Basking sharks, the second-largest fish in the ocean, can reach impressive lengths, often exceeding 26 feet and sometimes over 33 feet. Their immense size naturally raises questions about their potential danger to humans. Despite their imposing appearance, these marine giants possess characteristics that distinguish them from predatory sharks. Understanding their biology and behavior helps clarify why they are not considered a threat to people.
What Are Basking Sharks Like?
Basking sharks are massive marine animals, typically averaging 22 to 29 feet in length and weighing several tons. While their size might seem intimidating, it does not indicate aggression towards humans. These sharks are filter feeders, consuming zooplankton. They capture this tiny prey by swimming with their cavernous mouths wide open, filtering vast quantities of seawater through their gill rakers. A 16-foot basking shark can filter up to 500 short tons of water per hour.
Their feeding mechanism involves specialized gill rakers, which are bristle-like structures that trap plankton as water passes over their gills. Unlike predatory sharks, basking sharks possess numerous, very small teeth, typically only 5-6 millimeters long, which are curved backward and are not used for biting or tearing prey. These small, hooked teeth primarily function as a sieve, preventing food particles from escaping, rather than for active predation. Basking sharks are generally slow-moving and placid, often seen swimming near the surface. They can be solitary or found in small groups, and are not known to be territorial or aggressive.
Do They Pose a Threat to Humans?
Basking sharks are harmless to humans. There are no documented cases of basking sharks attacking or consuming people. Their diet consists solely of zooplankton, which means humans are not a part of their natural prey. Even with their large mouths, which can open up to 3 feet wide, their throats are much smaller, making it impossible for them to swallow a human.
Any rare negative interactions with basking sharks are typically unintentional and not predatory. Due to their large size and habit of swimming near the surface, accidental collisions with boats can occur. There is one historical report from 1937 of a breaching basking shark capsizing a boat, which resulted in fatalities, but this remains an extremely isolated incident. Such occurrences are related to the shark’s physical presence and movement, not aggressive intent.
When encountering basking sharks, maintaining a respectful distance is recommended. Swimmers and divers should keep at least 4 meters away from the shark and be mindful of its powerful tail. Boaters are advised to reduce speed to below 5 knots when sharks are sighted and avoid sudden movements, switching engines to neutral if within 10 meters to prevent injury to the shark. These guidelines prioritize the safety of both humans and the protected basking sharks, which are sensitive to disturbance.