A repellent for sea lampreys could be the key to controlling one of the most destructive invasive species in the Great Lakes, a researcher says. Michigan State University researcher Michael Wagner says dramatic effects are seen when scents from dead sea lampreys are poured into a tank of live ones, with the live fish making frantic attempts to escape. These reactions could be a potential game changer, he says. \"Sea lampreys are one of the most costly and destructive Great Lakes\' invaders,\" said Wagner, whose study appears in the Canadian Journal of Fisheries and Aquatic Sciences. The \"effectiveness of the odor combined with the ease in which it\'s obtained suggests that it will prove quite useful in controlling sea lampreys in the Great Lakes.\" A repellent, even in very small amounts, may prove to be more effective in diverting and corralling them, Wagner. \"It\'s kind of like a stop light, a noxious odor that causes them to run away from its source,\" he said. \"By blocking certain streams with these chemical dams, sea lampreys can be steered away from environmentally sensitive areas and into waterways where pesticides could be used more effectively to eliminate a larger, more concentrated population of sea lampreys.