions that the local cod population would be extirpated, with the primary cause attributed to grey seals. However, as of 2026, no such cull has taken place.<ref>{{cite news |url=https://www.cbc.ca/news/canada/newfoundland-labrador/plan-to-cull-70-000-grey-seals-gets-senate-panel-s-approval-1.1221876 |title=Plan to cull 70,000 grey seals gets Senate panel's approval |location=Newfoundland & Labrador |work=CBC News |date=23 October 2012}}</ref><ref>{{cite web |last1=Skerritt |first1=Daniel |title=What lives, what dies? The role of science in the decision to cull seals to save cod |url=https://theconversation.com/what-lives-what-dies-the-role-of-science-in-the-decision-to-cull-seals-to-save-cod-131298 |website=The Conversation |access-date=24 March 2026 |date=March 15, 2020}}</ref>
In 2009, the EU banned the import and sale of seal-based products, including grey seal.<ref>{{cite web |title=Regulation (EC) No 1007/2009 on trade in seal products |url=http://data.europa.eu/eli/reg/2009/1007/oj |website=EUR-Lex |date=31 Oct 2009}}</ref> As of 2026, grey seal hunting is legal in all countries on the Baltic Sea.<ref name="Sweden quota">{{cite web |title=Decision on seal hunting - more seals will be shot than last year |url=https://swedenherald.com/article/decision-on-seal-hunting-more-seals-will-be-shot-than-last-year |website=Sweden Herald |access-date=24 March 2026}}</ref> As of 2024, about 1,500 Baltic grey seals are killed annually.<ref>{{cite web |title=Scientists warn: The grey seal hunt is too large |url=https://www.sciencedaily.com/releases/2024/03/240327124728.htm |website=ScienceDaily |access-date=11 April 2026 |date=27 March 2024}}</ref> Between 2019–2022, 3,774 grey seals were hunted in Sweden, making it the largest hunter of seals in the EU.<ref>{{cite web |title=Trade in seal products |url=https://environment.ec.europa.eu/topics/nature-and-biodiversity/trade-seal-products_en |website=European Commission |access-date=11 April 2026}}</ref> In 2026, the quota for grey seals in Sweden was 1,350 — up from 1,000 the previous year.<ref name="Sweden quota"/>
In Norway, grey seal hunting is legal, and seals are hunted as game. In Iceland, grey seal hunting is banned, however, a license can be issued for personal, subsistence hunting. There is no tradition of grey seal hunting in the Faroe Islands, where there has been virtually no seal hunting since the 1960s.<ref>{{cite web |title=Grey seal |url=https://nammco.no/grey-seal/ |website=NAMMCO |access-date=11 April 2026 |date=July 2023}}</ref>
Seal hunting is not a common practice in the UK,<ref>{{cite web |title=Culling/Hunting of Seals and the legislation/licencing |url=https://anglingtrust.net/predation-2/seals-around-the-british-isles/culling-hunting-of-seals-and-the-legislation-licencing/ |website=Angling Trust |access-date=24 March 2026}}</ref> where it is illegal to kill seals.<ref>{{cite web |last1=Sayer |first1=Sue |title=Our enigmatic seals are poorly protected by UK legislation, we’re supporting MPs’ recommendations to address this |url=https://www.wcl.org.uk/our-enigmatic-seals-are-poorly-protected-by-uk-legislation.asp |website=Wildlife and Countryside Link |access-date=24 March 2026 |date=July 2023 |quote=Across the UK, seal legislation is neither simple nor consistent. Both native species are fully protected by law from killing and intentional or reckless disturbance in Northern Ireland. In Scotland it is an offence to kill, injure, take and harass a seal at 194 designated seal haul out sites. In England and Wales it is illegal to kill, injure and take a seal, but there is no protection from intentional and reckless disturbance.}}</ref> However, licenses can be granted for culling in specific circumstances. Culling regulations in the UK as a whole are governed by the Conservation of Seals Act 1970, however each individual region can decide its own laws. In England, Wales, and Scotland, licenses to cull seals can be granted to protect flora and fauna, to reduce population surplus, and to protect public safety.<ref>{{cite web |title=Conservation of Seals Act 1970 |url=https://www.legislation.gov.uk/ukpga/1970/30?view=extent |website=UK Legislation |access-date=24 March 2026}}</ref> In 2021, the Marine (Scotland) Act was amended, which repealed the ability to grant licenses for prevention of damage to Scottish fish farms.<ref>{{cite web |title=Marine (Scotland) Act 2010 |url=https://www.legislation.gov.uk/asp/2010/5 |website=UK legislation |access-date=24 March 2026}}</ref> In Scotland, 62 grey seals were legally shot under license in 2020.<ref>{{cite web |title=Seal licensing |url=https://www.gov.scot/collections/marine-licensing-seal-licensing/ |website=Scottish Government |access-date=24 March 2026}}</ref>
In 2022, the Cornish Mackerel Fishermen group called for a cull in Cornwall, referring to grey seals as "rats of the sea". This was met with heavy backlash from marine conservation groups.<ref>{{cite web |last1=Horton |first1=Helena |title=‘Rats of the sea’: backlash after Cornish fishers call for seal cull |url=https://www.theguardian.com/environment/2022/apr/25/rats-of-the-sea-backlash-after-cornish-fishers-call-for-seal-cull |website=The Guardian |date=25 Apr 2022}}</ref>
===Conservation and recovery=== [[File:Monitoring grey seals in Pembrokeshire, Wales.webm|thumb|left|alt=Video.|A short video on monitoring and conservation of grey seals on Skomer Island, Wales]] After near extirpation in the United States, sightings began to increase in the late 1980s.<ref name=Lelli/> One year after Congress passed the 1972 Marine Mammal Protection Act preventing the harming or harassing of seals, a survey of the entire Maine coast found only 30 grey seals.<ref name=Lelli/> At first grey seal populations increased slowly but then rebounded from islands off Maine to Monomoy Island and Nantucket Island off of southern Cape Cod. The southernmost breeding colony was established on Muskeget Island with five pups born in 1988 and over 2,000 counted in 2008.<ref name=Wood/> According to a genetics study, the United States population has formed as a result of recolonisation by Canadian seals.<ref name=Wood>{{cite journal |title=The genetics of recolonization: an analysis of the stock structure of grey seals (Halichoerus grypus) in the northwest Atlantic |journal=Canadian Journal of Zoology |year=2011 |volume=89 |issue=6 |pages=490–497 |doi=10.1139/z11-012|last1=Wood |first1=S.A. |last2=Frasier |first2=T.R. |last3=McLeod |first3=B.A. |last4=Gilbert |first4=J.R. |last5=White |first5=B.N. |last6=Bowen |first6=W.D. |last7=Hammill |first7=M.O. |last8=Waring |first8=G.T. |last9=Brault |first9=S. |bibcode=2011CaJZ...89..490W }}</ref> By 2009, thousands of grey seals had taken up residence on or near popular swimming beaches on outer Cape Cod, resulting in sightings of great white sharks drawn close to shore to hunt the seals.<ref>{{cite news |url=http://archive.boston.com/news/science/articles/2009/10/03/gray_seals_haul_out_to_new_england_waters_again/ |title=Once again, coastal waters getting seals' approval |work=The Boston Globe |date=3 October 2009 |last1=Daley |first1=Beth}}</ref> A count of 15,756 grey seals in southeastern Massachusetts coastal waters was made in 2011 by the National Marine Fisheries Service.<ref name=NOAA/> In 1997, a grey seal was recorded for the first time in North Carolina.<ref name=Carolina/> Grey seals are being seen increasingly in New York and New Jersey waters.<ref name=NOAA/>
The Canadian population was estimated to be 366,400 in 2021, increasing at an average rate of 1.5% per year in 2016–2021. However, the rate of population increase has declined in recent years, and 2021 was the first time in 60 years that the amount of pups being born on Sable Island had decreased.<ref>{{cite web |title=Stock assessment of Northwest Atlantic grey seals (Halichoerus grypus) in Canada in 2021 |url=https://www.dfo-mpo.gc.ca/csas-sccs/Publications/SAR-AS/2022/2022_018-eng.html |website=Government of Canada |access-date=12 April 2026}}</ref>
Grey seal populations have been expanding rapidly in the UK, likely owing to changes in food availability due to climate change. There are now an estimated 157,000 individuals in the wild.<ref>{{cite web |last1=Davis |first1=Katrina |last2=Bevan |first2=Richard |title=Comment: Grey seals |url=https://www.ncl.ac.uk/press/articles/archive/2023/04/conversationgreyseals/ |website=Newcastle University |access-date=12 April 2026 |date=6 April 2023}}</ref>
The Icelandic population was estimated to be 6,697 in 2022; this is a 27% decrease from 1982. However, population numbers have remained relatively unchanged since 2005.<ref name="Iceland pups"/>
The population in the Baltic Sea increased about 8% per year between 1990 and the mid-2000s, with the numbers becoming stagnant since 2005. Some anthropogenic causes of death include drowning in fishing gear and hunting.<ref>{{cite web |title=Health Assessment in the Baltic grey seal (''Halichoerus grypus'') |work=HELCOM Indicator Fact Sheets 2011 |first1=Britt-Marie |last1=Bäcklin |first2=Charlotta |last2=Moraeus |first3=Mervi |last3=Kunnasranta |first4=Marja |last4=Isomursu |publisher=HELCOM |date=2 September 2011 |url=http://www.helcom.fi/BSAP_assessment/ifs/ifs2011/en_GB/BalticGreySeal |archive-url=https://web.archive.org/web/20111103030646/http://www.helcom.fi/BSAP_assessment/ifs/ifs2011/en_GB/BalticGreySeal/ |archive-date=3 November 2011 }}</ref>
Seal rescue groups often take in malnourished pups abandoned by their mothers.<ref>{{cite web |last1=Jagger |first1=Samantha |title=Released seal pups gave helpers 'final farewell' |url=https://www.bbc.com/news/articles/cj60rdn3r0po |website=BBC |access-date=11 April 2026}}</ref> Human noise pollution continues to affect marine-life communication but remains an understudied facet of marine conservation efforts. In more recent years, the potential negative effect of human noise has been highlighted with the discovery of seals using clapping as a form of communication.<ref name="sciencedaily.com"/> In Northern Ireland, it is illegal to intentionally or recklessly disturb a seal.<ref>{{cite web |title=Wildlife and Natural Environment Act (Northern Ireland) 2011 |url=https://www.legislation.gov.uk/nia/2011/15}}</ref>
===In captivity=== Grey seals are adaptable to life in captivity, and are commonly found as zoo animals around their native range, particularly in Europe.<ref>{{cite journal |last1=Łypik |first1=Oliwia |last2=Zieliński |first2=Damian |title=Environmental enrichment for grey seals (Halichoerus grypus) in captive environment |journal=Journal of Animal Science, Biology and Bioeconomy |date=30 Mar 2022 |volume=38 |doi=10.24326/jasbb.2022.1.4 |url=https://czasopisma.up.lublin.pl/jasbb/article/view/4495|doi-access=free }}</ref> Grey seals need a minimum of {{cvt|30|sqm}} land area and {{cvt|120|sqm}} pool area with a minimum depth of {{cvt|2.3|m}}. Caution needs to be taken when handling grey seals, as they are capable of delivering strong bites.<ref>{{cite web |last1=Gili |first1=Claudia |last2=Meijer |first2=Gerard |last3=Lacave |first3=Geraldine |title=EAZA and EAAM BEST PRACTICE GUIDELINES FOR OTARIIDAE AND PHOCIDAE |url=https://strapi.eaza.net/uploads/EAZA_EAAM_Pinniped_Guidelines_approved_701197aefb.pdf |website=European Association of Zoos and Aquaria |access-date=26 March 2026 |date=August 2018}}</ref>
===Seal watching=== Seal watching is a popular activity, with strong economic and touristic benefits. 80,000 people are estimated to visit Horsey Beach for seal watching each year. Seals are the third biggest reason why people visit the Scottish coast for wildlife viewing. In 2003, researchers estimated the economic value of grey seal tourism in Southwest England to be £526,000 per year ({{Inflation|UK|526000|2003|fmt=eq|cursign=£|r=-3}}).<ref>{{cite web |title=Benefits of seal watching for UK coastal tourism |url=https://www.wcl.org.uk/docs/assets/uploads/WCL_Seal_Tourism_Briefing.pdf |website=Wildlife and Countryside Link |access-date=12 April 2026 |date=August 2021}}</ref>
Care must be taken that seal watching does not disturb the seals. The biggest cause of seal watching related disturbance is private watercrafts.<ref>{{cite journal |last1=Curtin |first1=Susanna |last2=Richards |first2=Steven |last3=Westcott |first3=Stephen |title=Tourism and grey seals in south Devon: management strategies, voluntary controls and tourists’ perceptions of disturbance |journal=Current Issues in Tourism |date=2009 |volume=12 |issue=1 |pages=59–81 |doi=10.1080/13683500802295663 |url=https://www.tandfonline.com/doi/abs/10.1080/13683500802295663|url-access=subscription }}</ref> Dogs walked by seal-watchers can cause seals to stampede and suddenly enter water, where they can experience thermal shock.<ref>{{cite web |last1=McIlwraith |first1=Euan |title=Sightseers 'causing undue seal stress' in Aberdeenshire |url=https://www.bbc.com/news/uk-scotland-north-east-orkney-shetland-47804154 |website=BBC |access-date=12 April 2026 |date=4 April 2019}}</ref> At Blakeney Point, which is cordoned off during pupping season, a webcam has been installed, to allow for seal watching without the possibility of disturbance.<ref>{{cite web |last1=Gordon-Farleigh |first1=Neve |title=Webcam installed to livestream grey seal pup births |url=https://www.bbc.com/news/articles/c3979k04rmmo |website=BBC |access-date=12 April 2026 |date=20 November 2025}}</ref>
==References== {{Reflist}}
==External links== {{Commons}} {{Wikispecies|Halichoerus grypus}} {{Portal|Marine life|Mammals}} *[http://www.bbc.co.uk/wales/nature/mediaexplorer/?theme_group=species&theme=mammals&set=seal BBC Wales Nature: Grey Seal video clips] *[http://www.pinnipeds.org/seal-information/species-information-pages/the-phocid-seals/grey-seal Grey Seals on pinnipeds.org] *[https://web.archive.org/web/20060211161126/http://www.arkive.org/species/ARK/mammals/Halichoerus_grypus/ ARKive – images and movies of the grey seal from Atlantic ''(Halichoerus grypus)''] *[http://www.greyseal.net Grey Seal Conservation Society (GSCS)] *[https://www.youtube.com/watch?v=2HI1kB3n5F4 The first filming of the grey seal in Eastern Crimea, Ukraine] * {{sealifephotos|137080}}
{{Carnivora|C1.}} {{Pan-Pinnipedia|P.|state=autocollapse}} {{Taxonbar|from=Q27370}} {{Authority control}}
Category:Phocins Category:Pinnipeds of the Arctic Ocean Category:Pinnipeds of Europe Category:Fauna of the Baltic Sea Category:Fauna of the North Sea Category:Fauna of Scandinavia Category:Mammals of Iceland Grey seal Category:Pinnipeds of North America Category:Fauna of the Holarctic realm Category:Habitats Directive species