Moss Ball

Mussel on a moss ball.

Despite a massive boat inspection program to prevent quagga and zebra mussels from populating Northwest rivers and streams, the tiny creatures have found another way to reach the region—through pet stores.

State officials in Washington, Oregon, Idaho and Montana have found zebra mussels tucked into balls of moss bound for home aquariums. Initial reports indicate the mussels have been making their way from pet stores to home aquariums throughout the country for at least two months.

The invasive mussels are now closer to becoming a huge problem for hydroelectric projects, irrigators, recreationists and salmon recovery advocates. The states are on a mission to rid stores of all "Betta Buddy Marimo Balls," convince aquarium supply stores to stop stocking them, and get stores and aquarium owners to kill any they find by either freezing or boiling them prior to disposal.

Without killing the mussels first, officials fear they could get into stormwater and survive until they reach a water body, where they may thrive. Zebra and quagga mussels quickly multiply once established, and can disrupt the food chain, clog pipes for drinking or irrigation water, roughen fish ladders, and cover beaches and the undersides of boats.

The Northwest is the last major region in the United States where the mussels have not established themselves. Estimates vary, but officials say it would cost roughly $500 million annually to control zebra or quagga mussels if they become established in the Pacific Northwest.

The U.S. Army Corps of Engineers has said an established invasive mussel population in the Columbia Basin could result in economic impacts to power infrastructure similar to the $3.1 billion spent from 1993 to 1999 in the Great Lakes region.

Justin Bush, executive coordinator of the Washington Invasive Species Council, told Water Power West that the Washington Department of Fish and Wildlife convened an incident command team to deal with the situation on March 2. "It seems like this might be a national problem," he said.

On March 3, the Oregon Department of Fish and Wildlife issued a news release reporting that the agency had been alerted that a Seattle Petco employee discovered a zebra mussel attached to one of the moss plants. An invasive species supervisor visited a store in Salem and also found viable zebra mussels inside the moss.

The Seattle employee reported the discovery to the U.S. Geological Survey, commenting, "Mussels were found in shipments of Marimo moss balls (an aquarium plant) that are sold at the pet store. I work in the aquatics department, and almost every shipment of these moss balls that I have unpacked for the past two months has had mussels nestled in the moss balls."

By March 4, WDFW officers had investigated the report, removed 56 Marimo moss balls from stores, and confirmed at least 12 zebra mussels present.

"Once alerted, several other states have reported the presence of both live and dead zebra mussels at other retailers," the WDFW news release said. The mussels were found at both Petco and PetSmart stores, which sell the product nationwide. Becky Bennett, WDFW spokeswoman, said at the moment, the agency has only found the mussels in the product sold as Betta Buddy, through the company Imagitarium, but is asking aquarium owners to check all Marimo balls. Anyone who has a question about whether to destroy their moss ball can take a picture of any suspicious area and submit it to the state for an expert to review.

The agency is also investigating the origins of the product, and contacted wholesale distributors in California and Florida, which stopped shipments.

The agency is asking anyone who has purchased a Marimo moss ball from any retailer to inspect it and safely dispose of it. Methods include placing the moss into a plastic bag and putting it in the freezer for at least 24 hours before putting it in the trash. The moss can also be boiled for at least one minute before disposal. The agency's news release includes instructions for cleaning aquariums and accessories that may be contaminated. The agency is also asking aquarium owners not to dispose of aquarium water in a household drain, and to report this or other suspected invasives.

Both Petco and PetSmart have pulled the product from their shelves across the country, and placed them in quarantine, the WDFW news release said. In a statement, Petco said it was working with regulatory agencies and determining proper handling and disposal of the moss balls that contain mussels. The company also stated they are "proactively contacting our customers to provide information and resources on how to responsibly collect and dispose of them at home if necessary."

WDFW Police Captain Eric Anderson said no single organization can solve the problem. "We are working in partnership with industry and every level of government to solve this as quickly as possible. This coordination is how we're successfully preventing these species from taking hold in Washington."

Bush noted that anything that moves can inadvertently transport an invasive species.

"Invasive plants can hitchhike on your boots, aquatic animals can attach to your boat or equipment, and problem species can also move by hitchhiking through commerce; as we see in this case," Bush said. "We all have a role to play to prevent and stop invasive species, and the most basic action is reporting anything that could be a problem and looks out of place. If you see something, say something because you could find the first hitchhiker and prevent millions, if not billions [of dollars of impact] to our economy and environment."

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K.C. Mehaffey covers fish issues for Clearing Up, and is editor of the NW Fishletter. She joined the NewsData writing team in February 2018. From lawsuits to scientific studies, she is enjoying the deep dive into the Columbia Basin's many fish topics.