NOAA Models Predict Mild Algal Blooms In Lake Erie For 2nd Year

Harmful algal blooms in Lake Erie are expected to be mild this summer for the second year in a row, according to the National Oceanic and Atmospheric Administration’s annual algae forecast.

Last year’s bloom was ranked at a 3 on NOAA’s severity scale. This summer, the bloom is forecasted to be about the same. That means much of the lake will be safe to swim in most of the time, according to NOAA researcher Rick Stumpf.

There are trace amounts of cyanobacteria, the type of algae that causes the blooms, he said, but there is no active bloom currently in the lake.

“There’s a hint of cyanobacteria in Sandusky Bay, but not very much of that at this time,” Stumpf said. “In the rest of the lake, for the other areas, we also don’t see any evidence of bloom from satellites.”

Blooms with a severity index of 5 or above generally pose greater risk to drinking water and recreation in Lake Erie.

The bloom could reach a 4.5 on the severity scale later this year, Stumpf said. Depending on wind variation and other factors like additional runoff, though, models show a risk that it could rise as high as a 6. Less wind and still waters allows algae to grow more, he explained.

“There’s a lot of variation within the same type of year, and that has to do with wind conditions,” Stumpf said. “Unfortunately, we can’t forecast this far in advance which direction the wind is going to blow.”

The 2020 forecast predicted algal blooms would be much more severe than they ended up being, Stumpf said, and so models for 2021 have been adjusted.

“That’s an important part of the exercise of doing a forecast and evaluating them, is to make sure that our models and forecasts actually can stay up-to-date and current and accurate,” Stumpf said.

This is the first time Lake Erie will see two consecutive years of mild blooms in more than a decade, Stumpf said. But that could be because Northern Ohio may be entering what’s known as a dry period, he said, with less spring runoff.

“If we end up in a drier period, we may go through a round of smaller blooms,” Stumpf said. “But we go back into a wet period, and we could have concern there.”

The region typically cycles between wet and dry periods every few years, Stumpf said. Recently, wet periods have lasted longer, he said, and that’s when the risk for problematic algal blooms goes up.

“That is consistent with the climate changes, which have shown a slow increase, particularly in spring rainfall, in this area,” Stumpf said. “It’s a little hard to presume what may happen.