Freshwater mussels collected during a scientific sampling event on the Clinch River in Virginia. (Sarah Vogelsong / Virginia Mercury)
The Cumberland monkeyface, Pistol-grip and Rayed bean may be some of the most unsung heroes of Virginia’s waterways.
All three are types of freshwater mussels, one of the planet’s most unique and underappreciated creatures. But these species have also been vanishing from waterways in alarming numbers for decades. In Virginia, more freshwater mussels than any other species are listed as endangered by the U.S. Fish and Wildlife Service.
Scientists and other mussel advocates aren’t giving up hope, however. And thanks to new state funding, freshwater mussels could see their numbers grow stronger in the years to come.
This year, the General Assembly approved $400,000 to fund a statewide freshwater mussel restoration plan – a first in Virginia’s history. The Virginia Department of Wildlife Resources will receive the funds over the next two years to hire two additional staff members and plan strategies to restore dwindling populations.
Strategies can look like this summer’s release of the endangered James spinymussel into the main stem of the James River, where it hasn’t been seen for more than 50 years. Scientists worked for over 20 years to propagate, raise and release almost 1,300 mussels in an attempt to reestablish a native population in the river.
“That’s not something that happens every day that you’re able to reintroduce a species like that,” said Joe Wood, a senior scientist with the Chesapeake Bay Foundation who works closely with freshwater mussels. “It sort of speaks to the promise of what we can do. We have a concerted effort and that’s really without a ton of dedicated resources.”
New technologies and techniques for mussel propagation are helping efforts to restore even more species, said Brian Watson, Virginia’s chief malacologist, or mollusk scientist. There are currently three freshwater hatcheries in Virginia dedicated to restoring the organisms across the state.
One of those hatcheries, DWR’s Aquatic Wildlife Conservation Center located near Marion, has successfully produced 39 species of freshwater mussels, including 19 federally endangered and six state-listed species. The center has released over 150,000 juvenile mussels in the past 16 years into Virginia portions of the Clinch, Powell and Holston rivers.
The funding for the restoration plan is thanks in part to the surplus in this year’s state budget, said Sen. Creigh Deeds, D-Bath, who requested the funding in the budget. It’s a relatively small amount, but advocates say it’s a significant victory for freshwater mussels.
“The whole idea is just to get the Department of Wildlife Resources to have some people to work on the restoration, do some research and figure out how we can make sure these very vital organisms don’t go extinct,” Deeds said.
Decline of the ‘livers of the rivers’
Scientists estimate that 70% of the mussel fauna in the U.S. are in peril, while only 30% of Virginia’s 82 species are considered stable. The remainder are in decline, according to DWR.
Mussels, often called the “livers of the rivers,” are essential for maintaining clean waterways throughout the state and preserving a balanced ecosystem. A single one can filter up to 15 gallons of water per day, preventing nutrients and other harmful pollutants from flowing downstream, according to a report released last year by a Chesapeake Bay Program committee.
The report also estimates that 90% of the freshwater mussel population in the Chesapeake Bay has been lost due to a number of human and environmental factors.
Dams can disconnect fish from mussel populations that rely on them to carry their larvae. And while freshwater mussels are adept at filtering out pollutants, even they cannot survive in the most contaminated waters. Runoff from agriculture or developed lands can infiltrate waterways and prove fatal for the organism.
“Everything depends on clean water,” Deeds said. “From humans and other mammals, to reptiles, amphibians and vegetation.”
Challenges to restoration
Understanding how freshwater mussels reproduce is central to understanding why restoring populations is so challenging, Wood said. Unlike other animals that can actively search for a mate, mussels rely on fish to carry their fertilized eggs. It’s a very complex process that biologists are still learning to re-create outside of the mussels’ natural environment.
“Twenty to 30 years ago we weren’t even able to simulate that process,” Wood said. “Making baby mussels was not on the table in relatively recent history.”
But it can be difficult to determine what host fish each freshwater mussel species needs for propagation or what its historical range used to look like.
The $400,000 in the budget is more than enough to create the restoration plan, said Watson. The concern is what happens after the funding runs out and it’s time to implement it.
“That’s always the issue with doing conservation with any type of species, is usually we’re always short on resources,” Watson said. “In Virginia we have about 80 species of freshwater mussels and we’re just not going to be able to work with all of them.”
The department has to prioritize what mussels it will put its efforts into, which could lead to more rare species getting less attention.
In Virginia we have about 80 species of freshwater mussels and we’re just not going to be able to work with all of them.
– Virginia chief malacologist Brian Watson
“They may be so rare that just biologically it’s difficult to restore them,” Watson said. “You put a lot of work into them kind of at the expense of other species that you might be able to work with and actually achieve some positive results.”
That was the case with the green-blossom pearly mussel, which was officially declared extinct in Virginia last fall.
Wood said the restoration plan will be helpful whether or not additional resources are given after the funding runs out. That’s because it will allow partner agencies and organizations to work with DWR to come up with solutions that may not necessarily involve more expensive restoration methods.
Planting natural forest buffers alongside waterways, for example, can help reduce sediment and other pollutants that would otherwise run off into mussel habitats and threaten species’ longevity. Working with private landowners to do conservation projects like fencing out livestock from waterways helps improve water quality as well.
“Every bit of the natural ecosystem is important to our existence if we are to exist as a civilized people,” Deeds said. “We need to recognize that the things that are natural that exist in nature all have a purpose, and if we are to have a balance in our lives, in our environment, in our communities, we need to make sure that all those natural organisms are able to exist and to maintain the equilibrium.”
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