08/16/2024
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DNR News
Aug. 15, 2024
Contact: Justin Bopp, 517-284-5830
ALERT: Invasive zebra mussels found in aquarium wholesale stock
Aquatic organism sellers and hobbyists urged to check stock immediately
The Michigan Department of Natural Resources is requesting pet stores, suppliers and hobbyists take immediate action in response to a new detection of Marimo moss balls infested with invasive zebra mussels.
What to do
zebra mussel in moss ball
INSPECT: Check aquarium moss balls for invasive zebra mussels.
DISPOSE: Remove and properly dispose of infested stock. Use the U.S. Fish and Wildlife Service protocol for proper disposal of infested moss balls, listed below and on the attached protocol document.
DECONTAMINATE: Use the U.S. Fish and Wildlife Service protocol for decontaminating aquarium water, aquariums and any equipment that has come into contact with zebra mussels. The information is also listed below.
REPORT: All discoveries of zebra mussels found in moss ball stock must be reported to the state. Contact Justin Bopp, DNR aquatic invasive species coordinator, at [email protected] or 517-284-5830. You can also use this contact information for assistance with inspection or proper disposal.
RESPOND: The DNR is requesting all aquatic organism sellers complete a short survey within the next two weeks to let us know if you have stocked moss balls within the past year. If you do carry moss balls, additional stocking and procurement information is requested. This information will only be used to gain a better understanding of the moss ball distribution system; moss balls are legal to stock and sell in Michigan. Take the survey here: https://arcg.is/110Tze.
INFORM CUSTOMERS: If moss balls are sold to customers, the DNR also asks that the information and decontamination procedures provided in this downloadable PDF be shared with customers in case they find zebra mussels at a later date.
Why take action?
Invasive zebra mussels are a restricted species in Michigan, which means it is unlawful to possess, introduce, import, sell or offer that species for sale as a live organism, except under certain circumstances. More information about zebra mussels is available at Michigan.gov/Invasives.
Marimo moss balls contaminated with invasive zebra mussels were found at an aquarium wholesaler in Renton, Washington, according to a press release issued on August 8, 2024 by the Washington Department of Fish and Wildlife. While this specific wholesaler does not ship to Michigan, the original importer, Florida Aquatic Nurseries, is known to distribute to Michigan retailers, and several importers may be sourcing materials from the same point of origin.
A similar incident occurred in 2021, and Michigan retailers, wholesalers and hobbyists were quick to respond by inspecting and reporting any zebra mussel detections to the DNR.
What are Marimo moss balls?
Marimo moss is a rare form of algae from Northern Europe and Asia, and Marimo moss balls are a popular aquarium plant used to generate oxygen and remove nitrates from tanks.
The moss balls may be sold as large balls or separated and repackaged in smaller containers at the retail level. The balls are sometimes packaged with individual betta fish in cups or containers.
Regularly inspect new stock
To prevent the introduction of invasive species, retailers, wholesalers and enthusiasts are encouraged to inspect and rinse new aquatic plants to rid them of seeds, plant fragments, snails, mollusks and fish. If you receive any stock that includes suspicious plants or animals, report your find at MISIN.MSU.edu.
Michigan State University Extension’s Reduce Invasive Pet and Plant Escapes (RIPPLE) program offers information and materials to help retailers and enthusiasts prevent the introduction or spread of aquatic invasive species. Learn more at CANR.MSU.edu/Invasive_Species/Ripple/.
U.S. Fish and Wildlife Service disposal and decontamination protocols
This information is also available as a downloadable PDF.
Moss balls or untreated water should not be disposed of in any location where they could reach local waterways.
DISPOSE
1. Destroy any contaminated moss balls using ONE of the following methods, ensuring that the disposal method you choose is in compliance with state laws and animal welfare regulations:
Place the moss ball into a sealable plastic bag and freeze for at least 24 hours, OR
Place the moss ball in boiling water for at least 1 full minute, OR
Submerge the moss ball in chlorine bleach, diluted to 1/3 cup of bleach1 per gallon of water, for at least 10 minutes, OR
Submerge the moss ball in undiluted white vinegar for at least 20 minutes.
2. Once Step 1 is complete, place the moss ball and any of its packaging in a sealed plastic bag and dispose in the trash.
3. If vinegar, boiling water, or bleach was used, the liquid can be disposed down a household drain – never down a storm drain, where it could enter and damage local waterways.
DECONTAMINATE
If the moss ball was placed in an aquarium, please take these additional steps to decontaminate your aquarium and accessories. If the moss ball was placed in a water garden, and fish or plants cannot be removed from the aquarium for treatment, please refer to the Potassium Chloride (KCl) Method below.
1. Collect any fish or other living organisms and place them in another container, with water from a separate, uncontaminated water source.
2. Remove water from the aquarium and sterilize the water by adding 1/3 cup bleach per gallon of water. Let the water sit for at least 10 minutes and then dispose the sterilized water down a household drain.
3. Decontaminate the aquarium and accessories using one of the following methods, in accordance with manufacturers’ recommendations:
Hot Water Method:
Pour water that is 120oF into aquarium, covering all accessories.
Allow to sit for a minimum of 5 minutes, ensuring that the water temperature is maintained.
Allow the water to cool, then dispose of treated water in a household drain.
Salt Water Method:
Make a saline solution using 1/2 cup of salt (NaCl) per gallon of water.
Soak aquarium, substrate, rocks, décor, and filter media in salt water solution for at least 24 hours.
Dispose of treated water in a household drain.
Rinse off all items prior to re-setting up the aquarium.
Bleach Disinfection Method:
Make a disinfection solution using 1/3 cup bleach per gallon of water.
Soak aquarium, substrate, rocks, décor, and filter media in bleach solution for at least 10 minutes.
Dispose of treated water in a household drain.
Rinse off all items prior to re-setting up aquarium.
4. Allow aquarium and accessories to dry for at least 15 minutes before refilling with water.
5. It is recommended that you perform a standard water exchange (~20%) within a week and continue to monitor the aquarium for any unusual or unexpected aquatic life. If needed, repeat steps 1-5.
Alternative Treatments
Potassium Chloride (KCl) Method: While this method is considered safe for most finfish and plants, it may not be safe for invertebrates. This treatment uses KCl, a sodium-free table salt substitute commonly sold at grocery and nutritional stores. The highest available purity of KCl should be used. “Half-Salt” products cannot be used.
Use the chart below to determine the amount of KCl needed based on the volume of water in the aquarium or water garden.
Remove a small volume of water (~1/2 gallon) into a separate container. Add the required amount of KCl and mix until it is dissolved.
Pour the KCl solution back into the water garden or aquarium and leave it for at least 14 days at a minimum temperature of 65 degrees Farenheit.
Water changes should be avoided during the treatment period. If it cannot be avoided, ensure that water removed is sterilized by adding 1/3 cup of bleach per gallon of water. Let the water sit for at least 10 minutes and then dispose the sterilized water down a household drain.
If water needs to be replenished due to evaporation, ensure that the volume of replacement water does not exceed the volume of water that evaporated. Replacement water should be from an uncontaminated source, warmed to a minimum of 65oF and pre-treated using KCl to ensure a constant concentration of KCl during the 14-day treatment.
Decontaminate any submerged accessories and equipment used to remove water or organisms from the aquarium or water garden using either the hot water, salt water, or bleach methods listed above.
Table for KCl dilution
1Use regular, unscented bleach. Check the label to ensure that the bleach is EPA-registered and has a concentration of at least 5% Sodium Hypochlorite. Bleach is corrosive, use with caution. Read and follow all product labels. Appropriate personal protective equipment should be worn to avoid personal injury when using chemicals.
