Bowhead Whale Earplug Can Be Used for Lifetime Chemical Analysis

In nature, there are several proxies used in aging; there are coral and carbon signals, sediment and ice cores contaminants, dendrology in trees, and whale earplugs. For over a century, whale earplugs have been used as a proxy for age in baleen whales [14]. Whale earplugs contain wax that is accumulated and preserved over a lifetime and because feeding and fasting from migration patterns results in different colored waxy secretions, the age of the whales can be estimated. Thus far, earplugs have been recovered in some baleen whale species as well as the sperm whale (a toothed whale). It was previously thought that the bowhead whale (Balaena mysticetus) did not produce earplugs. However, this research reveals that the bowhead whale does produce earplugs and that these earplugs can be used as an aging matrix [15]. Our results come from a bowhead whale believed to be a female 50-year-old whale. Previous research determined that aging consists of counting light and dark lamina laid down biannually [15]. Using gross morphology analysis of this female bowhead plug it was discovered that lamina follow a typical pattern [20] A novel technique was developed to separate the bowhead lamina. This process revealed 65 distinct laminae, which were analyzed for cortisol and testosterone composition. The objective of this thesis was to determine a method to separate lamina in a bowhead whale earplug.