The Surprising Science of Whale Earwax

Who doesn’t love whales? They are majestic, intelligent, and mysterious. The blue whale is the largest animal to ever exist, and the bowhead whale can live for more than 200 years! How, exactly, do scientists know how long a whale lives? Turns out it is their cerumen—wait, what?

Cetologists are scientists who study whales. They can cut into a plug of earwax from a whale, which can be more than 10 inches long, and much like looking at the rings of a tree, determine the age of the whale from which it came. Earwax from blue whales, for example, forms rings approximately every six months.  These rings, or laminae, inform cetologists how old a particular whale is. But it turns out, these plugs can tell scientists even more than just their age. From an earwax plug, chemicals and pollutants from the water can be analyzed. The stress hormone, cortisol, can also be measured, and research has confirmed that cortisol in the earplugs of whales increases as whaling increases (or decreases). Even though whaling was banned over 50 years ago, cortisol levels are still high in whales. Cetologists believe this is due to ship noise, climate change, and other factors. 

Who knew earwax was so interesting? Audiologists did!