University of Vermont

Vermont Water Resources & Lake Studies Center

Blue-green Algae Kills Thousands of Fish in Missisquoi Bay

from the Montreal Gazette

MONTREAL - Paul Steiche remembers growing up on the water in Philipsburg and being able to see straight to the bottom of the lake.

Having only left to attend college and university in Montreal, Steiche now co-owns a café in neighbouring Bedford, and repeatedly mentions how beautiful his hometown and the Missisquoi Bay region are.

But the 34-year-old new father said he won’t allow his son to experience the same happiness that is being on the water, at least not anytime soon.

The bay, which is part of Lake Champlain, was overrun Thursday by blue-green algae.

Cyanobacteria, its scientific name, is naturally present in Quebec’s lakes and rivers in low concentrations, according to the environment ministry’s website.

But if the conditions are right, the algae multiplies and forms a bloom, what it’s called when it’s visible to the naked eye. And this year, the conditions were more than right.

The algae feed off of phosphorous, an element that can come from natural sources, but is also found in manure, compost, fertilizer, septic systems and waste water that has not been properly treated.

The Missisquoi Bay region was one of many affected by last year’s flooding. The flood waters introduced many of the ingredients needed to create a phosphorus surplus into the lake water.

The algae also thrives in warm temperatures and under UV rays.

Add low water levels and the natural shallowness of the bay, which means the sun can easily warm not only the water, but the soil beneath it as well, and conditions were rife this summer for the formation of blooms.

The phenomenon occurs every year in the Missisquoi Bay. What was abnormal is the extent of the problem.

Doug Shaver has lived in Philipsburg since 1980, but his family has been living in the area for generations.

He said the water was so murky Friday it seemed as though the bay was filled with blue and green paint. A white foam was also visible in the water.

The abundance of algae means there’s less oxygen in the water, which in turn kills the fish.

“You could take a stick of dynamite and throw it in the lake and watch the fish come up to the surface. It would be the same effect,” Shaver said.

He estimated that anywhere between 3,000 to 4,000 dead fish are piled up on the shore.

Mayor Réal Pelletier has lived along the shoreline for 20 years, and said he’s never seen a sight quite like the scene on the lake now.

He says at least two kilometres of shoreline is covered with rotting fish.

Pelletier said he contacted the environment ministry and the natural resources and fauna ministry to alert them of the problem. Though employees of the environment ministry came to test the water, both ministries told him they could not help clean up the fish.

They did suggest the municipality undertake the cleanup operation. But when neither agency could guarantee workers wouldn’t be harmed in the efforts, he decided against it.

Representatives from both ministries were unavailable Saturday to explain their policies when a town reports a case of blue-green algae of this scope.

Shaver explained the area’s residents are used to the bacteria’s annual appearance and the unpleasant but tolerable smell that comes along with it. But this year, it was something else entirely.

Steiche described the stench as a mix of rotting fish, “hot algae smell,” and pig manure. Pelletier likened it to a septic tank.

The smell was so vile that residents were forced to close their windows in order to escape it.

Philipsburg has also been under a boil water advisory since the beginning of last week, but Pelletier said he was told by the public safety ministry it was not related to the algae problem.

When the temperature cooled off and the wind picked up Friday night into Saturday, the blooms began to disappear and the water soon cleared up.

Though the bay is no longer murky, the reason why the blooms flourished with such fervour is still a mystery.

Theories abound, but no one knows for sure which and to what extent the common factors contributed to the sequence of events that unfolded Thursday into Friday.

“I’m waiting for the results from the (environment ministry), Pelletier said. “I hope they’re going to do more tests and find where it comes from, because I know the water is really low this year, but it can’t be only that.”


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