You want to learn about the hidden history of the ocean? Look within, Nature says… within the earwax of a mighty blue whale:
The team, led by Sascha Usenko, a environmental scientist at Baylor University in Waco, Texas, extracted an earplug from a blue whale (Balaenoptera musculus) killed in a collision with a ship off the coast of Santa Barbara, California, in 2007 and found it had come into contact with several organic pollutants and contained high levels of the stress hormone cortisol as it reached sexual maturity.
“It’s difficult to recover time-specific information on chemical exposure for almost any animal,” says Stephen Trumble, a biologist also at Baylor and a co-author of the study, published in Proceedings of the National Academy of Sciences this week. That is especially true of the relatively rare blue whale, the world’s largest inhabitant.
Usenko and his team identified their specimen as a male aged about 12 years. During his brief life he came into contact with 16 persistent organic pollutants, including pesticides and flame retardants. Exposure to the most persistent chemicals was greatest in the first year — and accounted for one-fifth of his total lifetime contact — suggesting a transfer of contaminants from his mother in the womb and during nursing.
The best part of the article is a picture caption, which reads, “The extracted whale ear plug was 25.4 centimetres long.” That’s quite a timeline of chemical exposures.