Whale Ear Wax Keeps Record Of Ocean Pollution
Whale ear wax has a story to tell. Similar to the way tree rings record the history of the forest, whale "candles" detail the history of the ocean the whale lived in. The wax, which is a fatty tissue just like blubber, collects toxic chemicals and other particulates present in the water. New research shows that by examining a stick of whale ear wax, scientists can see exactly what pollutants the whale was exposed to in its lifetime.
Like Us on Facebook
Researchers from Baylor University in Texas studied whale earwax mined from a blue whale carcass that washed up on shore in California in 2007. According to Nature, the whale had died in a collision with a ship off the coast of Santa Barbara. Scientists from the Santa Barbara Museum of Natural History collected and preserved the ear wax from the dead whale's skull. NPR reports that the pillar of ear wax was nearly 12 inches long.
"It's kind of got that icky look to it," Sascha Usenko, an environmental scientist at Baylor University who was involved in the study, told NPR. "It looks kind of like a candle that's been roughed up a bit. It looks waxy and has got fibers. But it's pretty rigid - a lot stronger and a lot more stable than one would think."
The stick of wax taken from the 70-foot-long male blue whale had 24 layers ordered in light and dark stripes, each stripe representing six months of the whale's life. After studying the ear wax, Usenko and her team found traces of toxic chemicals at almost every stage of the whale's life. During the whale's 12 years, he was exposed to 16 persistent organic pollutants, including flame retardants and pesticides.
According to the Los Angeles Times, about 96 percent of the pollutants in the whale's ear wax were from pesticides historically used in the U.S. Many of these pollutants were probably passed on to the blue whale through its mother's milk.
"Persistent pollutants spiked in the baby whale's first 6 months, a period that accounted for 20 percent of the total persistent pollutants over the whale's 12-year lifespan," The Los Angeles Times notes.
The Smithsonian reports that the pollutants are also likely to have come from krill, the whale's main food source. The giant marine mammal can eat up to one ton of the shrimp-like krill every day, which means any contaminants the tiny creatures carry with them will be absorbed into the whale's body.
Researchers have asked other scientists to collect samples of ear wax from dead whales all over the world and send them their way to be studied.
Read more from iScience Times:
© 2012 iScience Times All rights reserved. Do not reproduce without permission.