Sharks do not “like” humans, nor are people part of their natural diet. Their behavior is driven by instinct and survival needs, not a preference for human flesh. Sharks evolved millions of years before humans existed, meaning people were never a part of their normal diets.
Shark Sensory World and Preferred Prey
Sharks possess highly developed sensory systems designed to locate their natural prey. Their sense of smell is acute, capable of detecting minute traces of blood and other chemical cues. Sharks primarily feed on fish, squid, and crustaceans. Larger species like great whites and tiger sharks also prey on marine mammals such as seals, sea lions, and small whales.
Beyond smell, sharks utilize a lateral line system that detects vibrations and pressure changes in the water. This system helps them pinpoint prey, especially in low visibility. Additionally, sharks have specialized electroreceptors called Ampullae of Lorenzini, concentrated on their snouts. These pores detect the faint electrical fields generated by muscle contractions, allowing sharks to find hidden prey.
Understanding Shark Encounters
Interactions between sharks and humans are typically not predatory attempts to consume people. One common explanation is mistaken identity, where a shark might confuse a swimmer or surfer for its natural prey. From below, a person on a surfboard can resemble a seal or sea lion, particularly in murky waters. Sharks rely on vision for targeting prey and may not differentiate humans from pinnipeds.
Another reason for human encounters is curiosity. Sharks often investigate unfamiliar objects using their mouths, which can lead to an exploratory “test bite.” This allows them to gather sensory information. Such bites are often not sustained, indicating an investigation rather than a feeding attempt. Sharks may also bite defensively if they feel threatened, surprised, or cornered.
The Rarity of Predatory Attacks
Predatory shark attacks on humans are exceedingly rare events. Globally, fewer than 100 unprovoked shark bites are reported each year, a low number considering the vast amount of time people spend in the ocean. The likelihood of a fatal shark attack is very small compared to other common risks.
Most interactions are investigatory or defensive, with sharks often releasing a human after a single bite. This behavior suggests that humans are not a preferred food source. If humans were a primary prey, the number of attacks and fatalities would be significantly higher. The extreme rarity of attacks underscores that humans are not part of a shark’s natural diet.