The California Department of Water Resources (DWR) has issued a danger advisory for San Luis Reservoir in Merced County due to a harmful algal bloom that can expose people and animals to potentially dangerous toxins. DWR announced the danger advisory Friday, Oct. 9, and reiterated the warning through its official social media accounts, urging visitors to keep themselves and their pets away from algal blooms. The announcement follows an earlier warning documented by the California State Water Resources Control Board. Records updated Oct. 2 showed that San Luis Reservoir was already under a lake-wide warning advisory, which prohibited swimming and advised visitors to avoid algae and scum in the water. The latest danger designation represents an escalation from that earlier warning and is the highest of California’s three harmful algal bloom advisory levels.