The porbeagle is a coastal and pelagic shark species found in the cold-temperate waters of the North Atlantic, as well as in the southern hemisphere. Like other members of the family Lamnidae, it is endothermic (warm-blooded), allowing it to maintain high activity levels in the cold waters of Atlantic Canada and the St. Lawrence.

The porbeagle is a member of the mackerel sharks, which includes the white shark, the shortfin mako, and the extinct megalodon. These sharks share the same general shape, which oftens leads to misidentification, especially when observed from a boat.

Contrary to recent news headlines associating the porbeagle’s presence with global warming, this shark has long been a regular visitor to the St. Lawrence Gulf and Estuary where it is frequently mistaken for the white shark or shortfin mako. All mackerel sharks are very fast swimmers capable of lightening bursts of speed[1]. The porbeagle’s closest relative is its North Pacific cousin, the salmon shark (Lamna ditropis).

(1) Jensen, C., L. Natanson, H.L. Pratt Jr, N.E. Kohler, and S.E. Campana. 2002. The reproductive biology of the porbeagle shark (Lamna nasus) in the western North Atlantic Ocean. Fishery Bulletin 100(4):727-738.

• Average length of 1.5 to 2.5 metres in Atlantic Canada and Québec, although larger individuals occasionally occur.
• Dark blue-grey to slate-grey above with a sharply contrasting white underside.
• Streamlined yet powerfully built body with a pointed conical snout and large black eyes adapted for cold-water hunting.
• Distinctive white patch at the rear base of the first dorsal fin, a key identification feature.
• Pectoral fins marked by dark trailing edges and black tips on the underside.
• Second dorsal fin much smaller than the first.
• Narrow blade-like teeth equipped with small lateral cusplets on each side.
• Crescent-shaped tail with upper and lower lobes nearly equal in size, reflecting its exceptional swimming speed.
• Fast-swimming predator that actively hunts schooling fish such as mackerel and herring.
• Seasonal presence in Atlantic Canada and Québec, including the Gulf and Estuary of the St. Lawrence.

The porbeagle shark is found throughout the Gulf of St. Lawrence and regularly enters the Estuary as far upstream as La Malbaie, roughly 140 km downstream from Québec City. The northernmost confirmed observation in Atlantic Canada was reported from Nain, Labrador. In the St. Lawrence, porbeagles typically arrive in late spring or early summer and have largely departed by November.

The timing and duration of this seasonal migration may be influenced by changing oceanographic conditions associated with climate change, particularly shifts in water temperature and prey distribution.

According to the Canadian Shark Attack Registry, the porbeagle shark has been implicated in one confirmed incident involving a human in Canada, as well as one borderline case in Maine. In both situations, the shark may initially have been attracted to the area by scent trails associated with fresh bait or other attractants linked to human activity.

The porbeagle is primarily a predator of fish such as mackerel and herring. As a result, interactions with humans are considered extremely rare and may involve investigative, territorial, or overstimulated behaviour in the presence of bait, struggling fish, or concentrated attractants.

(1) Gallant, J. (2022. July 26). Canadian Shark Attack Registry (1st ed.). St. Lawrence Shark Observatory.

None. The directed commercial fishery for the porbeagle shark in Atlantic Canada was closed in 2013 following major population declines linked to decades of overfishing. Although no targeted fishery currently exists in Canada, porbeagle sharks are still occasionally caught as by-catch in other fisheries. Recovery of the northwestern Atlantic population is expected to be slow because of the species’ late maturity and low reproductive rate.

The porbeagle shark (Lamna nasus) is listed as Endangered by COSEWIC (Committee on the Status of Endangered Wildlife in Canada) because of severe historical population declines associated with overfishing in the northwestern Atlantic. The species is also listed under Canada’s Species at Risk Act (SARA), which provides legal protection and requires recovery planning.

Globally, the porbeagle shark is classified as Vulnerable by the International Union for Conservation of Nature (IUCN). The species has experienced substantial declines in several parts of its range because of targeted commercial fisheries and by-catch. Recovery is expected to be slow due to the porbeagle’s late maturity, long lifespan, and low reproductive rate.

In Atlantic Canada, the directed commercial fishery for porbeagle sharks was closed in 2013 following major stock declines. Although the northwestern Atlantic population has shown signs of partial recovery in recent years, the species remains vulnerable to fishing pressure and accidental capture.