WDA Issues Quarantine Order for Marimo Balls

CHEYENNE, Wyo. (Release) - The Wyoming Department of Agriculture has issued a quarantine against the importation of Marimo balls as part of an effort to curb the presence of the highly invasive zebra mussels recently identified in these products in Wyoming and across the country.

As part of this order, no person, firm, partnership, corporation, or any other entity shall import or transport Marimo balls into the State of Wyoming. Marimo balls (a type of algae also known as Cladophora balls, moss balls, lake balls, or Cladoohora aegagropila) that were infested with zebra mussels were recently detected by Game and Fish personnel in several Wyoming pet stores. These products are sold at many aquarium and pet supply stores and are popular tank decorations made of green filamentous algae used to oxygenate the water.

Zebra mussels are an aquatic invasive species that can cause damage to natural resources and water systems and cost U.S. taxpayers more than $1 billion in damage annually. Once they become established in reservoirs, lakes, or other water systems, they remove nutrients from water, clog pipes and waterways, and can damage property. Zebra mussels are striped, less than 2-inches in size, attach to any hard surfaces, and are extremely resistant to cold temperatures and many chemicals.

“It’s important to issue this quarantine in order to do everything we can to stop these infested products from coming into the state,” said Doug Miyamoto, Director of the Wyoming Department of Agriculture. “These zebra mussels are an invasive species that, once they establish themselves in a water body or system, are impossible to remove and could have significant and costly impacts for Wyoming.”

If you are in possession of any of these Marimo balls, take the following actions to safely dispose of the products:

1. Remove any pets from the water and tank.

2. Remove the moss ball, other plants and any water from the aquarium and put them into a heat-safe pot. Do not dispose of any water down the drain or toilet.

3. Inspect the moss ball and tank for zebra mussels and if you find any, contact your local Game and Fish regional office or local warden.

4. Boil the moss balls, plants and any water it’s been in contact with for at least five minutes.

5. Dispose of the moss ball and other plants in trash.

6. Pour out the boiled water on a semi-permeable surface. That could be a houseplant or outside – like grass or soil – that is not located near standing water or a storm drain.

Do not flush the moss ball or pour aquarium water down any drains, toilets, or into nearby water sources like a local pond or creek. These actions could spread zebra mussels throughout the water system.

For a copy of the quarantine order, visit agriculture.wy.gov. For more information on zebra mussels including images and WGFD contacts, visit the Wyoming Game and Fish website at https://wgfd.wyo.gov/Get-Involved/AIS-moss-balls