Recent research into the sensory abilities of great white sharks off the coast of Southern California reveals that these predators may rely primarily on sound to detect the presence of humans in the water, rather than sight or smell. Scientists conducting the study at Cal State Long Beach's Shark Lab have found that sharks can hear and respond to noises created by people swimming, kayaking, or paddling on surfboards from distances of up to 100 feet.
Previous assumptions that sharks primarily used sight or odor to locate humans have been challenged by this research. Visibility underwater tends to be limited, and human scent disperses quickly, making these senses less reliable over distance. Instead, the study highlights that sharks’ acute hearing—including specialized sensory cells in their inner ears known as macula neglecta—enables them to pinpoint the location and type of sounds generated by different ocean activities.
Researchers used a multichannel hydrophone to record the distinctive sounds of freestyle swimming, kayaking, and surfboard paddling. When these recordings were played back underwater, juvenile white sharks exhibited different responses depending on the activity’s noise pattern. Freestyle swimming, which produces louder and more erratic sounds resembling those of struggling fish, was the activity most likely to attract sharks’ curiosity. In contrast, the quieter, more consistent paddling sounds were often ignored, and kayaking noises typically elicited little reaction.
According to Whitney Jones, who led the study, this is one of the first empirical demonstrations that sharks use auditory cues to identify and differentiate human activities from a distance. Observations also suggest that juvenile white sharks gradually habituate to human presence, becoming less reactive as they grow up around people.
Although encounters between sharks and humans are common in some coastal areas, bites are rare. Experts emphasize that sharks typically approach cautiously and lose interest upon closer inspection if they determine the target is not prey. Globally, unprovoked shark bites remain exceedingly uncommon, with only 65 incidents reported last year.
To minimize risk, researchers advise swimmers to avoid behaviors that might increase shark curiosity or misidentification, such as swimming alone, wearing shiny jewelry, or entering murky water. Groups of people produce louder combined sounds, which appear to signal to sharks that humans are not typical prey. Additionally, kayakers are cautioned against bringing fish or fish products onboard that could attract sharks.
Beyond safety recommendations, marine scientists stress the importance of overcoming fear-based misconceptions about sharks. Shark biologist Jaida Elcock of the Woods Hole Oceanographic Institution highlights that understanding these ancient creatures—survivors of multiple mass extinctions and key ocean ecosystem members—is vital. With over 500 shark species worldwide, none of which naturally prey on humans, continued research is critical to appreciating their ecological roles, especially as oceans face ongoing environmental changes.
The findings contribute to a broader effort to promote coexistence and respect between humans and sharks, emphasizing that curiosity does not equate to aggression and that education can reduce unnecessary fear of these complex predators.