The state’s Fisheries Division is getting a new hire this month: a full-time malacologist. That’s a biologist who studies mollusks, including mussels and clams.
And it’s the first time Michigan’s Department of Natural Resources will have a scientist entirely devoted to studying the creatures.
Lucas Nathan, aquatic invasive species coordinator for the DNR’s Fisheries Division, says the new biologist’s arrival will also kickstart a two-year mussel project.
The malacologist and the mussel project will tackle three main problems. The first is centralizing mussel data collected across the state.
“We have a lot of folks working on native mussel species — where they’re at and how they’re doing,” said Nathan. “And then we have information about where invasive [mussels] have been found.”
But with such big, disparate datasets, Nathan says the two still haven’t been merged to create a clear image of where invasive and native mussels are overlapping.
That’s important because native mussels are crucial to maintaining healthy freshwater ecosystems. They often live for multiple decades, filtering and purifying water and providing an important food source.
But they’re increasingly outcompeted by invasive zebra and Quagga mussels.
North America is home to the most diverse range of freshwater mussels on the planet. Michigan alone has about 45 different species of freshwater mussels, but 32 of those are considered at-risk.
Nathan says that’s due to a combination of factors: Habitat loss through things like dredging, pollution and damming, a decline in native fish species and the arrival of invasive mussels.
He says once the two datasets on invasive and native mussels are merged, the project can turn toward prioritizing certain bodies of water.
“Where do we have places where we have native mussel species that we don’t have invasives yet? Those are the places we want to try to prioritize for preventing invasive mussels from being introduced,” Nathan said.
He says the state has a pretty good understanding of where mussels are in rivers and the Great Lakes. But inland lakes lack data.
“Our knowledge of native mussel species in some of those systems is definitely lagging behind. There's still instances where we're finding threatened or endangered species … Sometimes they're right under our nose, and we just haven't found them yet,” Nathan said.
Nathan says the third problem the new malacologist and mussel project will focus on is prevention.
Most efforts to slow the spread of invasives have been through education and communication, like signs on boat launches encouraging anglers to clean gear.
Nathan says this project will test another approach that biologists have been wondering about: physically scraping invasive mussels off of native mussels.
He says preliminary research shows a higher survival rate for mussels that are cleaned off. But there are still a lot of questions.
“Do we need to go out there every day and scrape these things off? Do we need to go out once a year, once every five years? We just don’t know those things yet,” Nathan said. “This is really just a first attempt at thinking about what this could look like from an experimental perspective.”
He says the division currently has grant money to fund two years of the malacologist position and the mussel project. Research will begin this winter alongside partners like Central Michigan University.
