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http://www.news-leader.com/apps/pbcs.dll/article?AID=/20061013/NEWS01/610130404
Making room for mussels
Biologists study, move mussels to keep them alive.
Mike Penprase
Creatures that many people taking float trips down Ozarks streams might mistake for rocks are much more than that ? they're freshwater mussels, which hold potential for cleaning polluted streams.
Missouri Department of Conservation biologist Steve McMurray said a five-year safety inspection of Pomme de Terre Dam --which will requires stopping water releases --means mussels could be marooned and die.
"Our major concern is that the de-watering process downstream is going to leave a lot of mussel beds high and dry," he said. "They can kind of close up their shells and shut down for a while, but after a while they'll be affected."
McMurray and other freshwater mussel experts led an effort Thursday to rescue Missouri bivalves from a dried-out Pomme de Terre River. It was a chance not only to save them, but to study them.
And there's a lot to study when it comes to Missouri mussels.
There are not only a lot of species ? at least 67 in the state ? these mussels are also considered the most threatened aquatic creature because of habitat degradation as well as competition from fast-breeding Asian clams and zebra mussels, he said.
McMurray said there are at least 20 different mussel species in Pomme de Terre, with four listed as species of concern in Missouri and one as threatened. With water in the river below the dam expected to be low for a week, mussels sitting on exposed areas of the riverbed could not survive, the mussel expert ? properly known as a malacologist ? said.
The mussel rescue effort amounts to flagging mussels so their locations can be mapped, measuring and marking some to find again later and finding deeper pools where they could be deposited.
While rarer species would typically be given special treatment to make sure their new homes were suitable, the lack of a lot of manpower ? mid-week is a tough time to find volunteers ? meant more common mussels were tossed back into the water, McMurray said.
"I imagine by the end of the day when we're nice and cold, we'll just be tossing them back in," he said.
But the session provided some learning opportunities.
Not only did the researchers find several species, they had time to show off their favorite creatures. The names of mussels, many of which were created by 19th-century mussel harvesters, include plain pocketbook, fat mucket, black sandshell and deer toe.
At one point, MSU biologist and malacologist Chris Barnhart stood over a mussel and shot video of it displaying a waving "lure" that's part of its reproductive cycle.
Mussels need to find fish hosts for their larvae that hitch rides on a fish's gills until they grow large enough to fall off.
The "lure" that mimics a minnow is used to attract fish such as bass, Barnhart explained to MSU sophomore and Stream Team volunteer Shawn Wring.
"She can make blow it up like a balloon; it's like a little fish," Barnhart said while prying open a crack in the mussel's two shells. "Inside, there's probably a cool million baby mussels."
Because building a cofferdam below the dam outlet took longer than expected, the rescue effort shifted further downstream to the north end of the camping area below the dam.
It didn't take long to find several beds with a variety of mussels.
Picking a plain pocketbook that had a light green shell with radiating darker green bands from a red plastic bucket, the MSU professor said there's nothing plain about some mussels. He works with the Conservation Department to propagate native mussels.
"One of these is sort of gem quality," he said. "People don't think of freshwater mussels as being pretty, but they're kind of like Easter eggs."
And if a theory that he has about what mussels eat proves to be correct, this creature that is harvested for its shell ? which is used to create cultured pearls and, for some, jewelry ? could play a much bigger role for humans.
What mussels eat largely remains unknown. But Barnhart said he suspects mussels that can pump up to 100 gallons of water a day through their systems might eat bacteria.
If that's so, mussels could be used as natural water filters, he said.
"They could be removing E. coli from the water and other human pathogens," he said.
If that's the case, there could be more emphasis on making sure mussel populations remain healthy, he said.
Although much of the concern about declining mussel populations involves habitat degradation and competition from non-natives species, there's also concern populations are being pressured by illegal harvesting.
Commercial mussel harvesting is allowed in Missouri, but the Conservation Department hasn't issued a license in a decade, McMurray said.
But the experts said that based on poaching arrests in the Bootheel and the discovery of a rare specie in bags in the Sac River, it's likely Missouri mussels are being sold outside the state, he said.
As for interest in eating freshwater mussels, McMurray said he doubts there's much demand.
He's talked to only one person who enjoys eating freshwater mussels, he said.
The reason is simple, McMurray and Barnhart explained: Compared to saltwater mussels suh as clams, freshwater mussels are considerably more active, using a fleshy appendage known as a foot to move around, McMurray said.
"These guys have muscles in their feet," he said of freshwater mussels.
"The upshot is, they're tough as shoe leather," Barnhart said.
Making room for mussels
Biologists study, move mussels to keep them alive.
Mike Penprase
Creatures that many people taking float trips down Ozarks streams might mistake for rocks are much more than that ? they're freshwater mussels, which hold potential for cleaning polluted streams.
Missouri Department of Conservation biologist Steve McMurray said a five-year safety inspection of Pomme de Terre Dam --which will requires stopping water releases --means mussels could be marooned and die.
"Our major concern is that the de-watering process downstream is going to leave a lot of mussel beds high and dry," he said. "They can kind of close up their shells and shut down for a while, but after a while they'll be affected."
McMurray and other freshwater mussel experts led an effort Thursday to rescue Missouri bivalves from a dried-out Pomme de Terre River. It was a chance not only to save them, but to study them.
And there's a lot to study when it comes to Missouri mussels.
There are not only a lot of species ? at least 67 in the state ? these mussels are also considered the most threatened aquatic creature because of habitat degradation as well as competition from fast-breeding Asian clams and zebra mussels, he said.
McMurray said there are at least 20 different mussel species in Pomme de Terre, with four listed as species of concern in Missouri and one as threatened. With water in the river below the dam expected to be low for a week, mussels sitting on exposed areas of the riverbed could not survive, the mussel expert ? properly known as a malacologist ? said.
The mussel rescue effort amounts to flagging mussels so their locations can be mapped, measuring and marking some to find again later and finding deeper pools where they could be deposited.
While rarer species would typically be given special treatment to make sure their new homes were suitable, the lack of a lot of manpower ? mid-week is a tough time to find volunteers ? meant more common mussels were tossed back into the water, McMurray said.
"I imagine by the end of the day when we're nice and cold, we'll just be tossing them back in," he said.
But the session provided some learning opportunities.
Not only did the researchers find several species, they had time to show off their favorite creatures. The names of mussels, many of which were created by 19th-century mussel harvesters, include plain pocketbook, fat mucket, black sandshell and deer toe.
At one point, MSU biologist and malacologist Chris Barnhart stood over a mussel and shot video of it displaying a waving "lure" that's part of its reproductive cycle.
Mussels need to find fish hosts for their larvae that hitch rides on a fish's gills until they grow large enough to fall off.
The "lure" that mimics a minnow is used to attract fish such as bass, Barnhart explained to MSU sophomore and Stream Team volunteer Shawn Wring.
"She can make blow it up like a balloon; it's like a little fish," Barnhart said while prying open a crack in the mussel's two shells. "Inside, there's probably a cool million baby mussels."
Because building a cofferdam below the dam outlet took longer than expected, the rescue effort shifted further downstream to the north end of the camping area below the dam.
It didn't take long to find several beds with a variety of mussels.
Picking a plain pocketbook that had a light green shell with radiating darker green bands from a red plastic bucket, the MSU professor said there's nothing plain about some mussels. He works with the Conservation Department to propagate native mussels.
"One of these is sort of gem quality," he said. "People don't think of freshwater mussels as being pretty, but they're kind of like Easter eggs."
And if a theory that he has about what mussels eat proves to be correct, this creature that is harvested for its shell ? which is used to create cultured pearls and, for some, jewelry ? could play a much bigger role for humans.
What mussels eat largely remains unknown. But Barnhart said he suspects mussels that can pump up to 100 gallons of water a day through their systems might eat bacteria.
If that's so, mussels could be used as natural water filters, he said.
"They could be removing E. coli from the water and other human pathogens," he said.
If that's the case, there could be more emphasis on making sure mussel populations remain healthy, he said.
Although much of the concern about declining mussel populations involves habitat degradation and competition from non-natives species, there's also concern populations are being pressured by illegal harvesting.
Commercial mussel harvesting is allowed in Missouri, but the Conservation Department hasn't issued a license in a decade, McMurray said.
But the experts said that based on poaching arrests in the Bootheel and the discovery of a rare specie in bags in the Sac River, it's likely Missouri mussels are being sold outside the state, he said.
As for interest in eating freshwater mussels, McMurray said he doubts there's much demand.
He's talked to only one person who enjoys eating freshwater mussels, he said.
The reason is simple, McMurray and Barnhart explained: Compared to saltwater mussels suh as clams, freshwater mussels are considerably more active, using a fleshy appendage known as a foot to move around, McMurray said.
"These guys have muscles in their feet," he said of freshwater mussels.
"The upshot is, they're tough as shoe leather," Barnhart said.
