Sharing his vast knowledge of North American mussels, US Forest Service wildlife biologist Kim Tarter led a discussion at the Cranberry Mountain Nature Center Saturday on “Mussels: The ‘living rocks.’”
Tarter explained that North America has approximately 300 species of mussels – more than any other continent.
“No where else on the planet has as much mussel richness as we do here in North America,” he said. “Alabama is number one, Tennessee is two and Kentucky is third. Here in West Virginia, we only have sixty-three.”
While mussels may be found in the rivers of Pocahontas County, they are not found in the rivers in the Gauley Ranger District – Cherry, Cranberry and Williams.
“Why do we not have mussels in there?” he asked. “We are at a higher elevation and for mussels – the optimal habitat is a temperature of 70 degrees or higher. Also, there’s two different types of streams – a cold water stream, which is oligotrophic and a warm water stream which is eutrophic. Eutrophic – you have more action by the organisms, planktons, zooplanktons. That’s the beginning of the food chain for mussels.”
To identify a species, Tarter joked that it is easiest with an expert standing by your side in the river, but books will help, too. He also had samples of shells from different species to show the variety of shapes and sizes.
“This particular species, it’s called a washboard,” he said, showing a baseball sized shell. “In the Ohio River, I’ve never seen them, but it’s supposed to be as big as the lid of a five gallon bucket. It is the largest of our freshwater mussels.”
Other common names of mussels include: spectacle case, snuff box and monkeyface.
When examining mussels, its age is attainable in the same way as aging a tree – count the rings.
“They have growth lines on them so you can kind of count them like the growth rings in a tree,” Tarter said. “They grow during the summer seasons and then in the winter, they dig down deeper into the sand.”
Although there are more than 300 species of mussels in North America and they live between 70 and 80 years, freshwater mussels are on the endangered species list. One of the major factors leading to its endangered status is human activity in streams and rivers.
“We’ve constructed a lot of dams,” Tarter explained. “What happens is, you construct a dam along a river. Rivers have three characteristics – a cool habitat, riffle habitat and run habitat. Once you create a dam, the water is going to rise and so you basically eliminated the run and riffle habitats.”
Dams change the habitats populated by mussels as well as habitats for fish, which are hosts species for the mussels. Because mussels are essentially immobile, they rely on fish to spread them throughout the stream and into other rivers.
“They have a muscle in their body that’s called a foot,” Tarter said. “So, they’re somewhat mobile. I’ve seen them. Mussels can scoot around about 10, 15 feet. I’ve seen the track in the sand. It’s really cool. This organism cannot move itself enough, so it requires a host species – fish.
“A pregnant female has a pouch in her body and inside this pouch there are hundreds of babies called glochidia,” he continued. “So during the breeding season, the fish will come by and she is going to spit her babies out. The glochidia go out and clamp themselves on the gills and the skin of the fish. Once they reach a certain size, they drop off. That’s how God intends this species to distribute itself from the Ohio River at the bottom end where it meets the Mississippi all the way up to Pennsylvania.”
As filter feeders, mussels do the world a favor by cleaning the water of bacteria and microorganisms.
“It feeds on decay, organic material – leaves, branches – and then it feeds on plankton,” Tarter said. “There’s two siphons that stick out of the dorsal portion. One takes water in and the other pushes it out.”
Mussels are edible and are part of the diets of muskrats and river otters. They are also edible for the more adventurous humans.
“They’re really nasty,” Tarter said, laughing. “I’ve tried it just because I was curious and you might as well cut a hunk out of your shoe and chew it. It’s that tough.”
Mussels are also in demand in the fashion industry. Prior to the development of plastic, buttons were made out of mussel shells. The most popular use of mussels is to create pearls.
“Pearls are created naturally,” Tarter said. “What happens is an irritant goes inside the body of the mussel, a salt water mussel. It does not go back out so how the mussel reacts to it is, it forms a layer of lacquer. Most often it’s a grain of sand and as the years progress, it naturally forms a bigger ball or pearl. So pearls have this nice pretty, shiny shell.”
The largest pearl creation industry is in Japan where workers crush up shells to use as a catalyst to form pearls faster.
For more information on the mussels of Pocahontas County, Tarter may be contacted at the Gauley Ranger District at 304-846-2695 or through email at firstname.lastname@example.org
Suzanne Stewart may be contacted at email@example.com