The blue shark (Prionace glauca) is a highly pelagic species and one of the most wide-ranging sharks in the world, inhabiting temperate and tropical oceans across the globe. In the North Atlantic, blue sharks undertake vast seasonal migrations in a broad circular pattern linking Africa, North America, and Europe. Individuals typically arrive in Atlantic Canadian waters during the spring and depart in the fall.

Built for life in the open ocean, the blue shark is recognised by its slender body, extremely long pectoral fins, and deep blue coloration. It feeds primarily on squid and schooling fish and is capable of travelling thousands of kilometres across the Atlantic.

A number of blue sharks seasonally enter the Gulf of St. Lawrence, where they have been documented[1] as far inland as the mouth of the Estuary off the Gaspé Peninsula.

(1) Gallant, J., unpublished data.

The blue shark seasonally enters the Gulf of St. Lawrence and occasionally reaches the mouth of the Estuary off the Gaspé Peninsula. Most observations occur during the warmer months, when the species follows concentrations of squid and pelagic fish into Canadian waters as part of its vast North Atlantic migration.

According to the Canadian Shark Attack Registry, there are no confirmed incidents involving blue sharks (Prionace glauca) and humans in Canadian waters. Although the species is a large and active pelagic predator, it primarily feeds on squid and schooling fish and rarely comes into contact with people in Atlantic Canada.

Elsewhere in the world, blue sharks have occasionally been involved in incidents involving fishers, shipwreck survivors, or baited situations at sea. The species is known to become bold and highly competitive in the presence of bait or struggling prey, particularly when multiple individuals are feeding together. Recreational divers and shark-tour operators have sometimes described inquisitive or persistent behaviour around baited vessels.

Despite this reputation, interactions with humans remain uncommon in Canadian waters and are not considered a significant public-safety concern under normal circumstances.

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

The blue shark is frequently caught as by-catch in offshore pelagic fisheries targeting tuna and swordfish in Atlantic Canada, although directed commercial fisheries for the species are limited. Recreational catch-and-release shark fishing also occurs in some parts of Atlantic Canada, particularly in Nova Scotia, where shark derbies and tournaments historically targeted blue sharks and other pelagic species. In recent years, however, several longstanding derbies have been discontinued following increased conservation concerns and regulatory changes.

Despite its wide distribution and apparent abundance, the blue shark remains vulnerable to overexploitation because of its relatively slow growth, late maturity, and high mortality associated with international longline fisheries and the global shark fin trade.

The blue shark (Prionace glauca) is currently listed as Not at Risk by COSEWIC (Committee on the Status of Endangered Wildlife in Canada) for the North Atlantic population. The species was previously designated Special Concern in 2006 because of concerns related to by-catch and international fishing pressure, but was reassessed in 2016 after Canadian data suggested stable or slightly increasing catch rates and improved fisheries management measures. The species is not listed under Canada’s Species at Risk Act (SARA).

Globally, the blue shark is classified as Near Threatened by the International Union for Conservation of Nature (IUCN). It is one of the most heavily fished sharks in the world and is frequently captured both intentionally and as by-catch in tuna and swordfish fisheries. Tens of millions of blue sharks are estimated to be killed annually for the international meat and shark fin trades.

In Atlantic Canada, blue sharks are commonly encountered by offshore pelagic fisheries and are occasionally sought by recreational shark anglers. Because of its highly migratory nature, effective conservation of the species depends largely on international fisheries management and cooperation between Atlantic nations.