Winter algae strain creates its own ice, could worsen Lake Erie's 'Dead Zone'

Published: Jan. 31, 2018 at 5:03 PM EST
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You may think that Lake Erie closes for business come winter. But the lake's freighters still run, and fish still swim at the bottom.

Algae still lurks under the ice, too, as researchers recently discovered.

A special type of diatom algae doesn't just survive, it thrives, in Lake Erie in the middle of winter. And now some scientists think that that contributes to Lake Erie's famous 'dead zone.'

“That may fuel seasonal hypoxia later In the year,” Dr. George Bullerjahn said. He is a “Research Professor of Excellence” at Bowling Green State University and a renowned algae expert.

As winter algae fades in spring, it eats away precious oxygen and can kill schools of fish. These two scientists first noticed the algae while on an ice cutter a decade ago.

“We were thinking of it more as an adventure. Didn't really expect it to change the direction of some of our research,” Dr. Mike McKay said. McKay is the Ryan Professor of Biology at BGSU and is also an algae expert.

Unlike our neon summer microcystis mats, these are brown. But diatoms are certainly not all bad...

“The important difference here is that these algae that we find mainly in the winter time don't produce direct toxins,” Dr. McKay said.

But how can this algae survive beneath the ice in the dead of winter? Look at this video of a BGSU experiment. A bacteria on the algae helps the algae float and get light, by making its own ice!!!

“Allows them to make ice crystals at temperatures where the water would otherwise not freeze. Allows them to ascend up to the surface… adding to the ice cover, or maybe even starting the ice cover,” Dr. McKay said.

Turns out, harsh winters like our current season (2017-2018) could be good for a smaller summer bloom.

“Having a mild winter, may actually promote a larger bloom in the summer, because there'd be more nutrients to start,” Dr. McKay said.

Where do our infamous blue-green scum mats disappear in winter?

“You'll see microcystis fall out of the water column, and form these resting cells that over-winter,” Dr. Bullerjahn said.

“But the numbers we find, the cell numbers, are really low,” Dr. McKay said.

Drs. Bullerjahn and McKay are working with the U.S. Coast Guard and their ice cutters to gather samples in difficult times, and places, during the winter.