Chinese mystery snail makes itself at home in Alta. lake

Don’t let it loose.

Alberta Environment and Parks asks people to heed that demand as it fights to keep invasive species from affecting the province’s natural ecosystems.

The directive came too late for Lake McGregor, located in southern Alberta east of Vulcan.

Now the Chinese mystery snail has staked out a claim along a portion of the lake and its shore.

How the snail came to enter and proliferate in the lake will likely remain a mystery because numbers indicate it has likely been quietly reproducing for several years, said Nicole Kimmel, the aquatic invasive species specialist with Alberta Environment and Parks.

However, the alert about the snail, which is on Alberta’s list of prohibited species, only came in October 2019. At that time Patrick Hanington, a University of Alberta professor, contacted Alberta Environment to note a student had given him a snail found in Lake McGregor that he suspected was the Chinese mystery snail.

The department quickly obtained more samples from the lake and confirmed the species identity.

“We didn’t have to look very far before we started finding the Chinese mystery snails. Tons of shells in windrows along the shores … I would say thousands that we were easily able to find,” Kimmel said during an online meeting of the Alberta Invasive Species Council.

The fresh-water snails are about six centimetres high and about five cm wide, and are somewhat unique in having a “trap door” they can close to withstand cold, drought or chemical treatments.

“If you saw it, I’m pretty sure it would catch your eye and you would notice it as compared to our native snails,” said Kimmel.

The invasive species competes with native snails for food and habitat, can clog water systems and could be a host for parasites that affect other species. They can live out of water for up to four weeks.

Contrary to the snail reputation for being slow, Chinese mystery snails are fast at reproduction. Kimmel said a live snail she captured popped out two baby snails overnight and later birthed another 13 within days. Adults can give birth to more than 160 in a lifetime.

Her team surveyed the lake to gauge the spread of the snails and it does not appear to have spread beyond Lake McGregor, which is part of southern Alberta’s irrigation system.

However, large numbers make eradication unlikely so Alberta Environment plans a control strategy expected to involve a ministerial order requiring people to clean, drain and dry their boats when leaving the lake.

That order has not yet been made, nor has funding been approved for a mobile trailer that would help boaters do the necessary cleaning and drying.

Signs at the lake are also expected to help public awareness and encourage people not to spread the snails further.

“Hopefully with research, education and clean, drain, dry, we can move to containment,” said Kimmel.

Anyone sighting Chinese mystery snails for sale or in other Alberta waters is encouraged to call 855-336-BOAT (2628) to report it.

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