Sharks Can Hear for Miles

While a shark’s ability to smell blood in water a quarter of a mile away is well known, their ability to hear prey from miles away may be the bigger meal ticket.

Images of bloody chum undulating through ocean currents has cinematic gory appeal; however, a shark needs to be in relatively short range (less than a quarter mile) to pick it up. Also, the rate at which the smell travels is dependent upon currents, so sensing the odiferous lure is relatively short range in comparison to estimates on how far a shark can hear potential prey. 

A shark’s “inner ear” is a dual-purpose system called the acoustic-lateralis system. The configuration allows sharks to perceive sounds between 10Hz­­­–800Hz that travel great distances through water. The lateral line runs just under the skin, flanking each side of the apex predator. The lateral lines allow detection of additional vibrations, further orienting sharks to their environments and clueing them toward potential prey. Additionally, sharks are capable of electroreception, the ability to detect electrical fields. Together, these amazing structures form an excellent internal global positioning system (GPS) in the murkiest of waters.

Sharks are most attracted to low-frequency, erratic thumping sounds that mimic prey in distress. In the Discovery Channel’s Bride of Jaws (2015) documentary, researchers used an underwater speaker playing heavy metal music (low-frequency dominated music) to successfully lure great whites for filming purposes. The acoustic method is gaining popularity as it may be more effective at attracting sharks than the traditional chumming techniques, often reducing the time it takes for sharks to appear. 

References

AZ Animals. (2021) How far can sharks smell blood? (accessed July 26, 2022).

Discovery Shark Week. (2015) Bride of jaws. S2015 E6. (accessed July 26, 2022).

Martin RA. (2003) Biology of sharks and rays. (accessed July 26, 2022).