Sperm Whale at the Addo Canyon
By Sean Pike

Saturday, 3rd May 2025

Whilst having the largest brain on Earth, the most prominent, and certainly unusual feature of the Sperm Whale is the Spermaceti organ. It dominates the head and takes up to 33% of the animal’s entire body. It is an extremely powerful sonar, and is especially efficient where background noise is less, in deeper waters.

So why the evolution of this huge organ?

Sound Attenuation refers to the reduction of sound energy as it travels through a medium. Low frequency attenuates very little and is therefore the best sonar frequency option for a deep diving whale to use.

However, low frequency is difficult to directionalize, but if you can push it through a large structure, the energy can now be transmitted substantial distances with accuracy, and therefore dramatically increases the potential range of a signal.

Air is supplied to its sonar via the right nasal passage. It has a distinctive left-hand blowhole (as can be seen on the video), where the whale breathes through the left nasal passage.

This huge organ’s evolution now emerges, required for feeding on squid and other species at great depths. The Sperm Whale, clumsy-looking and strange on the surface, now becomes the supreme predator of the depths.

So why dive to such depths (between 1 – 2km)?

There must be substantial food resources at such depths, and a relative lack of competitors utilizing these deep-water food sources. They may also have better diving abilities due to their large size, if compared to many of the other deep-diving marine mammals. It is estimated that large physically mature males consume up to 1505 kg of food per day.

These dives usually last about 30 – 45 minutes (sometimes well over an hour), separated by about 7-10 minutes breathing on the surface. A major feature of the Sperm Whale’s life, these long deep dives can take up about 62% of an animal’s life.

This individual seen in the video is a very large male, as you can see the swollen crease of the spermaceti organ along the top of its head.

The Addo Canyon. A fascinating, ecologically-rich area with still plenty to be discovered.