Zebra mussels continue to threaten Manitoba waterbodies

The invasive aquatic species, zebra mussels, have made their way into bodies of water like Lake Winnipeg. They’ve become so prolific, that Manitoba Hydro is now having to spend millions to control them, as efforts are being made to stop them from spreading into other lakes and rivers.

“Zebra mussels are really the poster child of invasive species, and they can cause real problems for both people and for the ecosystems they invade,” said Scott Higgins, a research scientist with IISD Experimental Lakes Area.

Mathew Bannerman, an environmental specialist with Hydro Hydro, says zebra mussels were detected in Manitoba’s Nelson River three years ago. Manitoba Hydro has had to implement additional measures to combat these invasive species, as they have been clinging on to some of their generating stations.

“The last couple of years, we have had to chemically treat some of our generating cooling assets and our fire protection systems to prevent impacts,” said Bannerman.

The treatment program is costing Manitoba Hydro north of $2 million annually. Bannerman says there is a constant worry that the zebra mussels will spread to other lakes and rivers, which will impact or even damage hydro infrastructure.

“We are keeping an eye out on the waterbodies where we have our operations based out of.”

Zebra mussels are not native to Manitoba or North America. They were brought over to the Great Lakes in the ballast water of ocean-going freighters from Eastern Europe.

Zebra mussels attach themselves to solid surfaces, aquatic vegetation, or to each other. Research Scientist Scott Higgins says zebra mussels filter algae out of the water, which isn’t a problem in the short term, but becomes an issue when the number of zebra mussels becomes very high.

“They can reach over 100,000 individuals per meter squared of the lake bottom. At the population level, you put all these mussels together, they can filter an enormous amount of water and plankton out of the water and that is the base of the food web. The problems can cascade to trophic levels like all the way to the fish.” said Higgins.

Pam Jackson, the Mayor of Winnipeg Beach, located about 70km north of Winnipeg, says zebra mussels have riddled their beaches for several years. She says the zebra mussels will have lasting negative impacts on the fishing industry.

“The fishing industry is pretty big on Lake Winnipeg. Both here and as well of Gimli, and north of Gimli. The fishing industry is very big. That is where we get all of our fresh pickerel from,” said Jackson.

Invasive species specialist Candace Parks says combating these pests long term, will not be a walk on the beach…

“Sharp shells on the beach, on shorelines and this will be a continual issue because wind movement will just move them back on the beach. It’s not like cleaning up one day and you’re done. It will be an ongoing issue,” said Parks

While it’s too late for Lake Winnipeg, prevention is possible.

Higgins says, “You just have to make sure that you really clean your boats, or whatever infrastructure you are moving out of those systems into other systems. They need to be decontaminated before they’re moved.”