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Harbor Seal

Phoca vitulina

Mammal · family Phocidae · order Carnivora

  1. G1
    Critically imperiled
  2. G2
    Imperiled
  3. G3
    Vulnerable
  4. G4
    Apparently secure
  5. G5
    Secure

NatureServe global rank G5: secure[2].

Updated October 30, 2026. Published by Humblebee.

Endangered Species Act
Not listed[1]
NatureServe global rank
G5 Secure[2]
Native in
14 states[3]
Longest recorded life
47.6 years[4]

The Harbor Seal (Phoca vitulina) is a mammal in the family Phocidae, which is part of the order Carnivora[5]. NatureServe ranks it G5 (Secure) worldwide, and it is not listed under the US Endangered Species Act[2][1].

Conservation status

NatureServe gives the Harbor Seal a global rank of G5 (Secure) and a national rank in the United States of N5 (Secure)[2][6]. The IUCN Red List category recorded by NatureServe is Least concern[7]. The seal is not listed as endangered or threatened under the US Endangered Species Act in USFWS data[1]. NatureServe notes that numbers are falling quickly in some regions and rising in others[8].

Status Value
Endangered Species Act[1] Not listed
NatureServe global rank[2] G5 (Secure)
NatureServe US rank[6] N5 (Secure)
IUCN Red List (via NatureServe)[7] Least concern
Total population (NatureServe estimate)[9] 10,000 to >1,000,000 individuals

Where Harbor Seal lives

NatureServe lists the Harbor Seal as native in 14 US states and territories: Alaska, California, Connecticut, Delaware, Florida, Massachusetts, Maine, North Carolina, New Hampshire, New Jersey, New York, Oregon, Rhode Island and Washington[3]. That is where the species is recorded, not a promise that you will see one there[3]. NatureServe also gives each state its own rank, shown in the table on this page[10].

Alaska: native, state rank S4AKMaine: native, state rank S5MEWisconsin: not recordedWIVermont: not recordedVTNew Hampshire: native, state rank S4NNHWashington: native, state rank S4WAIdaho: not recordedIDMontana: not recordedMTNorth Dakota: not recordedNDMinnesota: not recordedMNIllinois: not recordedILMichigan: not recordedMINew York: native, state rank S3NYMassachusetts: native, state rank S4MAOregon: native, state rank S4ORNevada: not recordedNVWyoming: not recordedWYSouth Dakota: not recordedSDIowa: not recordedIAIndiana: not recordedINOhio: not recordedOHPennsylvania: not recordedPANew Jersey: native, state rank S4NNJConnecticut: native, state rank SNACTRhode Island: native, state rank SNRRICalifornia: native, state rank SNRCAUtah: not recordedUTColorado: not recordedCONebraska: not recordedNEMissouri: not recordedMOKentucky: not recordedKYWest Virginia: not recordedWVVirginia: not recordedVAMaryland: not recordedMDDelaware: native, state rank SNADEArizona: not recordedAZNew Mexico: not recordedNMKansas: not recordedKSArkansas: not recordedARTennessee: not recordedTNNorth Carolina: native, state rank SNANCSouth Carolina: not recordedSCDistrict of Columbia: not recordedDCOklahoma: not recordedOKLouisiana: not recordedLAMississippi: not recordedMSAlabama: not recordedALGeorgia: not recordedGAHawaii: not recordedHITexas: not recordedTXFlorida: native, state rank SNRFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[10].
Show state ranks (14 states)
StateRankMeaning
AlaskaS4Apparently Secure
CaliforniaSNRNot Ranked
ConnecticutSNANot Applicable
DelawareSNANot Applicable
FloridaSNRNot Ranked
MaineS5Secure
MassachusettsS4Apparently Secure
New HampshireS4NApparently Secure (nonbreeding)
New JerseyS4NApparently Secure (nonbreeding)
New YorkS3Vulnerable
North CarolinaSNANot Applicable
OregonS4Apparently Secure
Rhode IslandSNRNot Ranked
WashingtonS4Apparently Secure

Habitat

Harbor Seals live along the coast in bays, harbors, river mouths and nearshore waters[11][12]. They are found most often in sheltered places such as bays and inlets, and in smaller numbers along plain open coastlines[12]. They rest on mudbanks, rocky or sandy shores, ledges uncovered at low tide, reefs and sometimes piers[12]. Pups are born on shore, often in places away from strong waves[12].

Habitat types recorded by NatureServe[11]

Size, diet and lifespan

Newly weaned pups eat mostly bottom-dwelling crustaceans, while older seals eat a mix of fish and some squid-like animals and crustaceans[13]. EltonTraits estimates the diet at 80% fish and 20% invertebrates[14]. NatureServe records a typical length of 170 cm (67 in) and a typical adult weight of 136 kg (300 lb)[15][16]. Females usually have one pup at a time[17]. The oldest known Harbor Seal in the AnAge database lived a long life in captivity, and this is a record[4].

Trait Value
Typical length[15] 170 cm (67 in)
Typical adult weight[16] 136 kg (300 lb)
Longest recorded lifespan (AnAge)[4] 47.6 years (captivity)
Litter or clutch size[17] 1
Gestation or incubation[18] 253 days
Female maturity[19] 1,095 days (about 3.0 years)
Food habits[20] Piscivore, Invertivore
Active[21] crepuscular, diurnal
Migration[22] non-migrant, local migrant, long-distance migrant

Estimated diet composition (EltonTraits 1.0)[14]

  • 80% fish
  • 20% invertebrates

When to look for it

Harbor Seals are active at dawn and dusk and during the day, and tides and weather guide their routine[23][21]. They usually rest on shore or on rocks that the low tide uncovers[23]. In some areas they make seasonal trips that can cover several hundred kilometers, while in other areas they stay put[24][22]. Records on GBIF peak in May, June and July, which reflects when people look and report, not how many animals there are[25].

January: 3,549 recordsJanFebruary: 2,985 recordsFebMarch: 4,094 recordsMarApril: 6,337 recordsAprMay: 8,776 recordsMayJune: 9,769 recordsJunJuly: 8,570 recordsJulAugust: 7,753 recordsAugSeptember: 5,654 recordsSepOctober: 3,563 recordsOctNovember: 2,859 recordsNovDecember: 2,291 recordsDec
US observation records on GBIF by month, all years. The three months with the most records are highlighted. Records show when people look and report, not how many animals there are[25].
Show records by month
MonthRecords
January3,549
February2,985
March4,094
April6,337
May8,776
June9,769
July8,570
August7,753
September5,654
October3,563
November2,859
December2,291

Where to see it

National Park Service species lists record Harbor Seal as present in 17 park units[26]. Present means the park has a confirmed record, not that sightings are common.

States with the most GBIF observation records: Maine, California, Washington, Alaska, Oregon[27]. These counts follow where people look and report, not population size.

Questions people ask

Is the Harbor Seal endangered?
It is not listed as endangered or threatened under the US Endangered Species Act[1]. NatureServe ranks it G5 (Secure) globally and N5 (Secure) in the United States, and it is not listed under the US Endangered Species Act[2][6][1].
Where do Harbor Seals live in the US?
NatureServe lists them as native in 14 states and territories, from Alaska and Washington down the Pacific coast and from Maine down the Atlantic coast to Florida[3].
What do Harbor Seals eat?
Older seals eat mostly fish along with some squid-like animals and crustaceans, and one estimate puts the diet at 80% fish and 20% invertebrates[13][14].
How big is a Harbor Seal?
NatureServe records a typical length of 170 cm (67 in) and a typical adult weight of 136 kg (300 lb)[15][16].
How long do Harbor Seals live?
The oldest known Harbor Seal in the AnAge database lived a long life in captivity, and this is a record, not a typical lifespan[4].

Facts and sources

  1. Harbor Seal is not listed as endangered or threatened under the US Endangered Species Act in USFWS ECOS data (checked 2026-10-30). USFWS ECOS
  2. NatureServe global conservation status rank for Harbor Seal: G5 (Secure). NatureServe Explorer
  3. NatureServe lists Harbor Seal as native in 14 US states and territories: Alaska, California, Connecticut, Delaware, Florida, Massachusetts, Maine, North Carolina, New Hampshire, New Jersey, New York, Oregon, Rhode Island, Washington. NatureServe Explorer
  4. Maximum recorded lifespan in AnAge: 47.6 years in captivity. This is a record, not a typical lifespan. AnAge
  5. Harbor Seal (Phoca vitulina) is a mammal in the family Phocidae, order Carnivora. NatureServe Explorer
  6. NatureServe national rank in the United States: N5 (Secure). NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Least concern. NatureServe Explorer
  8. NatureServe notes on trend for Harbor Seal. NatureServe Explorer
  9. NatureServe estimate of total adult population (global, as a range): 10,000 to >1,000,000 individuals. NatureServe Explorer
  10. NatureServe state ranks for Harbor Seal (map and table on this page). NatureServe Explorer
  11. Habitat types NatureServe records for Harbor Seal: Bare rock/talus/scree, Big river, Deep water, Bay/sound, River mouth/tidal river, Tidal flat/shore, Near shore. NatureServe Explorer
  12. NatureServe notes on habitat for Harbor Seal. NatureServe Explorer
  13. NatureServe notes on food for Harbor Seal. NatureServe Explorer
  14. Estimated diet composition in EltonTraits 1.0: 80% fish, 20% invertebrates. EltonTraits 1.0
  15. Typical length recorded by NatureServe: 170 cm (67 in). NatureServe Explorer
  16. Typical adult weight recorded by NatureServe: 136 kg (300 lb). NatureServe Explorer
  17. Typical litter or clutch size in AnAge: 1. AnAge
  18. Gestation or incubation period in AnAge: 253 days. AnAge
  19. Age at female sexual maturity in AnAge: 1,095 days (about 3.0 years). AnAge
  20. Adult food habits recorded by NatureServe: Piscivore, Invertivore. NatureServe Explorer
  21. Activity time in EltonTraits 1.0: crepuscular, diurnal. EltonTraits 1.0
  22. NatureServe migration category for Harbor Seal: non-migrant, local migrant, long-distance migrant (populations can differ). NatureServe Explorer
  23. NatureServe notes on phenology for Harbor Seal. NatureServe Explorer
  24. NatureServe notes on migration for Harbor Seal. NatureServe Explorer
  25. GBIF observation records of Harbor Seal in the US by month (chart on this page). GBIF
  26. NPSpecies park lists recording Harbor Seal as present (list on this page). NPS NPSpecies
  27. US states with the most GBIF observation records of Harbor Seal: Maine, California, Washington, Alaska, Oregon. Record counts follow observer effort, not population size. GBIF

Status, range and habitat come from NatureServe Explorer (CC BY 4.0) and USFWS ECOS at the snapshot date. Listings change by federal rule. State lists are where NatureServe records the species, not a promise that you will see it there. Never name a place smaller than a state. GBIF and park records count observations and checklists. They show where and when people report the species, not how many animals live there.

NatureServe. 2026. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org. (Accessed: October 30, 2026). Licensed under CC BY 4.0; SpeciesFacts selected and summarized it.