Scientists studying drop in Erie algae blooms
Last summer’s drought led to significantly fewer toxic algae blooms in Lake Erie, according to Jeff Reutter, director of the Ohio Sea Grant College Program.
"We had hugely reduced phosphorus levels," Reutter said. "There was a 90 percent reduction (in phosphorus) from farmland runoff."
However, researchers are puzzling over a brief spike in blue-green algae that occurred in the lake's Central Basin during July. Those blooms appeared offshore of Lake County.
Although no hard data exists to confirm his suspicion, Reutter believes the algae came from an "upwelling" of phosphorus that washed into the Western Basin during 2010-11 and gradually migrated eastward. He explained the shallow nature of the Western Basin causes material collected there to wash away quickly. Central Basin waters are deeper and hold material longer.
Overall, blue-green algae blooms in the lake are weather related, Reutter said.
Rain carries phosphorus from fertilizer-laden farm fields, urban yards, and municipal sewage plants into ditches — then to tributaries of the lake.
Record rainfall during the summer of 2011 — especially in the Maumee River watershed — caused the toxic algae to reach record levels in the Western Basin that year.
The situation reversed in 2012 as the weather turned hot and dry. Rainfall in the watershed in 2012 was 10 percent of what fell in 2011, Reutter said.
Researchers had predicted blue-green algae blooms in Maumee Bay would be less than 10 percent of the 2011 number.
"It was just slightly more than that," Reutter noted.