The Common Thresher Shark, known as the Atlantic thresher, is found in temperate and tropical waters worldwide. It is the largest species of thresher shark, reaching lengths up to 6.1 meters and weighing up to 700 kilograms. While enjoying our weekly run on the beach, we were amazed to discover this vulnerable species of thresher shark (Common Thresher Shark) washed ashore.
It is characterised by its large, scythe-like tail which it uses to whip prey and stun them. It feeds primarily on schooling fishes, squids, and cuttlefish. The Common Thresher Shark is a vulnerable species due to its slow growth rate, late maturity, and the fact that it is often caught as a bycatch in fisheries.
On 7 March 2023, a juvenile thresher shark was discovered dead on the beach in Sunset Beach, Cape Town. The shark was first spotted while we were running on the beach. Upon closer inspection, it was determined that the shark was dead and had been washed ashore.
The cause of death is unknown, but it could be due to human and natural causes. It is possible that the shark could have been caught accidentally in a fishing net or struck by a boat, leading to its death. It is also possible that the shark could have died due to natural causes, such as disease or being attacked by hunting sea mammals.
“It is characterised by its large, scythe-like tail which it uses to whip prey and stun them.”
Facts about the Thresher Shark
The death of the Common Thresher Shark in Sunset Beach, Cape Town, will significantly impact the local ecosystem. It plays a vital role in controlling the populations of its prey species. Without this predator, the populations of its prey will increase, leading to a disruption of the food web.
There are three species of Common Thresher Sharks: the Common Thresher Shark (Alopias vulpinus), the bigeye thresher shark (Alopias superciliosus), and the pelagic thresher shark (Alopias pelagicus).
This juvenile Common Thresher Shark is the largest of the three species, reaching lengths up to 6.1 meters and weighing up to 700 kilograms. The bigeye thresher shark is smaller, reaching lengths of up to 4.9 meters and the pelagic thresher shark is the smallest, reaching lengths of up to 3.4 meters. All three species of Common Thresher Sharks are found in temperate and tropical waters worldwide.
Thresher sharks are considered vulnerable due to their slow growth rate, late maturity, and the fact that they are often caught as bycatch in the over-exposed and arguably unregulated fishing industry. Additionally, they are targeted by commercial fishing operations for their meat, fins, and liver oil. These factors have led to a decline in thresher shark populations worldwide, making them vulnerable to extinction.
The last time this species was found on the Southern Tip of Africa was in 2018, when a thresher shark was washed up on Muizenberg beach in Cape Town. But also in 2019, a juvenile thresher shark was found in the False Bay’s Yacht Club, a small coastal harbour town in South Africa.
The death of the Common Thresher Shark in Sunset Beach, Cape Town, is concerning and highlights the need to better protect this vulnerable species. We must take action to ensure that this species is not lost forever. We must work to reduce our impact on the marine environment by limiting fishing activities, reducing plastic pollution, and educating ourselves and others about the importance of protecting thresher sharks and other marine species. Together, we can ensure the Common Thresher Shark’s future, and the marine ecosystem’s balance.
All three thresher shark species have been listed as vulnerable to extinction by the World Conservation Union.
Comment
[…] Thresher sharks are large lamniform sharks of the family Alopiidae found in all temperate and tropical oceans of the world; the family contains three extant species, all within the genus Alopias. All three thresher shark species have been listed as vulnerable to extinction by the World Conservation Union. Read on […]