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Researchers continue to monitor formation of toxic algae in Lake Superior

DULUTH, MN — Over the past decade, researches have observed something never seen before in Lake Superior: The formation of algae blooms.

The potentially toxic algae was spotted along the south shore last year, and researchers say it was by far the largest collection they had ever seen.

“We are definitely still trying to understand this phenomenon,” Dr. Robert Sterner, Director of the Large Lakes Observatory, says. “We probably will be for some years.”

It’s a phenomenon they’ve seen pop up only two times before in 2012 and in 2018.

“The good news is so far this year there have been no reports of blue-green algae blooms on the shore of the lake,” Sterner says.

Though those blooms have yet to be spotted in 2019, Sterner says the toxic algae is still present in the lake.

“We sampled it. It’s there in the lake.” Sterner says. “The fact that it hasn’t reached bloom status means it hasn’t grown to high densities yet and accumulated on shore.”

Sterner says there’s no cause for concern at this time, but like the lake, things can move rapidly.

“The sampling we’ve done so far has not indicated any level of toxicity that should be a concern,” Sterner says. “That type of algae can be toxic, however, so I don’t take a great deal of solace in the fact that we’ve not seen it yet. It could happen.”

A health concern issue that could have effect on the overall reputation of the great lake.

“Toxic water would be a game-changer in this lake,” Sterner says. “If people start to think about Lake Superior in a different way … that would be a very significant thing.”

Sterner says it’s highly unlikely for these algae blooms to pop up this late in the year.

If you do spot any blue-green areas, though, you’re asked to contact the Large Lakes Observatory, the National Parks Service, or the DNR.

Gamiel Hall

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