This is one of the final stages of detection in our project. A laser is shined onto a sample and reflects off its surface, and the pattern that bounces back is a spectral fingerprint that reveals exactly which plastics are present. Those samples come from across the Great Lakes, including creatures as tiny as Daphnia and the fish that feed on them. The big idea is simple: to track plastic pollution, we have to know which plastics came from which samples. Here, each fingerprint becomes a sound, so you can hear what was hiding in the water.