If you’ve ever been to a museum, you know that they often have odd collections, like pinned insects, broken pieces of pottery, and so on. However, did you know that the majority of every museum’s collections are not displayed, but kept in storage for research? The Smithsonian’s National Museum of Natural History actually has a large collection of whale earwax it’s been amassing since the 1950’s. Why?
Known as “earplugs,” collections of whale earwax reveal a lot about the whale it came from. It’s comparable to the rings of a tree in that you can tell a whale’s age. You can also tell by the difference in the layer colors when the whale was migrating or when it wasn’t finding food. Recent studies reveal that studying the wax teaches us a lot more. 
Throughout the years, hunting has endangered a variety of whale populations. The stress of noise pollution, being chased by ships, and injuries shows up in the whale’s earwax. Today, whales are threatened by other factors like climate change and ocean pollution. Scientists are now beginning to compare newer earplugs with ones from the past to find out just how extensive human impact is.
One of the most interesting discoveries comes from Stephen Trumble and Sascha Usenko from Baylor University. They found 42 chemicals, including pesticides and mercury, that do not naturally appear in a whale’s body. The study is even able to say that many chemicals are passed down from a mother to a child through her milk, because they appear in the first layer of wax.
The presence of these chemicals is clearly due to human activity. The next step is to keep examining past samples and comparing them to newer ones to track the impact. Thanks to the weird (and kind of gross) collection of earplugs, scientists can show how pollution is damaging the ocean ecosystem, and hopefully work towards a solution.