Connecticut mammals

Harbor Seal in Connecticut

Phoca vitulina

Native to Connecticut

Not listed as nonindigenous in Connecticut by USGS NAS; native to its Connecticut range.

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

LC – Least Concern

Widespread and abundant; not at risk.

Common seal (Phoca vitulina) 2Harbor seal (Phoca vitulina) at Magdalen fjord, Svalbard (2)Common seal (Phoca vitulina)Harbor seal (Phoca vitulina) at Magdalen fjord, Svalbard (1)SeehundHarbor Seal (Phoca vitulina)
Photo: Charles J. Sharp · CC BY-SA 4.0Common seal (Phoca vitulina) 2Photo: AWeith · CC BY-SA 4.0Harbor seal (Phoca vitulina) at Magdalen fjord, Svalbard (2)Photo: Charles J. Sharp · CC BY-SA 4.0Common seal (Phoca vitulina)Photo: AWeith · CC BY-SA 4.0Harbor seal (Phoca vitulina) at Magdalen fjord, Svalbard (1)Photo: Marcel Burkhard · CC BY-SA 2.0 deSeehundPhoto: Andrea · CC BY 4.0Harbor Seal (Phoca vitulina)

Harbor Seal in Connecticut, by the numbers

Occasional in Connecticut 25th most recorded of 70 mammals logged in Connecticut

90 occurrence records
86 with iNaturalist photos
Apr 24, 2026 Last seen in Connecticut

Records from 2000–2026.

90 total records count every Connecticut occurrence from GBIF and iNaturalist; the monthly chart covers the 87 records with a full observation date.

When to look for the Harbor Seal in Connecticut

Most sightings fall in December to March.

87 Connecticut occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly Connecticut records (table)
MonthRecords
January23
February17
March15
April12
May0
June0
July0
August0
September0
October1
November3
December16

Monthly harbor seal occurrence records (iNaturalist and GBIF) in Connecticut, 2000–2026.

Seasonality

Year-round in Connecticut, with recorded sightings peaking in December–March.

Occurrence map

Where Harbor Seal has been recorded in Connecticut

90 records mapped · zoom and drag to explore

90 Connecticut records mapped

Where it's recorded in Connecticut

CountyRecords
New Haven County 22
New London County 6
Fairfield County 4
Middlesex County 1
Other localities 57

The complete county distribution, spread across 4 Connecticut counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Harbor seals are winter visitors to Connecticut’s Long Island Sound rather than year-round coastal residents in the usual sense. From Hammonasset, Bluff Point, and the outer waters near Barn Island, scan exposed rocks, ledges, and quiet water with binoculars. Their rounded head and spotted gray coat can be subtle at a distance.

Records concentrate from December through April, matching the cold-water season. A seal resting ashore is not automatically stranded: remain far away, keep dogs leashed, and contact an authorized marine-mammal responder if it is injured, entangled, or repeatedly disturbed.

Occurrence data from iNaturalist and GBIF.

Common seal (Phoca vitulina) 2
Full species profile Harbor Seal Phoca vitulina Size 1.4–1.9 m4.6–6.2 ft Weight 55–170 kg121.3–374.8 lb Lifespan Up to 47.6 yr View the full profile

More mammals in Connecticut in the atlas

Data & sources

The data and visualizations on this page draw on these open sources:

  • GBIFCC-BY 4.0occurrence records behind the range map, elevation, and record counts
  • iNaturalistCC0 / CC-BY / CC-BY-SAobservations, photos, and audio recordings
  • NatureServe ExplorerCC-BYthe state conservation rank
  • IUCN Red Listattributed factthe global conservation status
  • USGS NASpublic domainnative / introduced status
  • Natural Earthpublic domainthe relief basemap