A new research tool to safeguard drinking water is now keeping a watchful eye on Lake Erie. This week, a robotic lake-bottom laboratory began tracking the levels of dangerous toxins produced by cyanobacteria that bloom each summer in the lake's western basin.The goal is to provide advance warning to municipal drinking water managers and thereby prevent a recurrence of the water crisis that left more than 400,000 Toledo-area residents without safe drinking water for about two days in early August 2014 due to high levels of microcystin toxins.