[social_warfare]
Meet the world’s most maligned sea creature, the white shark.
Carcharodon carcharias
White shark, great white shark, white pointer, white death, requin blanc (Fr.), grand requin blanc (Fr.)
Many people are surprised to learn that the white shark frequents the east coast of Canada, and even the St. Lawrence Gulf and Estuary. In fact, the white shark is observed more frequently in Atlantic Canada than in British Columbia.
The white shark is undoubtedly the best known and most feared shark in the world. And although its man-eater reputation is exaggerated, due in large part to sensationalistic movies and media reports, it is nonetheless a dangerous species that occasionally attacks people.
In the North Atlantic, the white shark is seasonally present in all of the Maritime provinces, Newfoundland and Labrador, and Québec. Over the last century, the majority of sightings and by-catch have occurred in the Bay of Fundy. However, captures and visual encounters have also been reported off Nova Scotia and throughout the entire Gulf of St. Lawrence. A white shark was even brought ashore as far inland as Rivière-Portneuf, which is well into the St. Lawrence Estuary and the province of Québec.
The ‘reappearance’ of the white shark in the St. Lawrence is more a return to some semblance of normalcy than a significant effect of climate change.
— Jeffrey Gallant, ORS
Surprising as this may be to some, the white shark is not a new visitor to any of these parts, nor is its long-established¹ presence in the St. Lawrence a direct result of climate change. Instead, the recent increase in sightings throughout the northwestern Atlantic more likely results from the protected status of both the white shark and its prey—seals—as well as the ubiquity of smartphones and social networks. We expect this trend to continue for as long as the white shark remains a protected species and humans take to sea.
¹ Vladykov, V. D., and R. A. McAlister. 1961. Preliminary list of marine fishes of Quebec. Le naturaliste canadien, 88(3): 17-113.
White shark (Carcharodon carcharias).
Illustration © Jeffrey Gallant | ORS
White shark (Carcharodon carcharias) filmed off Cape Cod (Massachusetts) by the Atlantic White Shark Conservancy in 2017.
Names and Taxonomy
Common Names: white shark, great white shark, white pointer, white death, requin blanc (Fr.), grand requin blanc (Fr.).
Order: Lamniformes (mackerel sharks)
Family: Lamnidae (mackerel sharks, porbeagles, white sharks)
Genus: Carcharodon
Species (scientific name): Carcharodon carcharias* (Linnaeus, 1758)
Carcharodon: from the Greek [karcharos] = to sharpen + [odous] = teeth
carcharias: Greek [karkharías] = shark
*sharp-toothed shark
Size and Appearance
Maximum length: up to 6.1 m¹
Mature length: (♂) 3.5-4 m, (♀) 4.5-5 m²
Weight: up to 1,970 kg³
The white shark is the third largest shark species and the largest carnivorous fish in the world. Many of the individuals that frequent the St. Lawrence are large, yet immature specimens. A white shark measuring 5.23 m (17.17 ft) was captured in the Gulf of St. Lawrence off Prince Edward Island in 1983. Its age was estimated at 17 years based on the growth bands in its vertebra, which means the shark would have grown to an even larger size had it reached maturity. Note: Although the Greenland shark rivals or surpasses the white shark in length, the white shark has up to twice the circumference and mass.
“Undoubtedly Carcharodon carcharias exceeds 6.1 m in length, but as yet there is no authenticated record of such a size.”
— Randall, 1987
The white shark’s colouration and colour distribution enables it to blend into its environment and to attack prey without being seen. Its physical appearance also leads to frequent cases of mistaken identity. Due to the similarity of its dorsal fin and overall size, the basking shark often passes for the white shark in the North Atlantic. Likewise, porbeagle sharks are frequently reported as juvenile white sharks in the St. Lawrence.
(Right) The white shark accidentally caught 20 km off Alberton (PEI) in 1983, is the largest specimen ever accurately measured in Canada, and one of the largest in the world. The remains of two harbour porpoise and several cod, which were probably first caught in the net, were found in the stomach of the shark.
¹ Refutation of lengths of 11.3, 9.0, and 6.4 m. attributed to the white shark, Carcharodon carcharias. California Fish and Game, 73 (3): 163–168, figs 1–3.
² Compagno, L., Dando, M., Fowler, S. 2005. Sharks of the World. Collins, 368 p.
³ Pregnant White Sharks and Full-Term Embryos from Japan. In: Klimley, A.P. & Ainley, D. (Eds.) Great White Sharks. The biology of Carcharodon carcharias: 139–155.
Dentition
The adult white shark’s teeth are large, triangular and serrated. Teeth in the lower jaw, and in juveniles, are slightly narrower. After a white shark has bitten into its prey, it shakes its head from side to side to saw off pieces of flesh.
In 2008¹, a team of scientists determined that the jaw power of a 3,324-kg white shark was 18,216 newtons (1,858 kgm/s²)².
Note: The white shark is not associated with the so-called ‘corkscrew’ wound which has been reported by the media. In fact, we do not believe that this specific wound pattern is caused by any shark species. See the Who is the Corkscrew Killer? for more details.
¹ Wroe, S., Huber, D. R., Lowry, M., McHenry, C., Moreno, K., Clausen, P., Ferrara, T. L., Cunningham, E., Dean, M. N., Summers, A. P. 2008. Three-dimensional computer analysis of white shark jaw mechanics: How hard can a great white bite? Journal of Zoology. 276 (4): 336–342.
² The kilogram-meter per second (kg·m/s or kg·m·s–1) is the standard unit of momentum . Reduced to base units in the International System of Units (SI), a kilogram-meter per second is the equivalent of a newton-second (N·s), which is the SI unit of impulse.
Distribution
The white shark has one of the widest ranges of any shark species. It is found from sub-Arctic to tropical conditions. In the Atlantic Ocean, the distribution of the white shark extends from the island of Newfoundland to Florida. It has been documented as far west as Rivière-Portneuf¹ in the St. Lawrence Estuary, which is less than four hours from Quebec City. The white shark routinely² ventures into shallow water along the shoreline in search of marine mammals such as seals, which brings it in close proximity to locations where people engage in water activities.
Variations in the seasonal migrations of prey species, an increase in seal numbers, and the prevalence of boaters and fishers equipped with smartphones may partly explain the apparent increase in white shark observations in the St. Lawrence. The greater concentration of white sharks along the East Coast may also result in more individuals entering the Gulf of St. Lawrence as they spread out to avoid conflict, and thus re-establish the species throughout its former range.
Until recently, the white shark traditionally appeared in the St. Lawrence for a brief period from mid- to late-summer, but its seasonal excursions into the warming gulf and estuary now occur from at least July to October.
¹ Vladykov, V. D., and R. A. McAlister. 1961. Preliminary list of marine fishes of Quebec. Le naturaliste canadien, 88(3): 17-113.
² Winton Megan V., Sulikowski James, Skomal Gregory B. 2021. Fine-scale vertical habitat use of white sharks at an emerging aggregation site and implications for public safety. Wildlife Research, https://doi.org/10.1071/WR20029.
Provisional distribution of the white shark (Carcharodon carcharias) based on research by the St. Lawrence Shark Observatory (ORS). This map is updated with new and historical data on an ongoing basis. To submit additional sightings or captures, please contact us. Click on shark icons for observation details. Note: Map works best in full-screen mode.
[webmap id=3388]
Prey
The white shark is an opportunistic predator that will eat just about anything that comes across its path, either dead or alive.
Verified stomach contents
Fish: (partial list) Atlantic salmon, hake, halibut, mackerel, tuna, other sharks and skates.
Mammals: pinnipeds (seals), porpoises, dolphins, large cetaceans (usually dead).
Others: birds, sea turtles.
Predators
The only confirmed predator of the white shark is the orca (Orcinus orca), which has repeatedly been observed hunting and killing¹ white sharks at various locations. Although the orca is historically² known to frequent the St. Lawrence Gulf and Estuary, its presence in recent³ years has been scarce and sporadic, and mostly limited to the upper portion of the gulf. Since the white shark is equally rare, and because most chance encounters would take place at the northern limit of the shark’s range, occurrences of predation by orcas in the St. Lawrence are likely very rare or non-existant.
¹ Jorgensen, Salvador & Anderson, Scot & Ferretti, Francesco & Tietz, James & Chapple, Taylor & Kanive, Paul & Bradley, Russell & Moxley, Jerry & Block, Barbara. 2019. Killer whales redistribute white shark foraging pressure on seals. Scientific Reports. 9. 10.1038/s41598-019-39356-2.
² Vladykov, V.D. 1944. Études sur les mammifères aquatiques III. Chasse, biologie et valeur économique du marsouin blanc ou beluga (Delphinapterus leucas) du fleuve et du golfe St Laurent. Dept. Pêcheries Prov. Québec. 194 pp.
³ Wenzel, Frederick & Sears, R. 1988. A note on killer whales in the Gulf of St. Lawrence, including an account of an attack on a minke whale. Rit Fiskideild. 11. 202-204.
(Above) Orcas chasing a white shark in South Africa.
Reproduction
Little is known about the white shark’s reproduction. It is ovoviviparous and reaches sexual maturity at around 30 years (26 yrs for males and 36 yrs for females)¹. Although birth has never been observed, gestation is believed to last around 12 months. Females give birth to 4 to 14 pups measuring approximately 135-151 cm at birth².
¹ Natanson Lisa J., Skomal Gregory B. (2015) Age and growth of the white shark, Carcharodon carcharias, in the western North Atlantic Ocean. Marine and Freshwater Research 66, 387-398.
² Castro, J. I. 2011. The Sharks of North America. Oxford University Press, 613.
Life Expectancy
A study¹ published in 2014 demonstrated that white sharks grow more slowly and live longer than previously thought. Age and growth estimates for the northwestern Atlantic population were derived from vertebral band counts and radiocarbon dating on the vertebrae of eight specimens (four males and four females). Age estimates were up to 40 years for the largest female (526 cm) and 73 years for the largest male (493 cm). Although this would make the white shark one of the longest-lived chondrichthyan fishes (sharks, skates, rays, and chimaeras), it is still nowhere near the lifespan of the venerable Greenland shark.
¹ Li Ling Hamady, Lisa J. Natanson, Gregory B. Skomal, Simon R. Thorrold. Vertebral Bomb Radiocarbon Suggests Extreme Longevity in White Sharks. PLoS ONE, 2014; 9 (1): e84006
² Nielsen, J., Hedeholm, R. B., Heinemeier, J., Bushnell, P. G., Christiansen, J. S., 2815 Olsen, J., et al. (2016). Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus). Science 353, 702–704.
Attacks
Although injuries and deaths have occurred along the U.S. Eastern Seaboard, including a recent fatal encounter in the state of Maine (July 2020), no such direct attacks on humans have been attributed to the white shark in Eastern Canada. As of 2021, only a handful of confrontations involving small fishing boats have been reported in the Maritimes and Newfoundland over the last century. In one incident, a man died from drowning after a white shark attacked his dory off Cape Breton in 1953. Unfortunately, it may only be a question of time before increasing numbers of white sharks and humans sharing nearshore waters, along with a combination of adverse physical variables such as poor visibility and the proximity of regular prey species, i.e. being in the wrong place at the wrong time, lead to one or more white shark incidents in Atlantic Canada and Québec.
Fisheries
None. Although there is no directed fishery for the white shark in Canada, several individuals have nonetheless been caught as by-catch since record keeping began in the 19th century.
Status
The white shark is listed as an endangered species by COSEWIC (Committee on the Status of Endangered Wildlife in Canada).
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