This article originally appeared in Hakai Magazine. In several quiet rooms in a marine lab in southwest France, dozens of Pacific oysters sit in glass tanks, quietly living their oyster lives. Each morning, the lights come up slowly, carefully mimicking the rising sun, but at night the test groups’ rooms never fully darken. The dim glow simulates the light pollution that plagues many marine species—even in natural habitats. The results of the experiment, which were recently published, found that artificial light at night can disrupt oyster behavior and alter the activity of important genes that keep the animals’ internal clocks ticking. Damien Tran, a marine scientist at the Paris-based French National Centre for Scientific Research and one of the study’s authors, was surprised that even the lowest level of nighttime light that the team tested—“below the intensity of the full moon,” he says—was enough to throw off the oysters’ circadian rhythm. It’s especially remarkable, Tran says, when you remember that oysters don’t have eyes—at least not in the conventional sense. How oysters see is a …