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How An International Investigation By The Idaho Ag Department May Have Saved The State $1 Billion

Idaho State Department of Agriculture
Zebra mussels, smaller than a grain of rice, tried to invade the state by piggybacking on a popular aquarium product.

No bigger than a grain of rice, zebra mussels are deadly intruders that traveled from the Ukraine to Idaho, threatening to poison the state’s water supply. But the state Ag Department tracked down these tiny, invasive creatures before they could target Idaho’s waterways.



It all started in Seattle. A worker at a pet store took a closer look at the moss balls being sold there and found invasive zebra mussels. When the Idaho Department of Agriculture’s Nic Zurfluh found out, his Invasive Species Program went to work testing moss balls all over the state.


“Our response was immediate.”

Credit Idaho State Department of Agriculture
Idaho State Department of Agriculture
The velvety moss balls grow as big as five inches while the tiny zebra mussels can be as small as a grain of rice.

The Marimo moss balls aren’t moss at all, but a rare round decorative algae popular with aquarium enthusiasts. But where were they coming from?

“These moss balls are originating and being harvested from the Ukraine and shipped in through Thailand and into a port in Los Angeles," Zurfluh said. 

He quickly discovered Idaho was not alone. Moss balls carrying the tiny invasive mussels were soon found in other states.

"From Alaska to Florida, up to Vermont and Maine and back down to California, essentially everywhere in-between."

However, the piggybacking aquatic species was not easy to find.

“And if you could imagine a zebra mussel about the size of a grain of rice attached to that moss ball, that was the size class we were finding during our inspections,” said Zurfluh.

His investigators tracked the distinctively striped mussels to 12 Petcos and six Petsmarts in Idaho. 

“We were able to pull contaminated product off the shelf within 24 hours," he said.

Then they worked with the chain stores to stop any more coming into the state. They told aquarium owners to kill any moss balls and, most importantly, not to dump the aquarium water in any natural waterbody.

Why all the fuss? For 12 years, Idaho has been spending millions of dollars to keep zebra and quagga mussels out of the state. The Ag Department has checkpoints along Idaho’s borders to inspect every boat or watercraft coming in.


Last year, these checkpoints inspected over 135,000 watercraft and found 35 boats infested with mussells.


Nine years ago, the ISDA looked at how much it would cost if the mussels got in and clogged up hydropower dams, irrigation systems, drinking water facilities, the boating and fishing industry, even golf courses. At that time, the estimate was just shy of $1 billion.

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As Senior Producer of our live daily talk show Idaho Matters, I’m able to indulge my love of storytelling and share all kinds of information (I was probably a Town Crier in a past life!). My career has allowed me to learn something new everyday and to share that knowledge with all my friends on the radio.

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