New water warning at Ohio's largest inland lake

ST. MARYS, Ohio - Blue-green algae is blooming on Ohio's largest inland lake, prompting state regulators to tell visitors to beware of the water for the second straight summer.

Warning signs about toxic algae were posted last year at Grand Lake St. Marys, but whether the current outbreak poses a significant danger to boaters and swimmers is not yet clear, officials said.

"Our preliminary results indicated it's a different species and it's capable of producing a number of toxins," said Dina Pierce, spokeswoman for the Ohio Department of Environmental Protection.

Pierce said Tuesday that initial testing for three toxins last week did not reveal readable quantities, but that caution is still warranted because the hazards may be present at undetectable levels.

Given the concerns about potential risk to health, the Ohio Department of Natural Resources on Friday posted signs warning people to avoid contact with "visible surface scum" on the 13,500-acre lake, which sits between Toledo and Dayton.

Pierce said lake visitors should skip contact with the water if possible, but if they do go in, they also should avoid ingesting water and wash off after contact. She said pets should be kept out of the water.

Among the health issues the toxins can pose are potential gastrointestinal problems and skin irritation.

Brian Miller, assistant park manager at Grand Lake St. Marys, said Tuesday he hadn't heard of potential visitors canceling recreation plans. The algae comes and goes and isn't visible in some areas.

"You can still use the lake, just avoid those areas," Miller said.

The lake also had an algae problem last year, said Milt Miller, fundraising chairman of the Grand Lake St. Marys Restoration Commission, a private group that has raised money for water-monitoring equipment.

The lake takes a lot of watershed from nearby farms, and without a river connection to flush nutrients out, algae grows when the sun gets hot, he said.

Warnings also went up at the lake last year following the discovery of a type of harmful algae more common in Lake Erie. Contaminants such as fertilizer and manure from nearby farms contributed to that outbreak, officials and activists said.

Pierce said tests from earlier last week showed that a toxin found in the water last year is in the lake this year at low levels.

The lake's annual number of visitors dropped to 687,000 in 2009, from more than 737,000 a year earlier.