Lake Erie water was bluer than expected this summer after mild harmful algal bloom

Algae floats in Lake Erie's Maumee Bay in August 2014 after toxic bacteria from the harmful algal bloom forced a two-day ban on Toledo's drinking water. (Getty Images)

The bar chart shows the final sizes of the harmful algal blooms in Lake Erie, as well as the size of the HAB forecasted for 2018 in red.

CLEVELAND, Ohio - Federal forecasters overestimated the size of Lake Erie's 2018 harmful algal bloom, but few people were complaining Tuesday after the release of the final report of the summer bloom season.

The past summer's algal bloom was relatively mild, remaining much smaller than 2017's severe bloom, the fourth-largest on record. The 2018 bloom was only slightly larger than the mild bloom of 2016, and never spread as far as Cleveland in the lake's Central Basin, according to the report prepared by Rick Stumpf of the National Oceanic and Atmospheric Administration.

"Much of the lake will be fine most of the time," Stumpf correctly predicted in July during NOAA's annual HAB forecast event at Ohio State University's Stone Lab near Put-in-Bay.

Several factors figured into the summer's smaller algal bloom. They included wind, water temperature and favorable rainfall events, reducing the phosphorus runoff from agricultural fields in the Maumee River watershed during May, June and especially July, the report said.

High winds over the lake, climaxing in a storm September 9 and 10, severely disrupted the bloom and it never recovered, breaking up and dissolving by the first week of October, one of the earliest ends of the bloom ever.

While lake researchers observed some algal scums, they were less common than in previous years, and concentrated in the Western Basin.

Another factor may have been an unusual occurrence of a second non-harmful algal bloom containing green algae, a beneficial alga related to plants, said Justin Chaffin, a research scientist at Ohio Sea Grant and Stone Laboratory.

"There seemed to be more green algae in the water this summer, and the green algae competed with the cyanobacteria [in the harmful blue-green algae] for nutrients," Chaffin said, although he noted his conclusions still must be confirmed.

While the harmful blue-green algal blooms require calm conditions for growth, beneficial algal blooms containing green algae and diatoms depend on the wind to mix the water column, Chaffin explained.

Whatever the causes of the reduced harmful algal bloom, the results were welcome by those who enjoy swimming, boating and fishing on Lake Erie, and those who rely on the lake to make their living.

"It was a great Lake Erie year for fishing and recreating, with lots of blue water," said Sandy Bihn, executive director of the Lake Erie Waterkeeper organization. But she tempered her enthusiasm.

"Though this was a great summer, studies show that the nutrient flow into Lake Erie is not going down and that the algae problem remains a serious threat to water quality," Bihn said.

The bloom is an annual nuisance in Lake Erie, at times requiring beaches to be closed to swimming, game fish such as walleye and perch to migrate to cleaner water, and drinking water to be contaminated.

In 2014, dangerous bacteria from the bloom forced Toledo's water system to be shut down for three days. Ohio has signed a pact with Michigan and Ontario to reduce phosphorus entering the western basin by 40 percent by 2025.

"While the harmful algal bloom was low this year, nutrient flows into Lake Erie were still well above the targets needed to ensure a high probability of not suffering a bloom scenario every year," said Heidi Griesmer, a spokeswoman for the Ohio EPA.

To meet that reduction target, Gov. John Kasich signed an executive order in July calling for a tightening of state oversight of eight Northwest Ohio watersheds, and a more aggressive approach toward reducing bloom-feeding fertilizer runoff.

Last week, Kasich fired Agriculture Director David Daniels after he expressed concerns about the governor's order, which he called "unworkable."

Joe Cornely, a spokesman for the Ohio Farm Bureau, acknowledged "There is a lot more work to be done" by farmers in the Maumee River watershed, but they can't end harmful algal blooms on their own.

"Farmers are complying with new state regulations and adapting many voluntary fertilizer practices," he said. "Agriculture certainly is not going to take 100 percent of the credit for this year's bloom, but this drives home the fact that in bad years we don't deserve 100 percent of the blame."

Climate change poses a significant factor for farmers to overcome, he said.

"So much of what we are trying to figure out is how to lessen our environmental footprint in these changing weather patterns," Cornely said. "Ten or 15 years ago, we didn't have these 4-inch rainfalls in a 2-hour window, but they're becoming more common. We're trying to figure out what needs to be done on the farms to mitigate those occurrences."

Pete Bucher of the Ohio Environmental Council said he welcomed the smaller-than-predicted HAB, but said clean water supporters can't expect favorable weather patterns every year.

"We need to make significant progress reducing the root cause of the algae in the lake: Excess phosphorus seeping into our waterways," Bucher said. "Significant actions are needed to address the cause of the algae so Lake Erie communities don't have to worry about their drinking water every year."

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