Parasites, genetic modification, could help mussel control

One of the leading experts on zebra and quagga mussels said he’s working on two methods that could ultimately control the invasive shellfish, but it could take years to develop them and get government approval.

Dan Molloy, with the State University of New York in Albany and with SUNY Buffalo State said he’s optimistic a biological control can be found.

Molloy has been studying them since 1990, about a year after the mussels were first detected in the Erie Canal in New York. A native of eastern Europe, the mussels were first discovered in the Great Lakes in 1988, likely brought over in the ballast of ships. Since then they have wreaked havoc with ecosystems in the U.S. They can reproduce by the millions and their shells clog intake pipes and other underwater structures, costing millions to control every year.

Now there’s strong evidence they’re in Montana in the Tiber and Canyon Ferry Reservoirs.

Molloy said in a telephone interview that he’s working on finding a natural parasite that would kill the mussels en masse without harming other aquatic organisms. He’s been searching for a parasite in a cousin of the zebra and quagga mussels that they haven’t been exposed to. If he can find one — and he believes he can, it would all but wipe out the creatures.

Molloy said he’s also working on a genetic solution as well. By tinkering with the genes of captive mussels, he said researchers can select a trait that would create a mussel that only produces male offspring. Mussels produce millions of young and over time, the mussels that have the genetic code to only reproduce as males would take over the population if they were released in wild populations.

As the males dominate, the population would no longer be able to reproduce and would eventually die out.

But both of those methods require stringent testing to make sure they’re safe, Molloy noted and would take years to develop.

Molloy has already developed a bacteria control for mussels. The method works, but only in contained areas, he noted. Treating a reservoir the size of Tiber or Canyon Ferry would be cost prohibitive and wouldn’t be 100 percent effective.

Still, Molloy was encouraged by Montana’s response to the outbreak.

“They’ve taken some good first steps,” he said.

He noted that Gov. Steve Bullock’s response was “pretty powerful.”

He also agreed that closing the water bodies to boats was the way to go.

“The big threat is boats,” he said.

But he didn’t hold much hope for the future. He said the spread of mussels is all but inevitable, but he also supports strong control measures as well.

That gives researchers time, hopefully, to find a solution. He noted it took nearly 20 years for his bacteria treatment to gain government approval and sufficient funding to come to fruition.