Thunder Bay

Low Lake Superior ice levels threaten wetlands

Waves crashing against the shoreline are an unusual scene for mid-February on the north shore of Lake Superior, and low ice levels are not a good sign for wetlands.

Two university professors are worried about the lack of ice on Lake Superior.

Waves crashing against the shoreline are an unusual scene for mid-February around Thunder Bay, and the low ice levels are not a good sign for Lake Superior's wetlands.

Pat Chow-Fraser is a wetland ecologist at McMaster University. She said when the lake is not covered by snow, there's more evaporation. That means lower water levels in the spring.

"Once the water levels go down beyond a certain point, the wetlands just go dry. So that's a big concern," she said.

Chow-Fraser said 80 per cent of Lake Superior's fish have to use the wetlands during their life cycle. 

She is not the only one concerned.

Walter Momot is a biology professor at Lakehead University who specializes in fish. He said low ice means loose ice. He said loose ice can displace vegetation and disrupt spawning season for smaller fish in the the wetlands.

"What do big fish eat? They eat little fish. And if there's no little fish to eat ... there you go. There's one effect that's just plainly obvious," he said. "The marsh provides an important area for small fish and if the ice ... tears up enough of the marsh, it would affect a place to live for the little fishes."

He said when the lake is not covered by ice and snow there's more evaporation. That lowers the water levels in the spring. He said that can dry up the wetlands even more.

"We have to have spring rains or the ground water doesn't recharge or we're in big trouble. And that's what feeds these marshes," he said. "Water levels are very low and wetlands have taken a beating. If you go to Mission Marsh [near Thunder Bay] it's gone."