Dolphin Echolocation — Nature's Sonar
Tursiops truncatus
Quick Fact
Dolphins can detect a golf ball-sized object at 100 metres using echolocation — and can 'see' inside other animals, detecting pregnancy and internal injuries.
About This Species
Dolphins produce high-frequency clicks through specialised nasal passages and focus them through a fatty organ in their forehead called the melon. The clicks bounce off objects and return to the dolphin, where they are received through the lower jaw and transmitted to the inner ear. This biological sonar system is so precise that dolphins can detect objects the size of a golf ball at 100 metres, distinguish between different materials, and even 'see' inside other animals — detecting the heartbeat of a pregnant female, for example.
Why It Matters
Ocean noise pollution from shipping and sonar interferes with dolphin echolocation, disrupting hunting, communication, and navigation. Quieter oceans are essential for dolphin welfare.
Transcript
Dolphins can see with sound. And what they can perceive through echolocation is, in some ways, more detailed than what we can see with our eyes. Here's how it works. A dolphin produces high-frequency clicks through specialised nasal passages — up to 1,000 clicks per second. These clicks are focused into a beam by a fatty organ in the forehead called the melon. The beam travels through the water, bounces off objects, and returns to the dolphin. The returning echoes are received through the lower jaw and transmitted to the inner ear. The dolphin's brain processes these echoes with extraordinary speed and precision — building a three-dimensional acoustic image of its environment. The resolution is remarkable. Dolphins can detect a golf ball-sized object at 100 metres. They can distinguish between objects of different materials — metal, plastic, rubber — even when they look identical. They can detect fish hidden under sand. And they can see inside other animals — detecting the air-filled swim bladder of a fish, the bones of a prey item, or even the foetus of a pregnant female. This is not just navigation. It's a form of perception that gives dolphins information about the world that we simply cannot access. Ocean noise pollution from shipping, sonar, and industrial activity is interfering with this system. Dolphins in busy shipping lanes have to echolocate more loudly, more frequently, and with less precision. It affects their ability to hunt, navigate, and communicate. A quieter ocean isn't just better for whales and dolphins. It's essential for their survival.