BCM’s Stephen Trumble, Ph.D. and Sascha Usenko, Ph.D. have discovered a way to use whale earplugs to monitor contaminant and hormone profiles in whales, which has never before been possible to obtain. Through the earplug, they were able to gather data on the levels of the the whale’s cortisol, testosterone, and exposure to contaminants (i.e. pesticides, flame retardants, mercury), which proves both foreign and endogenous substances can be traced in the earwax of whales. Their study is published in this month’s issue of the Proceedings of the National Academy of Sciences of the United States of America.
Trumble and Usenko sought to answer the question of whether the concept of counting tree rings as an aging tool can be applied to whale earwax and its ability to chronologically store traces of chemicals. In the past, scientists have attempted to use whale blubber, which could only provide short-term information on exposures, and proved to be difficult to obtain.
“We are able to go back in time and analyze archived museum earplug samples that were harvested in the 1950s and examine critical issues such as the effects of pollution, use of sonar in the oceans and the introduction of specific chemicals and pesticides in the environment over long periods of time … There are a myriad of ways that we can analyze plugs for a better understanding of marine ecosystems and these endangered animals. There is so much additional information that can be mined from studying earplugs.” – Sascha Usenko, Ph.D.
With the new data gathered from the earplugs, the two professors gained a better insight into the effect humans have on whales across several generations. Analyzing the earplugs also reveal chronological information on whale’s biological processes.