ST. MARYS, Ohio — State regulators say tests on water taken from Ohio's largest inland lake reveal that it's no longer safe for swimming and water skiing.
The testing was prompted by an algae outbreak on Grand Lake St. Marys in western Ohio.
State regulators posted warning signs over the weekend, advising residents and tourists not to have any contact with the water.
Tests on water samples from the lake show the presence of a liver toxin and a nerve toxin coming from the algae. It's not clear what caused the blue-green algae to bloom.
Warning signs also went up at the lake last year after the discovery of a type of algae more common in Lake Erie. Contaminants such as fertilizer and manure from nearby farms contributed to the earlier algae outbreak.