"They were eating oysters like crazy," an archaeologist says of Native Americans who visited what is now the coast of Maine for thousands of years. And it's a good thing they did. The piles of discarded oyster shells created by hungry Native Americans over centuries are an irreplaceable source of information on their cultural practices, as well as the environment and climate of Maine millennia ago. "If you want to know what was in the western Gulf of Maine 3,000 years ago, this is how you're going to figure that out," Dr. Alice Kelley says. But the New York Times reports Maine's more than 2,000 shell piles, or middens, are disappearing thanks to climate change and rising oceans. "They are disappearing so fast, and the knowledge that is within those middens will be washed out to sea," says Donald Soctomah, historic preservation officer for two Passamaquoddy tribes.
Middens protect Native American artifacts from acidic soils because of the calcium carbonate in the shells. Stone tools, ceramics, and bones have been discovered in the shell piles, and artifacts from one midden were found to be more than 5,000 years old. "The shell middens are a link to the past and give us an idea of how life was at a certain time," Soctomah says. However, there are so many middens there's no way to study and save them all, the Mount Desert Islander reports. Kelley is securing funding to scan the shell piles with ground-penetrating radar to figure out which are most worthy of study—and which are most endangered by erosion. In a case illustrative of the time pressure Kelley and her team is under, they attempted to use radar to scan a midden recorded just 49 years ago only to find it had disappeared into the sea. (Read more archaeology stories.)