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Canada: Several great white sharks have mysteriously lost their lives
by Yohan Demeure
February 13, 2025, 3:45 p.m.
Recently, several great white sharks were found dead on the Canadian coast. However, they had a strange anomaly in their brains. While the scientific community is closely monitoring the phenomenon, it remains quite difficult to explain for the moment.
Five animals died in similar conditions
Present in all four corners of the world, the great white shark ( Carcharodon carcharias ) can measure up to six meters long. It is therefore one of the largest fish existing on Earth. Sometimes associated with attacks on humans, the animal is nevertheless classified as vulnerable by the International Union for Conservation of Nature (IUCN). In recent months, the Atlantic coast of Canada has been the scene of macabre discoveries. Several sharks of this species have been found dead and some of them had a brain abnormality , as explained by the New York Times in an article on February 2, 2025.
The first of these predators washed up on Prince Edward Island, the country's smallest province. The animal, which was 2.65 m long and weighed 227 kg, underwent an autopsy. According to the results, the shark had no significant physical injuries and its internal organs appeared intact. Until recently, the animal's death remained a mystery. Researchers then conducted microscopic analyses and discovered the cause of death: meningoencephalitis. This disease involves inflammation of the brain tissue that causes compression and swelling of the brain. According to Canadian researchers, this pathology can prevent the animal from feeding and maintaining its own balance until it dies.
A disease affecting sharks that is still unexplained
Megan Jones, a veterinary pathologist at the College and regional director of the Canadian Wildlife Health Cooperative (CWHC), is the expert who performed the necropsy. She quickly became concerned after other similar cases appeared across the country. In total, four other stranded sharks appeared to have the same characteristics as the first. Researchers now need to learn more about the pathology and especially its origin. In addition, they will have to try to understand if this is a mass epidemic affecting great white sharks. While research is currently ongoing, some obstacles remain. Some of the bodies have remained in the water too long and are too degraded to be finely analyzed .
Two of the bodies, however, could have signaled a potential spread of the disease . The first contained large pieces of porpoise in its stomach, a prey possibly infected with parasites or bacteria. The second, found in a port, lay dying for days, swimming disoriented. However, autopsies did not reveal any signs that could suggest meningoencephalitis.
Finally, the next step will be under the responsibility of the Washington Animal Disease Diagnostic Lab (WADDL), to whom the Canadian researchers sent the sharks' brain tissue. This laboratory will perform genetic sequencing of the samples in order to determine precisely whether it is a question of infection by a virus, bacteria or parasite.
https://sciencepost.fr/canada-grands-requins-blancs-mort-mysterieuse/
Canada: Several great white sharks have mysteriously lost their lives
by Yohan Demeure
February 13, 2025, 3:45 p.m.
Recently, several great white sharks were found dead on the Canadian coast. However, they had a strange anomaly in their brains. While the scientific community is closely monitoring the phenomenon, it remains quite difficult to explain for the moment.
Five animals died in similar conditions
Present in all four corners of the world, the great white shark ( Carcharodon carcharias ) can measure up to six meters long. It is therefore one of the largest fish existing on Earth. Sometimes associated with attacks on humans, the animal is nevertheless classified as vulnerable by the International Union for Conservation of Nature (IUCN). In recent months, the Atlantic coast of Canada has been the scene of macabre discoveries. Several sharks of this species have been found dead and some of them had a brain abnormality , as explained by the New York Times in an article on February 2, 2025.
The first of these predators washed up on Prince Edward Island, the country's smallest province. The animal, which was 2.65 m long and weighed 227 kg, underwent an autopsy. According to the results, the shark had no significant physical injuries and its internal organs appeared intact. Until recently, the animal's death remained a mystery. Researchers then conducted microscopic analyses and discovered the cause of death: meningoencephalitis. This disease involves inflammation of the brain tissue that causes compression and swelling of the brain. According to Canadian researchers, this pathology can prevent the animal from feeding and maintaining its own balance until it dies.
A disease affecting sharks that is still unexplained
Megan Jones, a veterinary pathologist at the College and regional director of the Canadian Wildlife Health Cooperative (CWHC), is the expert who performed the necropsy. She quickly became concerned after other similar cases appeared across the country. In total, four other stranded sharks appeared to have the same characteristics as the first. Researchers now need to learn more about the pathology and especially its origin. In addition, they will have to try to understand if this is a mass epidemic affecting great white sharks. While research is currently ongoing, some obstacles remain. Some of the bodies have remained in the water too long and are too degraded to be finely analyzed .
Two of the bodies, however, could have signaled a potential spread of the disease . The first contained large pieces of porpoise in its stomach, a prey possibly infected with parasites or bacteria. The second, found in a port, lay dying for days, swimming disoriented. However, autopsies did not reveal any signs that could suggest meningoencephalitis.
Finally, the next step will be under the responsibility of the Washington Animal Disease Diagnostic Lab (WADDL), to whom the Canadian researchers sent the sharks' brain tissue. This laboratory will perform genetic sequencing of the samples in order to determine precisely whether it is a question of infection by a virus, bacteria or parasite.
https://sciencepost.fr/canada-grands-requins-blancs-mort-mysterieuse/