A translation by Judith Turcotte.
The zebra mussels have invaded the St. Lawrence River and our lakes. The rapid progression of this invasion took us by surprise. We know today that the female zebra mussel can hatch up to 1 million eggs per reproductive season. This rate of reproduction allows the mussels to colonize new habitats at an unimagined speed and to attain the density of 100,000 specimens by square metre.
The zebra mussels are small freshwater mussels who were detected in the Great Lakes in the 1980s. They subsequently spread to the St. Lawrence River and into a multitude of the province’s bodies of water. Among others, we find them in the Memphremagog, Brome and Mistassini lakes. They originate from Ukraine and the south of Russia and most likely arrived in the ballast water from the ships arriving from Europe. These little creatures have had a significant impact on our aquatic ecosystems.
They are numerous and filter up to one litre of water daily withdrawing the plankton, an essential nutrient to other species. They also attach themselves to solid surfaces obstructing the water intake from power plants and water treatment plants. When they were discovered in the river, many observers and journalists predicted a short-term disaster. However, the zebra mussel is not the only one to have immigrated here. The quagga mussel, bigger than the zebra mussel, arrived soon after from the same corner of the planet and slowed down her sister’s progress.
Nature surprises us every day. These mussels, by eating the plankton, have put many indigenous species in danger; however, they also created a favourable environment for other species. The mussels gather in close colonies that offer shelter and food to certain species. A little fish called a spotted goby takes advantage. It is an invasive species found from the Lake Ontario to the Ouelle River.
If the consequences of the arrival of the zebra mussels no longer make the headlines, we should not ignore them. The damages done in the Great Lakes to the water treatment plants and pipelines that supply the resident’s drinking water and to the nuclear energy plants is substantial. The cost of the damages runs to billions of dollars. In Québec, the city of Magog voted a budget of 1.2 million dollars to remove the zebra mussels from the water pipe of the filtration plant. Sorry to write that they will be back.
The zebra mussel, once established in a body of water, is entrenched. An article in La Presse reported attempts of eradication in Lake Massawippi. Teams of divers descend into the lake, knives in hand, to remove them. I have good reason to be skeptical with this attempt of removing these mussels that are able to reproduce at such a staggering rate. On the other hand, I have confidence that nature will, one day, find a solution.
When we have them in Lake Champlain the water is so nice and clear including the bottom. Haven’t any get into my lake water intake as have a filters at the end in the lake. It’s funny how they go in cycles as some years we have none and other years the shore line is full of them.