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Surveying Salamanders in Hopes of Finding an Imperiled Mussel

This story was first published on April 12, 2019.

This story is part of our series, Wild Pennsylvania. Check out all of our stories here

9/15/2023 Update: The U.S. Fish and Wildlife Service has proposed listing the salamander mussel as endangered under the Endangered Species Act. In Pennsylvania, the mussel has been designated as endangered since 2010. According to Nevin Welte, freshwater mussel biologist with the Pa. Fish and Boat Commission, federal protection would provide more resources and attention to the species in Pennsylvania. “The Fish and Boat Commission and all the partners would work with [U.S.] Fish and Wildlife to try to continue our efforts to get this species recovered in the state of Pennsylvania.” Public comments are being accepted until October 23.

Freshwater mussels once numbered in the millions in the Ohio River. But the industrialization of Pittsburgh’s rivers — coal mines, steel mills and dams — harmed many species of mussels. Some disappeared, unable to survive in the muddy, polluted waters. 

Now, researchers are surveying the rivers to see if one species of salamander — the mudpuppy — is bouncing back in hopes that an endangered mussel, which needs the salamanders to survive, can make a comeback, too.

LISTEN: “Surveying Salamanders in Hopes of Finding an Endangered Mussel”

Salamander mussels have been on Pennsylvania’s endangered species list since 2010, when salty pollutants from a Consol Energy mine discharged into Dunkard Creek, along the West Virginia border, killing much of the aquatic life there, include some 15,000 salamander mussels.

And in a double whammy for salamander mussels in particular, 6,000 mudpuppy salamanders also died. 

Photo by Lisie Kitchell, WDNR

The salamander mussel needs the mudpuppy to fulfill its life cycle. Mussel larvae are found on the mudpuppy’s frilly red gills. They don’t harm the mudpuppies, and drop off after two or three weeks to live inthe sediment. But with no mudpuppies, there’s no way for the salamander mussels to survive.

According to Fish and Boat Commission mussel biologist Nevin Welte, mussels are an important part of the river ecosystem.

“They just sit down there and filter water, and serve as habitat for bugs, and also food for things like fish and muskrats, and otters,” explains Welte. “They’re a pretty important part of the food chain.”

Welte works with Ryan Miller, a zoologist with the Western Pennsylvania Conservancy, to survey parts of the Ohio and Allegheny Rivers for both mudpuppies and salamander mussels. It’s a project of the Pennsylvania Natural Heritage Program and funded by the Department of Conservation and Natural Resources.

Surveying the Allegheny

On this early April morning, Welte and Miller are out on the Allegheny River about twenty miles northeast of Pittsburgh in a small research boat, checking a hundred traps for mudpuppies, with the hope of also finding Salamander mussel larvae attached to them.

“Our only known locations right now are actually in this pool [of the river] that we’re in, and a couple of others,” Welte said of the mussels. “That’s pretty much it for the Allegheny.”

Miller slows down the boat as it approaches a small orange buoy not far from the shoreline. Welte reaches a long pole into the water, and with a hook on the end of it, grabs the buoy and pulls the rope. A cement block emerges — the anchor.

As Welte keeps pulling, cylindrical mesh, metal traps emerge from the water one by one, each bigger than a football.

 “There’s one there!” Welte exclaimed. 

After a few more empty traps, they find another one.  Now it’s time to get to work. Miller lifts out one of the brown, slimy mudpuppies.

“When you pull them out of the water, they get pretty feisty, so I try not to handle them with my hands too much,” he said.

Miller flips the salamander over and discovers it’s a female. He measures its length in a special device that looks like half of a pvc pipe. The salamander is just over 10 inches. He weighs it and takes its picture.

Next, he runs his thumb over the mudpuppy’s frilly red gills to check for salamander mussels. He sees white spots on them, which is what you’d expect from the mussel larvae.

“But I don’t think it’s mussels, I think it’s just extra slime,” he said. The mussel larvae would feel sandy, he explained.

Miller examines the second mudpuppy, releases both back into the water.

Historic Pollution Wiped Out Millions of Mussels

While there isn’t much historical data on the number of mudpuppies in Pittsburgh’s rivers, it’s known that millions of freshwater mussels once burrowed in the bottom of the Ohio River, filtering billions of gallons of water.

“This is the last living freshwater mussel in the Ohio River in Allegheny County”

In the early 1900s, biologist Arnold Ortmann surveyed the region for freshwater mussels, when coal and steel pollution was largely unregulated.

“As it was actually happening, as everything was dying off, he was walking the banks and doing collections, as the dead mussels were washing up on shore,” Miller said.

“There’s a couple of sad records that he’s written,” Welte continues talking about Ortmann, “There was one round hickory nut (mussel) that he found at Neville Island, and he said, ‘This is the last living freshwater mussel in the Ohio River in Allegheny County.'” 

But Ortmann never found Salamander mussels.

“The first record that we have of Salamander mussels in Pennsylvania was actually from the 1960s,” Welte said, and that was in the Allegheny River.

This summer, Miller plans to survey for adult Salamander mussels, by scuba diving, and checking by hand under rocks and debris for the bivalves.

Mudpuppy Recovery

But for the Salamander mussels to bounce back in this region, they need mudpuppies.

“We trapped at Dunkard Creek for mudpuppies over the past couple of seasons too,” Welte said, “And we’ve only found one individual.”

Miller said surveys like the one they’re doing in this part of the Allegheny give him reason for hope.

“The fact that we’re catching them in the rivers, now and in these numbers, yeah, they’re doing ok,” he said. “Any large scale pollution event would essentially kill them, but right now they’re doing ok.”

If this round of surveying finds enough mudpuppies, Welte said researchers are considering relocating some of them to Dunkard Creek. They hope to repopulate not only the salamanders there, but also the mussels that need them to survive.