While as many as twenty species of shark are known to inhabit the western North Atlantic waters, little is known about their distribution, movements or occurrence. Even less is known about the threats they face.

Individual sharks (i.e. basking and white sharks) can be identified from photographs of their dorsal fins. This technique is called photo-identification and has been used to distinguish individuals of other species, such as humpback whales, right whales and sperm whales.

Commonly Encountered Shark Species

COSEWIC-CSofWSOf the many species that occur in our these waters, six are commonly sighted or encountered. Profiles of these species can be found below. Canadian species conservation status as assessed either by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and/ or listed under the Species at Risk Act (SARA) is indicated for each species.


DescriptionBasking Shark

Maximum Size: 10 m / 32 ft
Colour: Grayish-brown often with mottled appearance
Key Features:
1) Large conical snout
2) First dorsal fin is rounded on top, set further back on body and at a 45° degree angle
3) Five massive gill slits that almost encircle the head

May be confused with a White Shark.

Did you know?

• This gentle giant is the second largest fish in the world; second only to the whale shark.
• Despite their large size, basking sharks are filter feeders. They get their nutrition by filtering tiny zooplankton, small invertebrates and small fish as they move along the water with an open mouth.


DescriptionPorbeagle Shark

Maximum Size: 2.5 m / 12 ft
Colour: Heavy grey-blue
Key Features:
1) Distinctive white patch on the trailing edge of the first dorsal fin (see picture above)
2) Caudal fin has both primary and secondary keel
3) Teeth are smooth and tricuspid (a point on either side)

May be confused with a Shortfin Mako.

Did you know?

• Porbeagle sharks are a large warm-blooded shark that like to stay cool in Canadian waters.
• Their name is thought to arise from ‘porpoise’ referring to their shape, and ‘beagle’ referring to their hunting ability.


DescriptionBlue Shark

Maximum Size: 3.8 m / 13 ft
Colour: Deep Indigo blue
Key Features:
1) Long slender body with long pectorial fins.
2) Distinct countershading; dark blue colour on top, bright blue on the sides and white underneath
3) Nictitating membrane over its eye

Did you know?

• Blue sharks are the widest-ranging of all shark species and are known to travel distances over 9000 km.
• They are also the most common large shark seen in Canadian waters.


DescriptionWhite Shark

Maximum Size: 8 m / 26 ft
Colour: Lead grey, brownish grey or black
Key Features:
1) Large triangular-shaped first dorsal fin
2) Trailing edge of the first dorsal has unique markings or serrated edge
3) Large, triangular shaped teeth with serrated edge

May be confused with a Basking Shark.

Did you know?

• “Great” white sharks, the most famous and feared of all sharks, are the second largest fish found in Atlantic Canadian waters.
• As scientific research increases, their image as mindless killing machines is beginning to fade.


DescriptionShortfin Mako Shark

Maximum Size: 3.9 m / 13 ft
Colour: Metallic indigo blue
Key Features:
1) Distinct primary keel (secondary keel is absent)
2) Moderately short pectoral fins
3) Second dorsal is much smaller than the first dorsal; First dorsal is rounded in juveniles

May be confused with a Porbeagle Shark.

Did you know?

• Shortfin makos are the fastest of all shark species in the world, attaining speeds up to 74 kilometres an hour.
• Shortfin makos have been known to breach the surface, reaching heights of 20 feet.


Common Thresher Shark

Maximum Size: 6 m / 19 ft
Colour: Brown, gray, blue-gray or black
Key Features:
1) Extremely large upper lobe of the caudal fin (may be as long or longer than body length)
2) Short stubby snout
3) Second dorsal fin is much smaller than the first dorsal fin

Did you know?

• Thresher sharks are easily recognized by their large upper caudal fin, which can often be more than half of the total length of their body!
• With the help of their powerful tail, they can breach clear out of the water.

Species information above taken from Shark Identification Network. To report your shark sightings, visit SIN.