By ALEXANDER SIMONE

Staff writer

Marion County Lake’s blue-green algae status became serious for Joe Robb when his 2-year-old grandson visited.

“Suddenly, we get a little more worried about it,” the Newton weekender said. “We’re not letting him drink it, that’s an easy one. When you think about breathing and developing lungs, you get to grasp, ‘what do we do or not do?’ ”

Blue-green algae poses the biggest threat to children 12 and younger, and pets, county lake superintendant Isaac Hett said.

The lake was put under an algae warning in April, but since then it has been downgraded to a watch. It remained under watch following last week’s tests.

“That is a positive thing but it doesn’t seem like it,” Hett said. “A watch is better than a warning, and they’re saying the water is OK. There are some of those blue-green cells but not enough to make it harmful.”

While Robb and his wife are careful in the water, their primary concern is the grandchildren.

“Do we want to own a place at the lake if our grandkids are at risk,” he said. “How conservative do we get with that decision?”

That could have serious implications for homeowners who are looking to sell, Robb said.

“Some of our neighbors have talked more seriously about selling for similar reasons,” he said. “What happens to values?”

While an extended blue-green algae watch could factor into housing prices, continued testing of the lake has not caused problems with listings, said Lori Heerey of Heerey Real Estate.

“It definitely has in the past,” she said. “People have asked about it, and sometimes when they’re looking there is an algae warning. It’s had some effect on real estate, but I can’t say it’s been huge over the years.”

Wayne Hoffman moved to the county lake in September, but the algae wasn’t a concern.

“I lived at the reservoir before, so I know all about the green algae,” he said.

The economic impact of blue-green algae warnings extends beyond potential housing prices, though.

“It’s hard on business,” Hoffman said. “That’s what Marion County needs, is business.”

If there are fewer residents at the lake, it can negatively affect local business profits, Robb said.

“The Mexican restaurant in Marion will tell you we’re regulars on Friday night,” he said. “It’s bound to have some impact. About half the lake is full-time and half is weekenders, so if the weekenders are there less often or bail out that becomes an issue.”

More than the algae, Hett said intense weather was the biggest factor he saw for decreased tourism.

Dredging the lake is one method for combating blue-green algae but it would cost a few million dollars. An economically feasible possibility is using chemical solutions approved by the U.S. Environmental Protection Agency.

“It doesn’t kill fish, but it kills the blue-green algae blooms,” Hett said. “A natural lake like ours will probably keep it away 14 to 21 days.”

The algae results from phosphorus and nitrogen in the water, but there are several likely culprits, he said.

“Yard fertilizer is a big one,” Hett said. “Any kind of fertilizer that comes in from rain runoff is a contributing factor. The geese and pasture fertilizers contribute; it’s all probably a little to blame.”