The basking shark, the second-largest fish globally, often sparks curiosity due to its immense size. This article clarifies their peaceful nature and addresses common misconceptions about their potential danger to humans.
Understanding Basking Sharks
Basking sharks are impressive in scale, with adults typically reaching lengths of 22 to 35 feet (6.7 to 10.7 meters) and weighing between 8,800 and 13,200 pounds (4,000 to 6,000 kg). Some individuals can grow up to 40 feet (12 meters) long and weigh up to 5 tons (4.5 metric tons). They are characterized by a large, conical snout and exceptionally long gill slits that almost encircle their head. These sharks are typically grayish-brown to almost black. Despite their imposing size, their biology and behavior distinguish them from predatory shark species.
Feeding Habits and Disposition
Basking sharks are filter feeders, straining tiny organisms from the water. They swim with their mouths open, sometimes up to 3 feet (1 meter) wide, to collect plankton and small crustaceans like copepods. Water flows through their mouth and over specialized, bristle-like gill rakers, which trap microscopic food while water exits through their gill slits. This passive ram feeding allows them to filter vast quantities of water, up to 2,000 tons per hour. Though they possess small, hooked teeth (only about 5-6 millimeters long) not used for hunting or biting, their diet and feeding mechanism underscore their docile disposition.
Recorded Interactions with People
Encounters between basking sharks and humans are overwhelmingly benign, with no confirmed records of intentional attacks. Despite their size, these sharks are not aggressive and pose no threat. Any rare incidents involving basking sharks are typically accidental, such as collisions with boats or entanglement in fishing gear. For example, a single isolated incident in 1937 involved a breaching basking shark that capsized a boat, leading to three drownings. Such occurrences are extremely rare, and the sharks’ behavior is an accidental consequence of their movements, which can include breaching.
Encountering Basking Sharks Safely
Observe basking sharks from a respectful distance. If in a boat, reducing speed to less than 5 knots and avoiding sudden course changes helps prevent accidental interactions. Boaters should avoid approaching a shark from directly in front or behind, instead moving parallel to its swimming direction. Swimmers and divers should maintain a distance of at least 13 feet (4 meters) from the shark and refrain from sudden movements. Never attempt to touch or harass a basking shark, as contact with their rough dermal denticle-covered skin can cause abrasions. Appreciating these animals from a distance ensures a safe experience for both observers and the sharks.