Invasive mollusks hitch ride to Alaska on aquarium algae

Invasive species managers consider zebra mussels to be one of the most detrimental invasive species in North America. (Alaska Department of Fish and Game)

There’s a new species on Alaska’s most wanted list.

Invasive Zebra mussels have made their way up north from the Lower 48, hitching rides on aquarium moss balls to pet stores.

Biologists in Alaska and more than 30 other states are concerned. For a creature the size of a fingernail, zebra mussels pack a lot of punch.

Maura Schumacher is the invasive species specialist for the Kenai Watershed Forum. She said zebra mussels, named for their striped shells, can thrive in both rivers and lakes.

“They are filter feeders, so basically they pull in water through their systems and they pull out nutrients,” she said. “And the waste that they are producing is highly acidic and drops the oxygen levels in water systems.”

That creates an inhospitable environment for the other plants and animals living there.

Zebra mussels are native to Eastern Europe and likely came over to the U.S. on ships in the 1980s. They infested all five Great Lakes and traveled to connected freshwater systems through canals.

It’s still a mystery how they glommed onto moss balls — small clumps of green algae that help filter water in household aquariums. But that’s allowed them to spread across the country.

“Because these moss balls are being sold by these major pet suppliers, they’re getting shipped to places like Alaska,” Schumacher said. “Which normally — it’s not impossible, but it’s very difficult for a zebra mussel to travel from the Great Lakes region to Alaska.”

The mussels could infiltrate local ecosystems if people dump their aquariums into lakes and rivers. They can wreak havoc on personal property, too.

“Some of the other impacts that they have is that they reproduce so quickly, they can clog storm drains,” she said. “They can cause incredible damage to boats and other recreational equipment. They just clog up any space available.”

State and federal agencies are coordinating to warn people who may have purchased moss balls. Major pet stores like Petco have also put out advisories asking customers to toss their moss balls.

“If you have recently purchased these moss balls, destroy them immediately,” Schumacher said.

She said acting on the defensive is important. Alaska has previously been able to intercept boats carrying zebra mussels.

“And when you’re on the offensive, like they are in the midwest and the Great Lakes region, it’s costing those states and economies millions and millions of dollars on a yearly basis,” she said.

The U.S. Fish and Wildlife Service is asking people to destroy their moss balls. They’ve released official guidelines for doing so.

Moss balls can either be freezed, boiled or bleached and then tossed in the trash in a sealed plastic bag. Aquariums that contained moss balls should be drained and cleaned.

The agency is also asking people to report zebra mussels they find. You can do that here.

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