Duckweed turns coves at county lake bright green

By ROWENA PLETT

Staff writer

Mike and Tracy Carroll have lived on a cove at Marion County Lake for 2½ years, and this year they are noticing a large amount of green algae on the water.

Tracy Carroll said the bright green color is from duckweed that floats in the water or catches on moss. The duckweed floats with the wind when it is in open water.

“We really would like it to be gone,” she said.

They are afraid for their dog if he gets in the water, even though the duckweed is not toxic like blue-green algae, for which the lake has remained under a state watch or warning since May 1.

The couple have their dog leashed when they are outside, and he can’t reach the water unless it rises after a big rain.

Their deck extends out over the water. Carroll said the water covered their deck two times this spring.

There is no bridge on Lakeshore Dr. to the south, only culverts under the road, so the water doesn’t flow, Carroll said.

Her husband said he thought the freezing and thawing that occurred in early spring helped to loosen the duckweed and bring it to the surface.

Lake manager Isaac Hett said the coves at the north end of the lake are shaded by trees, and when the south wind blows, it carries algae into the cove, where it has no way to escape.

Hett said the problem might be worse this year because of this past year’s drought. The low water level allowed sunlight to reach to the bottom, where the duckweed grows. This year, it floated to the surface when the water warmed.

“Temperature has a lot to do with it,” he said.

Hett said one possible solution would be to pull the weeds out manually. Another solution might be to place grass-eating carp in the water to eat the duckweed, but the whole lake would have to be blocked off, he said.

For now, it looks like people who live on the coves will have to learn to live with the algae and take the necessary precautions to protect their health and the health of their pets.