Who ya gonna call? If you spot a suspected aquatic invader, where you report it depends on the critter or weed. Remember to take photos with a camera or, even better, geo-tag them with a smartphone. Take a snapshot that shows just where you saw the invasive species, such as a streambed, lake or pond. Next, photograph the whole animal or plant and then add close-ups of distinctive features. For example, check mussels for “byssal” threads that attach them to surfaces and photograph...