by Zachary Tay
Also known as Atlantic threshers, common thresher sharks are easily distinguished by their extra long upper tail fin. They can reach 20 feet and their tail makes up around half of their length. Common threshers are migratory and live in many seas around the world. They favor the Pacific and Indian Oceans, especially at the continental shelves of America and Asia. But the exact habitat, again, remains largely a mystery. Thresher Sharks love open and deep waters, they are also found in shallow waters near coastal areas. They are generally not found deeper than 500 meters (1,640ft).
They regularly move to higher latitude areas to head into warmer water. Common thresher sharks are strong, fast swimmers and eat mainly bony fish. They use their long tail to strike and incapacitate their prey. Common threshers are caught by commercial fishers as they are highly sought after for their meat. They are also a valued prize by sport fishers due to their power and the fight that they put up. Common thresher sharks are a vulnerable species due to fishing pressure on populations.
Silky, bigeye thresher, common thresher, and pelagic thresher sharks are in particular danger. Overfishing in targeted shark fisheries, by-catch in fishing gear targeting other species, and high levels of illegal and unregulated fishing have caused drastic reductions in their populations wherever they are found. International protection measures are piecemeal at best. Management measures need to catch up to the scale of the problems facing these sharks before it is too late.
Unfortunately, no international measures are in place specific to common thresher sharks. However, as a result of increasing concern about the plight of thresher sharks, Sri Lanka has proposed that the common thresher sharks be added to Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which would greatly restrict global trade in thresher shark products – limiting it to fisheries where harvesting is sustainable. This is appropriate as the large fins of thresher sharks are typically exported to Asian countries with a taste for shark fin soup, where they fetch a high price.
