Like some kind of relic from a shipwreck or a suburban Atlantis, a discarded shopping cart encrusted with zebra mussels was intriguing enough that a man vacationing in Minnesota loaded the oddity onto the bed of his pick-up truck to take home to North Dakota.

And in doing so, broke the law.

The shopping-cart carter, North Dakota resident, Bruce Hinsverk, was cited for illegal possession or transport of a prohibited invasive species when two conservation officers with the Minnesota Department of Natural Resources (DNR) spotted the cart sitting in the truck. Hinsverk was fined $500.

"He thought it was unique to have a cart with mussels attached and that it would make a nice addition to his business," officer Jen Mueller told Fox 9. "So he placed it in his truck. He did not know it was illegal to transport invasive species."

Native to Eastern Europe and Western Russia, zebra mussels hopped a ride in the ballast water of freighters to the Great Lakes where they were discovered around 1988. They have spread throughout the Great Lakes, Mississippi, Ohio, Tennessee, and Hudson river basins.

And they are tenacious. They attach to aquatic plants, boats, nets, docks, swim platforms, boat lifts, (and shopping carts, evidently) and can be transported on any of these objects. Microscopic larvae also can stowaway in water left in bait buckets, bilges or any other water moved from an infested lake or river.

It's unclear how the shopping cart got from the lake to the dumpsters where it was found. At the time the officers placed the cart in DNR storage, they noted that some of the mussels were still alive. Was an unwitting massive spread of the menacing mollusks thwarted? It's hard to say, but strike one up for the DNR officers just in case.

Related invasive species stories on MNN:

Man fined for transporting mussel-covered shopping cart
A unique souvenir from Lake Superior lands a traveler in hot water.