Curiosity – Bluewhale’s Health Certificate

Health certificate: grease-plug of the inner ear offers inspection about the fitness of whales.

Did you know that Bluewhale “record” a kind of individual logbook? Of course that happens unknowingly and they don’t have to remember writing entries.

In this biological “health certificate”, the records are self-generated in a biochemical way and provide usuful information about the lifecycle of the marine giants.

Between the tiny little outer ear of the whale (invisibile from outside, because it degenerated during evolution) and the inner ear, a substance similar to wax is accumulating in their ear canal. Since whales don’t use cotton swabs (like human does), the ear-wax is growing during the lifespan of the whale and turns into a precious archive, regarding scientific research. By using this substance from a dead whales ear canel, experts are able to get important data about the health condition and the way of life of the animal. It appearance is like a cylinder and it is growing bigger with the age.

By analysing the whales earwax, scientists can determine the exact age of the animal (up to only some months difference). Also residues of hormones and chemicals can be detected. Depending of the result of the analyse, this can lead to a conclusion about the status of health and sexual maturity of the whale. For example, if there are high concentrations of cortisol (a stress hormone) in an ear wax layer, could this be a sign that the animal were stressed. Chemicals like pesticides , PCB’s, heavy metals, oil deposits and other substances found in the wax can point out, that the whale eventually lived in polluted marine areas. Concentrations of the sex hormone Testosteron gives evidence about the status of sexual maturity of the animal.

At the same time analyses of the whales ear-wax informs us about the impact of human society on the marine ecosystem in general.

By your guide Astrid Haas