Basking sharks, the second-largest fish in the world, are immense marine giants, reaching over 30 feet and weighing several tons. Despite their imposing appearance, a common misconception exists regarding their potential aggression towards humans. Understanding their true nature reveals a remarkably different picture.
Understanding Basking Shark Behavior
Basking sharks are not aggressive towards humans. They are considered docile and gentle giants, posing virtually no threat. There are no documented cases of basking sharks intentionally attacking, biting, or even bumping humans. Encounters with these sharks are generally passive, with the animals showing little interest in human presence.
While rare incidents have occurred, such as a boat capsizing in 1937 after a breaching basking shark accidentally landed on it, these are isolated accidents, not intentional aggression. The rough texture of their skin, covered in dermal denticles, could cause abrasions if contact were made, but this would be an unintentional outcome. Basking sharks are typically tolerant of divers and boats, often allowing close observation without exhibiting any signs of hostility.
Diet and Lifestyle
The non-aggressive nature of basking sharks stems from their unique diet and feeding strategy. Unlike predatory sharks, basking sharks are filter feeders, consuming microscopic organisms. Their primary food source consists of zooplankton, particularly small crustaceans called copepods, which they filter from the water.
Basking sharks employ a passive feeding method known as ram feeding, swimming slowly with their enormous mouths wide open. Their mouths can open up to three feet wide, allowing vast quantities of water to pass through. Specialized gill rakers, comb-like structures lining their gill slits, efficiently strain plankton from the water.
An adult basking shark can filter 2,000 tons of seawater per hour. This specialized diet means they possess numerous, very small teeth, unsuitable for grasping or tearing large prey, further reinforcing their harmless disposition towards humans.
Safe Encounters
Interacting with basking sharks in the wild requires respect for their space and adherence to safety guidelines. When observing these animals from a vessel, maintain a distance of at least 100 meters. If a basking shark is sighted within 10 to 50 meters, vessel operators should reduce speed to below 6 knots or switch the engine to neutral to avoid accidental collisions. Approaching them from the side, parallel to their direction of movement, is advisable, rather than from the front or behind.
For swimmers and divers, a minimum distance of 4 meters from any shark should be maintained. Never attempt to touch, chase, or feed a basking shark, as this can disturb their natural behavior. If a shark approaches, remaining calm and still is the best course of action.
While generally docile, their large size means an accidental tail strike could cause injury, so awareness of their movements is always prudent. Reporting sightings to relevant marine authorities can also contribute to conservation efforts.