Grey Seal (Halichoerus grypus)

Status: needs expert review. Conservation claims cite the IUCN Red List and NOAA Fisheries; a reviewer should confirm currency and regional-stock detail before approval. The grey seal (Halichoerus grypus) is a large "true seal" (phocid) of North Atlantic coasts, recognizable by its long, horse-like muzzle.

At a glance

Field	Value	Source
Scientific name	Halichoerus grypus	WoRMS / authority
Guild	pinniped (phocid / true seal)	—
IUCN status	Least Concern (global, assessed 2016)	IUCN Red List
Population trend	Increasing (global)	IUCN Red List
Western N. Atlantic abundance	Roughly 450,000 in Canadian and U.S. waters combined; stable to increasing	NOAA Fisheries
Range	Coastal North Atlantic — eastern Canada/northeastern U.S. and northwestern Europe	NOAA Fisheries

Identification

A large phocid with a long, broad muzzle and a relatively flat profile — the genus name Halichoerus ("hook-nosed sea pig") points to the distinctive snout. Adult males are darker and noticeably larger than females, with heavy necks and scarring; females are paler with dark blotches on a lighter background. Like other true seals, grey seals lack external ear flaps and move on land by undulating rather than walking on rotated hind flippers. They are easily confused with harbor seals where ranges overlap; the longer straight muzzle and parallel-set nostrils help separate them.

Ecology and behavior

Grey seals haul out on rocky shores, sandbars, ledges, and islands to rest, molt, and breed, and forage on a range of fish and invertebrates in coastal and shelf waters. In the western North Atlantic, breeding colonies form at sites such as Sable Island and the Gulf of St. Lawrence (NOAA Fisheries). Pupping and molting are sensitive periods when disturbance carries the highest cost. Behavioral specifics should be cited to published research and confirmed in review.

Conservation status and threats

The grey seal is assessed Least Concern by the IUCN (2016), with an increasing global trend (IUCN Red List). In the western North Atlantic, NOAA reports roughly 450,000 animals across Canadian and U.S. waters and a stable-to-increasing trajectory (NOAA Fisheries). A healthy global status does not mean no pressure: NOAA lists entanglement in fishing gear (gillnets, trawls, weirs), vessel and vehicle strikes, chemical contaminants accumulating in blubber, oil-spill and energy-development impacts, and harassment and illegal killing as ongoing threats (NOAA Fisheries). Report figures as the cited authorities state them; a reviewer should confirm regional-stock specifics.

How to observe responsibly

NOAA's marine life viewing guidelines call for keeping at least 50 yards (about 45 m) from seals and limiting observation to 30 minutes or less (NOAA Fisheries). Hauled-out seals — especially mothers and pups during the breeding season — must not be approached, surrounded, or made to flush into the water; a disturbed female can separate from or abandon a pup. Keep dogs leashed near haul-outs and follow the strictest local rule where regulations differ (ETHICS.md). This page keeps haul-out and pupping sites to regional granularity.

How you can help

• Log sightings to a recognized citizen-science platform without approaching haul-outs (see the iNaturalist dataset card).
• Report stranded or entangled seals to the local marine-mammal stranding network rather than intervening yourself.
• Support coastal haul-out protection and disturbance-reduction programs, and choose operators that keep their distance.