This picture is from early April, taken at Center Lake. The algae’s scientific name is Planktothrix rubescens, otherwise known as a red bloom. Photo provided.

News Release

WINONA LAKE – Can blue-green algae be red in appearance? Apparently so.

The cyanobacteria pictured above is a kind of blue-green algae but can feature some reddish tints. Its name is Planktothrix rubescens for its bright reddish-pink tint, according to information provided by the Lilly Center for Lakes & Streams.

Unlike most blue-green algae, which typically bloom in warmer months, rubescens can thrive in cold weather. That explains this bloom and a similar one that occurred on Center Lake in Warsaw in the winter of 2018.

Nathaniel, one of our student team members, was taking a leisurely walk near the Center Lake wetlands when he spotted the bright pink algae bloom. Adrienne, our research program specialist, and Ry, another team member, went to sample the bloom for lab analysis through the Lilly Lakes & Streams 

Later that same week, a resident of nearby Pike Lake reported to the Lilly Center a separate, but similar-looking bloom, which our team also sampled and identified.

Rubescens can produce toxins, like other blue-green algae species. It’s always wise to stay away from water that appears questionable! Blooms like this one typically dissipate within a day.

Want to learn more about blue-green algae? Click here.