The invasive zebra mussel could yet get into Saskatchewan waters, a risk that is of concern to researchers.

Zebra mussels reproduce quickly and can damage ecosystems if unchecked.

"We found that the western provinces, including Saskatchewan, were at very high risk for invasion and that's because the lakes in southern Saskatchewan and Alberta have fairly high calcium levels," Scott Higgins, a research scientist with the International Institute for Sustainable Development's Experimental Lakes Area, said.

An single zebra mussel is only the size of a fingernail, but they can amass by the thousands and cover entire lake bottoms if conditions are right.

"It's the poster child of invasive species," Higgins said, noting they can colonize any hard surface — including other mussels. Zebra mussels also cause damage to items in the water, clogging filters for water systems and ruining boats.

Higgins has studied the zebra mussel for several years. Research shows the species was first noted in Canada in 1986 (in the Great Lakes) and advanced as far west as Lake Winnipeg and south to the Gulf of Mexico. The species has many natural predators in its native waters of Europe, but none in North America.

Higgins said the risk in Saskatchewan relates to how the zebra mussel could advance its territory by attaching to boats.

Governments have stepped up measures, such as boat inspections, to reduce the risk.