They phrase it in scientist-speak: "It will therefore be prudent to further reduce the flow of anthropogenic nutrients to Walden Pond," researchers write in the journal PLOS One. The translation for non-scientists: Stop peeing in Thoreau's beloved pond. Scientists from Paul Smith College in New York assessed the health of the 64-acre pond in Concord, Massachusetts, and concluded that swimmers who decide not to hold it are playing a significant role in the pond's degradation, reports the Boston Globe. All those "anthropogenic nutrients" they're releasing encourage the growth of pond-choking algae. In fact, lead researcher Curt Stager says it's so bad he favors a ban on swimming altogether.
“That would be ideal for the sake of the lake," says Stager. "I think it would be a tough sell for the public," he adds, given that the pond is a big attraction for locals and tourists alike. By analyzing sediment cores at the pond's bottom, researchers were able to trace the rise of phytoplankton roughly to the 1920s—about the time tourists and swimmers began turning up in large numbers, reports Live Science. Urine isn't the only culprit. Researchers also pointed to warmer temperatures, noting that climate models expect that trend to continue for New England. And that poses a double-whammy: Not only do warmer temperatures foster the growth of algae, they drive more swimmers to the pond. (What would Thoreau think of this video game based on the pond?)