From the Columbus Dispatch:
Warning signs around two state park lakes were removed yesterday as blooms of toxic blue-green algae continued to fade statewide.
Ohio Department of Natural Resources officials say the water at Stonelick State Park in Clermont County and the lake at Burr Oak State Park in Athens and Morgan counties are now safe for swimmers. Two weeks of tests detected only a trace amount of the liver toxin microcystin at Stonelick and no toxins at Burr Oak, said Heidi Hetzel-Evans, a Natural Resources spokeswoman.
Officials also said Cutler Lake at Blue Rock State Park in Muskingum County and the LaDue Reservoir in Geauga County are now safe for boaters. Tests found lower concentrations of toxins at both. However, visitors still are advised not to touch the water.
The changes leave six public lakes and two Lake Erie-area state park beaches where officials fear as many as four algae-produced liver and nerve toxins could pose a health threat to visitors.
Blue-green algae, or cyanobacteria, are common in most lakes and streams but grow thick on hot summer days in water polluted with phosphorus from farm manure, fertilizers and raw sewage. Blooms have been dwindling as temperatures have declined.