GROVE, Okla. — Pete Norwood on Tuesday was counting up the losses.

The Grove marina owner estimated that he and his partners lost 30 to 40 percent in business over the Fourth of July weekend.

That’s a bitter pill for Norwood, one of the owners of Honey Creek Marina. In February, record snowfall caused marina roofs to collapse. That was followed by record low temperatures of 28 degrees below zero.

“Then came May, and the same storm that took out Joplin (the May 22 tornado) spawned over Oklahoma, taking out more of our marinas and some of our homes,” Norwood said.

“After that came Memorial Day weekend, and over two days we had 10 inches of rain, which raised the water and brought in debris. It was a miserable weekend.”

On Friday, just as businesses on Grand Lake were preparing for the Fourth of July weekend crowds, came the warnings from the Grand River Dam Authority board. The public was — and still is — being advised to stay out of the water because of a large bloom of blue-green algae. The Oklahoma Department of Environmental Quality said the danger is the algae’s ability to produce and release toxins into the water. If the toxins are swallowed, reactions might include upper respiratory problems, eye irritation, vomiting and diarrhea.

The warnings could not have come at a worse time, said Norwood, who has lived at Grand Lake full time since 1994, and has co-owned the 100-slip marina, restaurant and shopping center since 2003.

“We were all looking forward to the Fourth, trying to bring back our customers we’d lost and recoup our losses from the other weather situations,” he said. “Then we get this algae bloom, and now we’re down again.”

‘Way overblown’

Grove City Manager Bruce Johnson said the holiday weekend typically draws tens of thousands of tourists to Grove — the biggest city on Grand Lake, with a population of more than 6,000. Like many communities in the area, it relies on lake-related revenue from an increase in camping, restaurant traffic, golfing, and purchases of fuel and supplies.

But a week ago Tuesday, samples by the Grand River Dam Authority found a level of blue-green algae 2 1/2 times the World Health Organization standard for a moderate health risk. In some coves in which scum was floating, samples tested at 18 times the standard.

Blue-green algae are free-floating, microscopic organisms that are naturally present in reservoirs, lakes and streams. Jay Wright, an environmental programs manager with the Department of Environmental Quality, said that given the right amount of sunlight and nutrients, the algae reproduce rapidly and turn a clear lake or pond into what appears to be pea soup.

“This is the first time we had observed it in Grand Lake to this degree,” Wright said.

His theory for last week’s unique bloom is that flooding in May washed more than the usual amounts of nutrients — specifically, nitrogen and phosphorus — into the lake. Then the weather changed almost immediately to very hot, sunny conditions.

The National Weather Service reported that June was the second hottest month on record in Tulsa, 100 miles to the west.

“From our perspective, it is our duty to alert the public when we feel there is a threat to public health and safety, and we felt it was important,” said Erin Hatfield, DEQ public information officer.

Doug Cox, a member of the Oklahoma House of Representatives and a longtime emergency room physician at Integris Grove General Hospital, said his staff has not seen any illnesses that could be attributed to algae-related health issues.

“It was the same mix of symptoms we see on any busy summertime holiday,” Cox said. He described the reports of algae affecting public safety as “way overblown.”

“You would have to ingest an awful lot as a human being for it to impact you,” he said.

U.S. Sen. James Inhofe, according to the Tulsa World, was hospitalized last week because of an upper respiratory illness he said he contracted from swimming in Grand Lake, where he has a home.

“There is no question,” the 76-year-old Republican told the World of his routine dive into the lake last Monday morning. “That night, Monday night, I was just deathly sick.”

By contrast, Chuck Perry, a Realtor who is president of the Grand Lake Association board, said he purposely spent the holiday weekend in the water.

“I made it a point of spending a lot more time in the water than I normally do to show people that it isn’t the huge concern that DEQ has made it out to be,” he said. Perry said that in talking with business owners in the area, he found “an awful lot of people suffering economically because of it.”

“The DEQ cried wolf a little too loudly,” he said.

Running its course

Not everyone saw a downturn in business. Joyce Duke said that in an odd twist of fate, her businesses — Big Shots, Shebang and the Den of Uniquity — had record-breaking nights.

“I guess people came to the lake, but instead of being out on it they spent time in the bars dancing, eating, drinking and shopping,” Duke said.

Tad Jones, executive director of the Grand Lake Association, said he wasn’t sure precisely how the warning affected businesses, but that “it was a concern by many that there was an overreaction.”

Jones said he spent Tuesday gathering information on how the weekend went, and he will be doing so for the next week or two.

“We’re also looking at solutions,” he said. “How did this happen? How can it be stopped in the future? How bad is it?”

Wright, with the DEQ, said nature must now be allowed to run its course. An increase in wind, as well as a fluctuation in temperatures, sunlight and water levels could contribute to the eventual dissipation of the algae, he said.

He said property owners are being told that they can help prevent such algae blooms by avoiding using more lawn fertilizer than the recommended amount, by using phosphorus-free fertilizer when possible, by avoiding applying fertilizer where the runoff can filter into storm drains, and by maintaining native vegetation along shorelines and streams.