WA warning issued after invasive mussels found in aquarium decorati

The Washington State Department of Agriculture and the Washington State Invasive Species Council have issued a warning to consumers with aquariums and anyone who has purchased certain moss products.

Invasive zebra or quagga mussels found in moss balls

Zebra and quagga mussels are fast-growing invasive species that authorities in Idaho and Washington are trying to eradicate. If left unchecked, these mollusks can clog nearly any water system, including drinking water, irrigation, sewage, and others. They cling to solid objects and pile up on top of each other, creating massive plugs and blockages.

On August 5, Washington authorities were notified by a Renton aquarium store that they had received a shipment of contaminated decorative Marimo moss balls, commonly used as decorations in aquariums and other fish tanks. The store suspected the balls contained dangerous shells.

According to the Ministry of Agriculture:

“Laboratory testing confirmed that the mussels were zebra mussels (Dreisena polymorpha), an invasive aquatic species banned in Washington that, if established in local waters, could cause significant damage to infrastructure and the environment. Zebra mussels and a close relative, the quagga mussel, are not known to occur in Washington.”

“We’re asking anyone who has purchased Marimo moss balls from a retailer in the last year to examine the moss balls and take steps to rid their aquarium or water garden of invasive zebra mussels,” said Justin Bush, aquatic invasive species policy coordinator. “Anything that moves can transmit invasive species; problematic plant seeds can travel on your boots, aquatic animals can attach themselves to your boat or equipment, and harmful species can also move through commerce, as we’re seeing in this case.”

It is estimated that if zebra or quagga mussels were to be introduced into ecosystems on a large scale, the cost to the state each year for treatment and eradication would be more than $100.