科学美国人60秒 SSS 2013-09-25
时间：2018-12-24 作者：英语课 分类：Scientific American(九)月
Cerumen, it's a lovely word a specially 1 considering that's called ear wax. And we are not the only species that produce this stuff, some whales build up waxes along with lipids and carotene protein into what's called earplugs. And researchers now know that examining this earplugs tells them about whale's lifetime and exposure to pollution. Alternative layers of dark and light in the plugs corelate to the seasons feeling or migration,so the plugs are used to determine a whale's age, think treeings. In the latest study scientist analysed the earplug of an endangered blue whale killed by a ship near California. They found that levels of stress for months doubled over the whale's life. They also found evidence that the whale has been exposed to plasticize such as DDT with a highest level during the whale's first six months of live. The whale was likely exposed to the plasticize in his mother's milk.
They also found a couple of peaks of exposure to mercury. The study is in the preceding of national academic sciences. Future earplugs should offer additional clues about whales' lives, so look for researchers to give new attention to leviathan remain.