GIMLI — He has spent his entire life fishing on Lake Winnnipeg and knows it well. But on one of his last rides of the season it’s what Chris Kristjanson couldn’t see that was worrying him.
Zebra Mussels potentially multiplying by the millions on the lake floor below.
“That’s the scary part, I don’t think anyone realizes how bad this can look,” Kristjanson said.
Zebra mussels were first found in Manitoba in 2013. By the fall of 2015, boaters on Lake Winnipeg had found them clinging to their motors and hulls.
While the growth of the invasive species and it’s impact on the lake all depends on the makeup of each body of water, it’s possible they multiply into the trillions in only a couple of years.
Thomas Jones, a specialist with the department of natural resources in Minnesota, shared video of what they uncovered over the last decade in Mille Lac, where in 2005 divers found just a handful of zebra mussels.
RAW: Recorded dive in Mille Lac in Minnesota shows zebra mussels covering the lake bottom
After only one year they had multiplied to 323,000, the following 9.6 million, the year after that 284 million. By 2012, when their growth rate started to slow, an estimated 2.3 trillion zebra mussels had carpeted the lake floor.
“It was very surprising,” Jones said.
In the first few years, Jones estimates the population increased annually by a factor of almost 30. By the time they were in the billions, the growth rate had slowed due to “crowding”, and has since tapered off. But that has still left them with a population in the trillions.
The more there are, he says the greater the chance they could spread.
“One of the problems is that as they become very abundant they begin to live on vegetation as well as rocks. And it’s that vegetation that can very easily be picked up on the trailer,” Jones said.
Each lake reacts differently and Jones says their still monitoring the potential impact on Mille Lac. The prevailing concern remains the zebra mussel’s ability to filter the water, essentially consuming the food fish rely.
It’s one reason why Manitoba has made it law to clean, drain and dry any boat before moving it to another body of water. The province has plans to step up inspections of those boats it still hasn’t decided whether it will create any permanent inspection sites on any major highways in and out or high risk lakes and areas.
“We can’t be chasing each and every boat in the province around,” Conservation Minister Tom Nevakshonoff said. “We have to engage the people of Manitoba themselves.”
This is the first of a three story series focused on zebra mussels and the damage they can do