DULUTH -- Government agencies and invasive species programs across the country are urging stores to remove Marimo ball moss plants from sale after they were discovered to harbor a destructive invasive pest: tiny zebra mussels, which were found in imported aquarium plants and are sold in pet, nursery and home décor stores.

Consumers are urged not to purchase this product and -- if they have any at home -- to safely dispose of them by freezing or dunking in hot water, salt water or bleach. Once treated, balls can be placed in a sealed plastic bag and thrown in the trash.

If balls were placed in an aquarium or terrarium, it is a good idea to treat the tank, pump and accessories after removing fish, animals and plants, a release said.

“Large pet stores including PETCO and PetSmart have been extremely cooperative,” Doug Jensen, University of Minnesota Sea Grant Program’s Aquatic Invasive Species program coordinator, said in the release. “They have removed Marimo balls from their shelves and sanitized their tanks.”

In the past, Minnesota hobbyists have mistakenly released many aquarium plants and animals into the wild, and Jensen says releasing Marimo balls would be very destructive.

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Locally, the Duluth Cooperative Invasive Species Management Area (CISMA) is working with Jensen to get the message out to smaller retailers and hobbyists.

“Only a few Northland waters are infested with zebra mussels and we want to keep it that way,” Lori Seele, a CISMA coordinator, said in the release.

Zebra mussels, and their relatives quagga mussels, can quickly take over once they get into lakes and rivers. These invasive mussels can clog drinking water intakes and foul boat hulls, motors, docks and lifts. They disrupt the food chain and slow the growth of young walleye, making them vulnerable to predation and poor winter survival, according to a recent study by the University of Minnesota Aquatic Invasive Species Center.

If you see zebra mussels attached to moss balls, report it to the federal Nonindigenous Aquatic Species database at https://nas.er.usgs.gov.

Further guidance for zebra mussel disposal can be found at www.fws.gov/fisheries/ANS/zebra-mussel-disposal.html.