A federally endangered species of fresh water mussel could be found in only one water way in the world; southwestern Virginia’s Clinch River. But 20 years ago, a chemical spill nearly wiped them out. Now biologists may be on their way to resurrecting them.
Biologist Tim Lane says freshwater mussels have “one of the most complex life cycles that I’m aware of I’m aware of the animal kingdom.”
Lane is southwestern Virginia’s Freshwater Mussel Recovery Coordinator for the Virginia Department of Game and Inland Fisheries. He’s leading a team, desperately trying to keep the golden riffleshell mussel species from going extinct.
To describe it, “It looks a lot like a Venus Fly Trap that’s trying to catch a fly when it lures its mate.”
Lane explains the delicate dance that begins when a pregnant female mussel lures an unsuspecting fish by shaking her delicious looking mane. But instead of getting a meal, the Fan Tail Darter, her favorite mark, becomes an unwitting host. He explains how it all works, “the female mussel” clamps down on the fish and deposits her larvae near its gills “Then she’ll just let the fish swim away.”
The larvae hang around on their host for a couple of weeks, sucking up nutrients, and getting a free ride, before they drop off into the river, where they’ll grow up to repeat the cycle. But it’s not like they don’t clean up after themselves.
Lane points out, “Mussels are really, really good at filtering water. Some species can filter 20 gallons a day by themselves."
A chemical spill in the Clinch River 20 years ago almost put an end to that for the delicate golden riffleshell. A truck carrying chemicals used to make foam rubber overturned, dumping is contents. Over the next two decades their numbers dwindled to almost nothing.
Then, last year, the team found just three surviving fertilized females in Indian Creek, a tributary of the Clinch. “So, it’s all we had left. If it wasn’t for the ones that were up here in the creek, it would have gone extinct.”
Trying to get these last remaining specimen to procreate the old fashioned way was way too risky. Fortunately, the department of US Fish and Wildlife knew of biologists in Kentucky doing in vitro fertilization on another species of endangered mussel.
“We carried the larva of this animal to a McDonalds parking lot, that’s where the transfer occurred into the rabbit serum (for the in vitro process.) So, this species, you know, hanging in the brink, but it worked so….”
They incubated the baby mussels at the Aquatic Wildlife Conservation Center in Marion, VA and when they were big enough, and that means just about a half inch long, they carefully placed seven hundreds of them back into their home creek, each one tagged with a tiny ID number on a grid.
Biologist, Sarah Colletti of the Virginia Department of Game and Inland Fisheries, who found the last 3 females alive there last year, is now carefully checking on their abundant offspring.
She compares the device she's using to a carpet sweeper as she moves it up and down along the river bottom. “It’s giving me the unique number for that mussel. So, now we can look at our chart and say this mussel that ends in these 4 numbers we can look at where it is on that grid.”
Colletti enjoys her work with the tiny creatures and she appreciates the magnitude of their predicament. “It’s like having one of the last Rhinos in your backyard. This species is not found anywhere else except this little creek.”
If this project is successful, there could soon be Golden Riffleshell mussels in several rivers in southwestern Virginia, where they once thrived.
Tim lane reflects that “Locals are quick to point out that this area is really important for natural resources, mostly coal and natural gas. But this is a natural resource too. And you would hope that the folks who live here would buy into that as well and say that this is something unique for us in the whole world