Invasive species specialists in the Maritimes are calling on aquarium retailers and hobbyists to check for the highly-invasive zebra mussel that’s been discovered hitching a ride on moss balls.
Marimo moss balls are a type of algae that is often used as decoration in aquariums.
A Seattle pet store first reported the zebra mussel early last week. Since then, the small freshwater mussels have been discovered on moss balls in Canada.
“Zebra mussels have been confirmed in Alberta, Saskatchewan, British Columbia, and Maine, so they are a very real threat to the Maritimes if the moss balls were distributed here as well,” Kristen Noel, the project coordinator with the Nova scotia Invasive Species Council, told Global News.
“Even if they do not make it to Nova Scotia via the moss balls, there are many other pathways they could use. If they were to arrive in any of the Maritime provinces, they could easily be spread here by hitching a ride on boats, boat trailers, ballast water tanks, etc.”
Zebra mussels may look harmless and inconspicuous — they only get about as large as a thumbnail — but they are considered one of the worst aquatic invasive species around.
Noel says they multiply rapidly and can survive out of the water for a long period of time. Once they are allowed to spread, they out-compete native species for space and food, such as plankton.
“Zebra mussels are a huge threat to native mussel species, such as the brook floater, which is a Species At Risk that is present in both Nova Scotia and New Brunswick,” said Noel.
She adds removing plankton will also increase the amount of sunlight in the water, which can cause warmer temperatures and lead to toxic algal blooms.
Large colonies of the zebra mussels can also affect important fish spawning sites.
As if the ecological impacts weren’t bad enough, the mussels can also damage boats, pipes and water treatment facilities by attaching itself to them.
So, what can aquarium owners do?
The invasive species councils of Nova Scotia, New Brunswick and PEI are reminding people to inspect their moss balls for tiny hard shells. They can be very small, though, and the mussels could even be in the larval stage, and therefore invisible to the naked eye.
That’s why the councils are encouraging people who recently purchased moss balls to return them or dispose of them responsibly.
Methods include freezing the balls in a plastic bag for at least 24 hours or putting the moss balls in boiling water for a full minute, and then throwing them into the trash in a sealed plastic bag.
People are reminded not to flush the moss balls down the toilet or put them in compost.
If the balls have already been used in an aquarium, the tank and other decorations should be washed in a solution of chlorine bleach and water, or boiling water.
If anyone suspects they’ve discovered a zebra mussel, they’re asked to report it to the Department of Fisheries and Oceans.